Raisings of Ash Dykes from EL.227.25m To 231.25m including ... · including Allied Civil Works at...

Indian Institute of Technology,

Roorkee

Consultant

Raisings of Ash Dykes from EL.227.25m To 231.25m including

Allied Civil Works at RGTPP, Khedar, Hisar.

Volume-II

Technical specifications

HPGCL Rajiv Gandhi Thermal Power

Plant, Khedar, Hisar.

Purchaser

DOCUMENT NO. IITR/RGTPP/ CED/1217

REV. : R0 Vol-II/Sheet No. 1of 86


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Specifications for Raisings of Ash Dyke of Unit 1&2 from EL.227.25m To 231.25m

including Allied Civil Works at RGTPP, Khedar, Hisar.

1.0 Introduction:

1.1 The Khedar, Hisar Thermal Power Station, Khedar, Hisarhas two units with the total

installed generating capacity of 1200 MW The ash being generated from these units is

disposed off in the form of slurry in ash dykes located at a distance of about 3 km. away

from power house opposite to the thermal plant on the other side of Khedar, Hisar

adjacent to existing raw water reservoirs/ pump houses for the plant.

Ash generated from Unit 1&2 is being disposed off to a common ash disposal which has

been divided in two segments. As the ash fill level has already reached to the top of the

existing bunds therefore the raising of bund shall be done one by one. At the first

instance, one segment shall be raised and the other segment shall be put to use for the

disposal of ash slurry. After the completion of one segment in a time of 8 months, it shall

be put into use and the second segment shall be raised. All the ash shall be taken from

the ash ponds and the soil cover shall be taken from soil stockpile in ash dyke /raw water

reservoir area . However balance qty of soil shall be taken from stockpile in plant near

Wagon Tippler having a lead of about 6 KM.

1.2 Haryana Power Generation Corporation Ltd. ( HPGCL ) propose to raise the height of the

existing ash dyke of Units 1&2 from bund top EL. 227.25m, done in 1st raising over the

starter dyke with lagoon ash at Khedar, Hisar Thermal Power Station ( RGTPP ), Khedar,

Hisar.

HPGCL has appointed Indian Institute of Technology, Roorkee as engineering consultants

for this assignment.


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1.3 The scope of work comprises construction of 1straising of ash dyke on previously

constructed bund top from EL. 227.25m to EL. 231.25m including strengthening of starter

dyke and all associated works viz. excavation to required line and levels as per approved

design drawings, providing ash and selected earth from borrow areas, transportation,

placing, watering and compaction to required proctor density for forming the

embankment, raising of RCC Collector Wells, laying jute geo textile& turfing as

embankment, providing gabion walls, providing of 500 micron both face rough LDPE.

Geo textile, Geo-grid, Ramp with Road approach road from Barwala - Agroha Road,

peripheral road at top of the dyke, etc. The contractor shall furnish all labour, equipment,

materials, etc., all complete, as required for completing the work.

1.4 The 1straising now in ash dyke of RGTPP is proposed to be constructed from ash

borrowed from the settled ash in the existing ash pond and from the ash ponds shown in

the attached tender drawings. The ash from the Ash Ponds is to be lifted. The ash bund

will have earth protection layer at top. The proposed raised ash pond will be connected

with existing collecting wells one for each segment 1 and 2for collecting supernatant

water for recycling in the ash disposal system.

2.0 Main components of work :

Primarily the proposed ash pond work constitutes of the following main components:

a. Ash dyke, 4.0 m high from about EL. 227.25 m to EL 231.25 on the existing starter

dyke by reverse technique with Gabion walls, about 3.1 Km long, constructed from

ash borrowed from within the existing pond of unit 1&2. The bund top width will be

6.0 m and the side slopes will be about 2horizontal: 1 Vertical. The side slopes will

however, be firmed after detailed engineering and shall be as per the working

drawings yet to be released alongwith two ramps from existing GL to Top of New

Bund.

b. Top earth cover, about 500 mm thick, on the sloping faces of the embankments. The

earth is to be transported from stock pile at RWR and near WT’s inside RGTPP at his

own cost and as approved by Engineer-in-charge.


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c. Fly ash interlocking blocks/tilesprotection on the inside sloping face of the

embankment may be used.

d. Protective jute geo-textile 500 GSM with aperture of 100x 100 mm /grass turfing on

the outside face of the embankment.

e. Peripheral road on top of the bund and providing a ramp with road towards North

and West Side including approach road from Barwala – Agroha Road for facilitating

the movement of heavy loaded vehicles / lifting of Pond Ash.

LDPE Film of 500 micron with both sides rough surface may be used on upstream

side slopes (inner slopes) to make the ash ponds impervious as per guidelines of

MOE&F.

f. Strengthening of existing starter dyke by providingGabion walls with the toe of the

starter dykecomprising of mechanically woven double twisted hexagonal shaped,

zinc plus PVC coated steel gabion boxes of different sizes filled with suitable coal pick

stones (reject coal boulders to be supplied by the HPGCL) and passive support of ash

in between gabion wall and starter dyke.

g.

Providing and layinguniaxial high strength Geo-grid- 250 kn/m(with long term

strength of 150 kN/m) underneath the gabion walls.

h. Providing and laying Geo-Grid 250 KN per Mtr beneath the gabion wall.

i. WBM road 3.75m widehaving sub baseof 200 mm thickin two layers of stone metals

100 mm thick each including screening and binding material for the road on top of

the bund and ramp. However, an additional layer of GSB of 150 mm thick, BM 50

mm thick, PC 20 mm thick with seal coat, tack coat, priming as per the MORTH

specifications for the road to be constructed from Barwala – Agroha road to Eastern

Side of Dyke for providing road for heavily loaded vehicles.

j. Storm water drainage network.


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k. RCC aprons at ash slurry discharge points.

m

l.

n.

Installation of piezometers

Raising of existingRCC collection wells with steel approach/foot bridges& its supporting foundations and re-providing the same after raising of bund as per site requirement.

Maintenance of existing starter dyke, where ever damaged and to control &maintain either segment of ash pond in use during the raising of other segment of ash pond

3.0 Miscellaneous items also within the scope of present contract:

3.1 Locating, testing and transporting suitable earth from borrow areas, if required, for

specific use of top cover in ash dyke construction as detailed in the technical

specifications including the bid drawings.

3.2 Jungle clearance, removing trees, shrubs, vegetation, top organic ash / soil, etc. along the

dyke alignment for the required width of the bund at the base.

3.3 Excavating, grading, dressing and compacting the cleared / excavated ash / soil surfaces

in the dyke area to the required profiles as per approved construction drawings.

3.4 Constructing dyke embankments to the required configurations and profiles as per

approved construction drawings. The dyke shall be constructed of settled pond ash and

will have top cover of good earth ..


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3.5 The works covered in this specification shall include furnishing of all materials (except

materials supplied by Purchaser, if any, as stipulated in General Conditions of Contract),

labour, tools, plant and equipments, transportation, fabrication, supervision, construction

as per drawings including embedment of bolts, inserts, leaving holes, pockets, grooves,

chamfers as shown therein, site clearance, site grading and all incidental items not shown

or specified but reasonably implied of necessary for satisfactorily completing the project

as a whole.

3.6 It is not the intent to specify completely herein details of all the works covered under this

specification. Contractor’s scope shall include all other works not specifically mentioned in

the tender document but which are necessary for the satisfactory completion of the work as

a whole.

3.7 All works shall be done as per specification and as per approved and in a manner

acceptable to "Engineer”, who shall have the power to reject any work or material, which

in his judgment is not in full accordance therewith. In case of any conflict regarding the

interpretation of the intent or meaning of the specifications or drawings, Engineer shall

interpret such intent or meaning, which will be final and binding on the contractor.

3.8 Rectify and make good all defective work during the defects liability period.

3.9 Attending meetings at Purchaser’s / Consultant's office at RGTPP / Panchkula /Roorkee or

at any other place as fixed by Purchaser/Engineer as and when required for review,

discussions, co-ordination meetings, etc.

3.10 Collection & transportation of materials supplied by the Owner / Purchaser, if any, from

his stores located in the plant site or unloadingfrom trolley/trailer.

3.11 Making all necessary arrangements for access to the storage yard from the nearest

approach road and further to the actual site of work including dewatering as necessary,

and maintenance of same in order to facilitate transportation of machinery and

equipment such as cranes etc. assessing the suitability of already existing access roads.

3.12 Mobilization of concrete mixers, as required as per specifications, with all necessary

equipment.


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3.13 The work to be performed under the specification consists of providing all labour,

supervision, materials scaffolding, power, fuel, construction equipment, tools and plant,

supplies, transportation all incidental items as considered essential or specified or

reasonably implied or necessary for successful completion of the work including

contractor's supervision and strictly in accordance with the construction drawings and

specifications and as directed by the Engineer - in - Charge. The scope includes the

performance of all operations necessary for successful completion of works.

3.14 The drawings attached to the bid document provide a general idea about the work to be

performed under the scope of contract. These are preliminary drawings for bidding

purpose only and are by no means the final drawings or show full range of work under the

scope. The work has to be executed as per construction drawings with addition,

alternation and or/modification made from time to time as required and approved by the

Engineer - in - Charge and also according to any other drawings that would be supplied to

the contractor progressively during the execution of contract.

3.15 The technical specifications are intended to indicate the general description of the work,

quality and workmanship. The specification is not, however, intended to cover the

minute details.

4.0 Tender Drawings:

4.1 The following tender drawings are appended with the technical specification:

(i) Drg. No. CED/SM/HTPS/01:Reverse Raising of Ash Dykes General Arrangement &

details.

(ii) Drg. No. CED/SM/HTPS/01/R.

4.2 The above drawings are representative and only indicate the nature of work included in the

scope of this specification. The contractor shall do the construction only after issue of final

construction drawings by the Engineer - in – Charge after award of work.

5.0 Qualifying Requirement for Bidders:

5.1 The intending bidders should have requisite qualifying requirements as specified in the

detailed NIT. The bidder shall submit documentary evidence in support of his experience and

qualifying requirements.


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5.2 The purchaser reserves the right to request for any additional information and services and

reserves the right to reject the proposal of any bidders if in the opinion of the purchaser, the

information/documents furnished by the bidder in support of meeting the qualifying

requirements are incomplete or the bidder is not found qualified to perform the work

satisfactorily.

5.3 Notwithstanding anything stated above, the purchaser reserves the right to assess the

bidder's capability and capacity to perform the work and to relax the qualifying

requirements should the circumstances warrant such relaxation in the overall interest of the

purchaser.

5.4 Over and above the bidder shall be financially sound to execute the job.

6.0 Time of Completion and Schedule of Work:

6.1 Time of completion shall be 18 months (Overall). However, one pond has to be made

functional for discharging of ash slurry within the period of 8 months except the road work

on the top of the bund, laying of Jute Geo-Textile / turfing etc.The date of start of work shall

be reckoned from 10thday of issue of intimation for acceptance of the tender, irrespective of

the date of issue of detailed letter of allotment. The entire work under scope of this

specification including cleaning of all waste debris etc. shall be completed within the

specified time duration as specified in General Terms and Conditions.

6.2 The work shall commence within 10 days from the date of issue of letter accepting the

tender. This shall supersede such time as given in General Terms and Conditions.

6.3 The work must be preceded within such sections and at such times and in such order and

manner as described in these specifications and as directed by the Engineer - in - Charge.

6.4 The contractor on receipt of work order shall submit to the Engineer - in - Charge for his

approval a detailed work schedule showing how the contractor proposes to carry out the

work at the required pace and such approved schedules shall be strictly adhered to by the

contractor. The schedules are to be reviewed each month with the Engineer - in - charge to

ensure that the completion date shall be met or to indicate corrective steps (at no extra cost


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to the Purchaser) as the Engineer - in - Charge may consider necessary in order to maintain

the completion date. The Engineer - in - charge reserves the right to revise the schedule at

his discretion in order to suit project requirements.

6.5 All efforts shall be made to complete the works during daytime and normally no night

working shall be allowed. However, Engineer - in - Charge may consider granting permission

for working during night shifts on specific written request by the contractor. Night work

shall not entitle the contractor to any extra payment or extension of time. Where night

work is in progress, sufficient lights shall be provided to safeguard the workmen and the

public. Excavated areas, which are barricaded, shall be provided with red light to prevent

accidental falls. Where exigencies of work so warrant, the Engineer - in - Charge may also

direct contractor to work in extra shifts on holidays and in over time. It shall not entitle the

contractor to any extra payment.

6.6 If contractor fails to adhere to the stipulated time of completion specified in General Terms

and Conditions, he shall be liable to pay compensation for delay to the Purchaser as per

general terms and conditions.

7.0 Site Conditions and General Instructions:

7.1 Meteorological Data at the site as obtained from the nearest observatory at New Delhi are

as follows:

1. Purchaser/Owner The Chief Engineer / RGTPP Haryana Power Generation Corp. Ltd.

KHEDAR, HISAR(Haryana)-125122

2. Purchaser’s Consultant Indian Institute of Technology

(Department of Civil Engineering)Roorkee.

3. Project Title Reverse raising of Ash Dykes from EL 227.25 Mtr to 231.5 Mtr at RGTPP Khedar Hisar (Haryana)

4.

Location RGTPP, Khedar Hisar on NH-65 32 Km away from Hisar.


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5. Transport

a. Name of the Highway near which the site is located.

NH-65

b. Nearest railway station and gauge

Barwala

c. Nearest airport Delhi

6. Altitude 237 m from MSL

7. Ambient Air Temperature Max. : 460Celcius

Min. : 00Celcius

8. Relative Humidity Max. : 91 % Min. : 19 %

9. Rainfall South Westerly Summer Monsoons

a. Annual Mean 761 mm

b. Maximum for 24 hours Not available

c. Period Maximum rainfall from July to September

10. Wind Data As per IS:875 (Pt-3)

a. Maximum Wind Velocity.

47 m/s (170 Kmph )

b. Prevailing wind direction N-W, W, S-W, S-E, E, N-E & N

11. Seismic Zone Zone IV as per IS:1893

12. Climate Hot and Dry


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7.2 The bidder shall satisfy himself regarding the accessibility of the site and the local working

conditions at the site. It is for the contractor to construct necessary roads/paths etc. for

making access to the project/sites at his own cost.

7.3 The bidder is advised to visit the project site with the prior permission from the Chief

Engineer/RGTPP,Khedar, Hisarin order to get acquainted himself with site conditions and for

obtaining all types of necessary information for proper execution of the work.

7.4 The bidder should particularly satisfy himself regarding the quantum of work involved,

transportation, disposal, handling and storage of material, availability of labour, water,

electric power, roads and uncertainties of weather or similar physical conditions of the site,

the configuration and conditions of the ground, the character, quality and quantity of

surface and sub - surface materials to be encountered including the water level below

existing surface, the type of equipments and facilities needed during the progress of the

work and all other matters, which can in any way effect the cost thereof under this

specification. Ignorance of site conditions shall not be accepted as a basis of claim for any

compensation of any nature.

7.5 The contractor shall make his own arrangements for construction and potable water. He

shall also ensure that only the good quality of water as per the requirement of the

specifications is used. If it is given by Deptt recovery @ 1% of the gross value of work shall be

made from the bills

7.6 During the course of contractor's work, other works may also be in progress at site. The

contractor is to use his best efforts to work in harmony with others and in the best over all

interest of the project.

7.7 The information given to the bidders in technical specification comprising of all sections is

meant to serve as a guide, it is, therefore imperative that the bidder shall obtain and

examine himself all the data, information and particulars required for the satisfactory

execution of the work under this specification, however no claim on account of any

deviation in the actual data being at variance with that furnished in the bid shall be

entertained

7.8 All material supplied by the contractor shall be best quality and shall conform to relevant

Indian Standard Codes of Practice, this specification and construction drawings. Approval in

writing from the Engineer - in - Charge shall be obtained by the contractor before any

alternative or equivalent material is used other than that specified in the construction

drawings/specification.


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7.9 During inclement weather contractor shall suspend concreting, plastering, laying of ash,

impervious layer, sand layer etc. for such time as the Engineer - in - Charge may direct and

shall protect all works from damage during the construction. No claim whatsoever on this

account shall be entertained.

7.10 If the work is suspended by reason of rain, strike lockout or any other cause, the contractor

shall take the precautions necessary for the protection of wok and at his own expense shall

make good any damage arising from any of these causes.

7.11 Deviation limit for the quantum of works as a whole shall be +10% of the total quantum of

work as per contract. The quantity for individual items can vary to any extent.

7.12 Guarantee Period: The period of guarantee for work covered in this specification shall be

one year after the completion of the work as a whole and its acceptance by the Engineer - in

- Charge.

7.13 The bidder is expected to get clarified any doubts about the specification, site conditions and

other tender documents etc. before bidding by discussion and the same shall be recorded in

writing with the Purchaser in respect of the interpretation of any portion of the document.

7.14 The contractor shall bear the payments required for any of the Royalty/or cost of land/or

rent/or any other charge for the borrow area materials and nothing extra shall be payable

7.15 Testing Laboratory: The contractor shall establish testing laboratory required for the

purpose of carrying out tests regularly during the period of construction and nothing extra

shall be payable to the contractor for establishing the laboratory.

7.16 Escalation: The rates quoted shall be firm and no escalation in the rates and costs shall be

allowed except otherwise specified in General Terms and Conditions. No extra payment

shall be allowed for extra shifts or night shifts etc.

8.0 Purchaser's Scope of Supply

8.1 The Engineer - in - Charge shall hand over site to the contractor within 7 days of the date of

issue of letter accepting the tender for enabling the contractor to make arrangements for his

store sheds, cements sheds, temporary office etc.

8.2 The Cement and reinforcement steel required for the work shall be arranged by the

contractor.


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9.0 Layout and Levels

9.1 The layout and levels of the ash dyke shall be made by the contractor at his own cost from

reference point and the benchmark given to him at site by the Engineer - in - Charge. The

contractor shall provide necessary help in instruments materials and men to the Engineer -

in - Charge for checking the correctness of detailed layout and levels. However, checking by

the Engineer - in - Charge shall not relieve the contractor of his responsibility for correct

execution of works as per construction drawing and he shall be solely responsible for

correctness of layout and levels.

9.2 Surveying

9.2.1 As soon as the contract is awarded, the Contractor shall mobilize necessary instruments and

personnel to arrange for accurate surveying of the area where the bunds are to be located in

the presence of the Engineer-in-Charge or his authorized representative. Levels shall be

obtained at every 10m intervals along the length of the bund and at every 5m intervals along

the width of the bund and shall cover the complete plan area likely to be occupied by the

bund. The Contractor shall plot all these levels and prepare longitudinal section at center line

of the proposed bund and cross sections at every 10m interval and shall submit four sets of

the same to the Purchaser.

9.2.2 The survey shall be repeated after excavation & preparation of foundation for ash bund is

completed as per clause 9.2.1. Four copies each of the longitudinal section and cross

sections shall again be submitted to the Purchaser.

9.2.3 Cross sections and longitudinal section as approved by Purchaser shall from the basis for

calculation of the quantities for the bund for payment purposes.

10.0 Diversion of ash slurry water from construction area and drainage of storm water from

catchments of bunds during execution

10.1 Construction of Diversion Bund for diversion of flow of ash slurry

The construction of work shall be planned in such a way that ash slurry/water in ash pond

remains at safe distance away from construction area. Ash slurry in ash pond is continuously

being discharged from RGTPP and clear water after settlement of ash is taken out through 2

nos. decantation wells provided for disposal of decanted water. Construction area shall be


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kept dry by providing protection bund of adequate size with locally available pond ash and

soil (to be brought from outside at his own cost) at safe distance away from the construction

area and dewatering, if required. The work shall be proceeded in such a manner that one no.

decantation well is always available for disposing the decanted water from ash pond. After

completion of the entire construction activities, the temporary protection bund shall be

dismantled.

10.2 The catchment area of the pond itself might yield large quantities of water during heavy

rains. This water has to be properly drained off during the execution to facilitate

uninterrupted construction activities. The contractor shall estimate the run-off from

meteorological data as specified above and shall design a scheme for interception and

disposal of this water and submit the same for the approval of the purchaser. After the

scheme has been approved by the purchaser, this temporary, work shall be undertaken by

the contractor at his own cost. However, such approval by purchaser does not absolve the

contractor from his responsibility for the adequacy of the design of the drainage system. This

temporary drainage system shall be dismantled after the bund construction is completed in

all other respects. Sluices or other openings left in the body of the bund shall be plugged

with concrete of grade 1:2:4 and grouted to the complete satisfaction of the purchaser.

10.3 Dewatering if required during the execution of the entire activities shall be in the scope of

the contractor and nothing extra on this account shall be paid. The contractor is advised to

visit the site of work before submitting the tender to acquaint himself regarding the site

conditions.

10.4 The work to be performed under the specification consists of providing all labour,

supervision, materials, scaffolding, power, fuel, construction equipment, tools and plant etc.

11.0 Excavation :

11.1 Excavation in Soil

11.1.1 The specifications for excavation in soil shall apply to excavation work in rock also, except for

the bottom of excavation, where depending on the type of rock, over-breaks up to a

maximum depth of 0.3m below the required level may be allowed by the Engineer-in-Charge

at his discretion and paid accordingly.


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11.1.2 Sides and bottoms of excavation shall be cut sharp and true to line and level. Undercutting

shall not be permitted. When machines are used for excavation, the last 300 mm before

reaching the required level shall be excavated manually or by such equipment so that soil at

the required final level shall be left in its natural condition. Suitability of strata (at the

bottom of excavations) for laying the foundation thereon shall be determined by the

Engineer - in - Charge.

11.1.3 Excavation for foundation shall be to the bottom level of lean concrete or as shown in

construction drawings and as directed by the Engineer - in - Charge. The bottom level of all

excavations shall be trimmed to required levels and when excavation is carried below such

levels, by error, it shall be brought back to specified level by filling with concrete M15 grade

as directed by the Engineer - in – Charge at his own cost.

11.1.4 The Contractor shall ascertain for himself the nature of materials to be excavated and the

difficulties, if any, likely to be encountered in executing this work. Coffer dams, sheeting,

shoring, bracing maintaining suitable slopes, draining etc. shall be provided and installed by

the Contractor, to the satisfaction of the Engineer - in - Charge.

11.1.5 All excavation for installation of underground facilities, such as piping, sewer lines, drain

lines etc. shall be open cuts. For deep and huge excavations and in other excavations, if

required by the Engineer - in - Charge, the Contractor shall submit for approval an

"Excavation Scheme” showing the methodology to be adopted for excavation in order to

maintain the stability of side slopes, means for ensuring safety of existing facilities nearby,

dewatering etc. However, the Contractor shall be fully responsible for the scheme

irrespective of any approvals granted. Benching shall be provided for deeper excavation

whenever required.

11.1.6 When excavation requires bracing, sheeting or shoring etc., the Contractor shall submit to

design and drawings to the Engineer - in - Charge, showing arrangements, details of

proposed installation and structural safety. The Contractor shall also furnish all supporting

design calculations as called for and shall not proceed until he has received written approval

from the Engineer-in-Charge. However, the responsibility for adequacy of such bracing,

sheeting, shorting etc., shall rest with the contractor, irrespective of any approval of the

Engineer-in-Charge.

11.1.7 The Contractor shall have to constantly pump out any water collected in excavated pits and

other areas due to seepage, rain water, springs etc., and maintain dry working conditions at

all times until the excavation, placement of lean concrete, reinforcement, shuttering,


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concreting, backfilling is completed. The Contractor shall remove all sludge / muck from the

excavated areas to keep the work area dry. The Contractor, if required, shall employ sludge

pumps, for this purpose.

11.1.8 The Contractor shall have to remove all materials arising from excavations from the vicinity

of the work either for direct filling, stacking and subsequent filling or for ultimate disposal as

directed by the Engineer-in-Charge. In no case, the excavated soil shall be stacked within a

distance of 1.5m from the edge of excavation or one-third the depth of excavation

whichever is more. Material to be used for filling shall be kept separately.

11.1.9 For purpose of excavation of earthwork, the term soil shall apply to all kind of soil containing

any percentage of kankar, moorum or/and shingle etc.

11.1.10 Disposal of Surplus Earth

The Contractor shall arrange to transport the surplus excavated soil remaining after

backfilling to the area within a total lead of 500m including all lifts etc. as directed by the

Engineer-in-Charge. The soil so transported shall be stacked and levelled neatly. The unit

rate for excavation shall include loading, transporting, unloading and stacking, levelling

complete. The disposal area shall be intimated by the Engineer-in-Charge.

11.1.11Measurement and Payment

(a) All excavation shall be measured net in cubic meter. Dimension for the purpose of

payment shall be reckoned on the horizontal area of the excavation at the base for

foundation of the walls, columns, footings, tanks, rafts, or other foundations/structures

to be built, multiplied by the mean depth from the surface of the ground in accordance

with the drawings. Excavation for side slope wherever provided for safety of excavation

shall not be paid. The contractor shall make such allowance in his rates to provide for

excavation in side slopes keeping in mind the nature of the soil and safety of excavation.

If pay line of adjacent foundations overlap, the over-lapped portion shall be paid only

once. The length, width and depth of excavation shall be measured in meter correct up

to second place of decimal. The volume of excavation calculated in cum. shall be

rounded of to the second place of decimal. Nothing extra shall be payable for slope,

shoring, strutting, dewatering etc. irrespective of whatever is provided.


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12 Filling, Back Filling and Site Grading:

12.1 General:

All fill material will be subject to the Engineer’s approval. If the Engineer rejects any material,

the Contractor shall remove the same forth with from the site at no extra cost to the Owner.

Surplus fill material shall be deposited/ disposed off as directed by the Engineer after the fill

work is completed. No earth fill shall commence until surface water discharges and streams

have been properly intercepted or otherwise dealt with as directed by the Engineer.

12.2 Material:

To the extent available, selected surplus soils from excavated materials shall be used as

backfill. Fill material shall be free from clods, salts, sulphates, and organic or other foreign

material. All clods of earth shall be broken or removed. Where excavated material is mostly

rock, the boulders shall be broken into pieces not larger than 150mm size, mixed with

properly graded fine material consisting of minimum or earth to fill up the voids and the

mixture used for filling.

If any selected fill material is required to be borrowed, the Contractor shall make

arrangements, for bringing such material from outside borrow pits. The material and source

shall be subject to prior approval of the Engineer. The approved borrow pit area shall be

cleared of all bushes, roots of trees, plants rubbish etc. top soil containing salts/ sulphate

and other foreign material shall be removed. The materials so removed shall be burnt or

disposed off as directed by the Engineer. The Contractor shall make necessary access roads

to borrow areas and maintain the same, if such access road does not exist, at his cost.

12.3 Filling in pits and trenches around foundations of structures, walls etc.

As soon as the work in foundations has been accepted and measured, the spaces around the

foundations, structures, pits, trenches etc, shall be cleared of all debris, and filled with earth

in layers not exceeding 15cm., each layer being watered, rammed and properly

consolidated, before the succeeding one is laid. Each layer shall be consolidated to the

satisfaction of the Engineer. Earth shall be rammed with approved mechanical compaction

machines. Usually no manual compaction shall be allowed unless the Engineer is satisfied

that in some cases manual compaction by tampers cannot be avoided. The final backfill


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surface shall be trimmed and leveled to proper profile as directed by the Engineer or

indicated on the drawings.

12.4 Filling in trenches

Filling in trenches for pipes and drains shall be commenced as soon as the joints of pipes and

drains have been tested and passed. The backfilling material shall be properly consolidated

by watering and ramming, taking due care that no damage is caused to the pipes.

Where the trenches are excavated in soil, the filling from the bottom of the trench to the

level of the centerline of the pipe shall be done by hand compaction with selected approved

earth in layers not exceeding 8 cm; backfilling above the level of the centerline of the pipe

shall be done with selected earth by hand compaction or other approved means in layers not

exceeding 15 cm.

In case of excavation of trenches in rock, the filling up to a level 30-cm, above the top of the

pipe shall be done with fine materials, such as earth, moorum etc. The filling up of the level

of the centerline of the pipe shall be done by hand compaction in layers not exceeding 8 cm.

whereas the filling above the centerline of the pipe shall be done by hand compaction or

approved means in layers not exceeding 15cm. The filling from a level 30 cm. above the top

of the pipe to the top of the trench shall be done by hand or other approved mechanical

methods with broken rock filling of size not exceeding 15cm mixed with fine material as

available to fill up voids.

Filling of the trenches shall be carried simultaneously on both sides of the pipe to avoid

unequal pressure on the pipe.

12.5 Measurement and Payments

12.5.1 Backfilling on the sides of foundations of columns, footings, structures, walls, tanks, rafts

trenches etc. with available excavated material shall be paid for separately. Measurement

for payment shall be based on volume calculations. The length, width and depth of backfill

shall be measured in meter correct upto second place of decimal. The volume of backfilling

calculated in cu.m. shall be rounded of to the second place of decimal.

12.5.2 Backfilling to be done with borrowed earth, wherever shown in the drawing shall be paid as

per the actual compacted volume subject to maximum as shown in the drawing which will


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include preparation of borrow area, excavation, loading, transportation, unloading, laying in

layers, compacting, royalty/taxes etc. complete as per specification

14.0 Impervious Materials for Zone – I:

14.1 Borrow Areas:

All the material required for the soil cover for the ash fill bund shall be taken from stock pile

near the ash dyke / raw water reservoir and balance quantity of soil to be taken from plant

area near WT’s.

14.2 Preparation of Borrow Areas:

All areas required for borrowing earth for ash dyke shall be cleared of all trees and roots,

bushes rubbish and other objectionable materials. Particular care shall be taken to exclude

all organic matter to be placed in the ash dyke. The cleared areas shall be maintained free of

vegetation growth during progress of the work.

14.3 Stripping of Borrow Areas:

Borrow area shall be stripped of topsoil and any other matter which is unsuitable for the

purpose for which the borrow area is to be excavated. The stripping operation shall be

limited only to designated borrow areas and dumping of stripping materials shall be done as

per the direction of the Engineer - in - Charge.

15.0 Construction of Ash Dyke:

15.1 Surface Treatment of Pond Ash: The top surface of ash in the pond is at about EL + 227.25m

in general near starter dyke of proposed ash dyke. But due to uneven filling, the top level of

ash may be more or less than EL + 227.25 M in some places near starter dyke and within the

base strip of proposed dyke. The base area for ash dyke construction shall be treated to

ensure satisfactory foundation beneath ash fill by removing all vegetation and 0.30 M top

layer of settled ash within the base strip of the proposed dyke to ensure satisfactory

foundation of ash dyke.

The vegetation and excavated top settled ash should not be used for construction purpose.

The exposed ash material in the base strip shall be tested by the contractor as specified in


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CI.16.13.4. If the excavated surface thus exposed is having higher moisture content than the

Optimum Moisture Content (OMC) shall have to be left exposed to dry up to attain OMC,

and after attainment of OMC or otherwise if the water content of the exposed ash is not

higher than OMC shall immediately be compacted with compaction equipment to achieve

95% compaction of maximum standard proctor dry density. The test for compacted ash in

the base strip shall be carried out as per CI.16.13.4

15.2 Spreading and Compaction:

The ash dyke shall be constructed from the ash excavated from the ash pond and stilling

ponds. The ash is stockpiled in the dyke area and the same is spread horizontally with

dozers in layers of 20 cm thickness. The spreading shall be done on the entire width of the

dyke. After spreading, ash shall be compacted with 8/10 tones vibratory roller or any other

suitable means to achieve a minimum field density of 95% of maximum proctor dry density

obtained in the field laboratory. The test for ascertaining the geo - technical properties of

the ash shall be carried out as per CI.15.13.4.

15.3 Benching:

On the areas where as embankment is to be constructed adjacent to the natural soil, the

slope should be benched with approximately 200 mm interval to ensure that new ash

embankment is properly tied into the existing slopes.

15.4 Soil Cover (Impervious Zone):

The major risks associated with compacted ash dyke are erosion of the ash both internally

and externally and liquefaction. Ash dyke shall be covered with available soil cover of 0.5M

thicknesses and compacted to maintain required dry density of 85% of maximum standard

proctor dry density.

15.5 Compaction Equipment

The compaction shall be carried out using pneumatic rollers or vibratory rollers for

compacting ash/ cohesion less materials and sheep foot rollers or pneumatic rollers for

compacting cohesive materials. Rolling shall be commenced from outer edge and progress

towards centre. The engineer based on the results of the test section shall as finally approve

the number of passes. However, in no case the number of passes shall be less than 8.


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15.5.1 Pneumatic Rollers

Pneumatic rollers shall have four wheels equipped with pneumatic tyres, and a body

suitable for ballast loading so that the load per wheel may be varied as necessary from 7 to

11 tonnes.Tyre pressure shall not exceed 2.5 Kg/cm², as greater pressure tends to cut ash

surface. The tyres shall be of such size and ply as can be maintained during rolling

operations, a tyre pressure not greater than 1.5 Kg/cm² for a 11 tonnes wheel load. The

roller wheels shall be located abreast and each wheel and tyre shall be mounted in such a

way that all wheels exert approximately equal loads, when traversing uneven grounds.

15.5.2 Vibratory Rollers

Vibratory rollers shall have dead weight 7 to 15 tonnes and the vibrators shall have

frequency between 1100 and 1800 pulses minute and amplitude of vibration shall be

between 0.5mm and 1.5mm.

15.5.3 Sheep Foot Rollers

Each drum of a roller shall have an outside diameter of not less than 1.5m and shall not be

more than 1.8m in length. The space between two adjacent drums when on level surface

shall neither be less than 30 cm nor more than 40 cm. Each drum shall be free to pivot

about an axis parallel to the direction of travel.

At least one tamping foot shall be provided for each 600 cm² of drum surface. The shape

measured on the surface of the drum, between the centers of any two adjacent tamping

feet, shall not be less than 25 cm. The length of each tamping foot from the outside surface

of the drum shall be maintained at not less than 25cm. The cross sectional area of each

tamping foot shall not be more than 60 cm² at a plane normal to the axis of the shank 15cm

from the drum surface, and shall be maintained at not less than 45 cm² and not more than

60cm² at a plane normal to the axis of the shank 20 cm from the drum surface.

The weight of a roller when fully loaded shall not be less than 7 tonnes per drum. The

loading used in the roller drums and operating of rollers shall be as required to obtain the

desired breakdown and compaction of materials. If more than one roller is used on any one

layer of fill, all rollers so used shall be of the same type and essentially of the same

dimensions. Tractors used for pulling rollers shall have sufficient power to pull them at a

speed of about 4 Km/hour with drums fully loaded. During the operation of rolling, the


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spaces between the tamping feet shall be kept clear of materials, which could impair the

effectiveness of the tamping rollers. If the rollers used are at tandem, the tamper spacing

shall be set so that the circumferential rows of the rear drums are in line with the mid-point

between the circumferential rows on the forward drums.

15.6 Dressing and Trimming of the Slopes

15.6.1 The outer slopes of the embankment shall be neatly dressed to line as the placing of the fill

progresses. Compaction shall extend over the full width of the embankment and the

material in the slopes shall be compacted as for the rest of structure. To ensure proper

compaction at the outer edge, the fill shall be constructed for a minimum of 500 mm extra

width on edges and the outer edge dressed to true width and slope after compaction. No

soil cover slope shall be left without trimming to design slope. Slopes shall be maintained

until final completion and acceptance. Any material that is lost by weathering or due to any

other cause shall be replaced and make good at his own cost. The trimmed materials are

permitted for reuse in the embankment. No separate payment will, however, be made for

forming extra width offsets or trimming the slopes and the unit rates for the embankment

work shall, therefore, provide for the same.

15.6.2 The soil cover shall be constructed either simultaneously with the ash fill or separately after

the ash fill is compacted in layers of specified thickness. If laid separately the trimmed slopes

of the bund should be scarified and 200mm deep keys should be provided at spacing not

exceeding 3meter center-to-center both across and along the slope with dragline bucket or

other suitable method and nothing extra shall be paid on this account. The soil layer shall be

placed in thickness not more than 200mm and properly compacted using suitable

compactors.

15.6.3 In those parts of the ash bund which are inaccessible to the specified rolling equipment, e.g.

around and in contact with structures, and in proximity to structures where the rolling

equipment will not be permitted to operate, compaction shall be accomplished by

mechanical tampers of approved type. Rollers will not be permitted to operate within three

meter of concrete structures, and all fill within this distance shall be spread in layers not over

75 mm thick when loose. The moisture content of the material and the amount of tamping

shall be such as to produce a degree of compaction equal to that specified for rolled fill.


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15.7 Construction Joints

A construction joint shall mean a compacted fill surface made to a slope exceeding the slope of

bonding surface but not exceeding 1 vertical to 3 horizontal. A bonding surface shall mean a

compacted fill surface made to a slope not exceeding 1 vertical to 8 horizontal.

Prior to placing a layer of fill material against previously placed fill at any construction joint,

the surface materials at the joint shall be cut back horizontally to a distance sufficient to

accommodate a layer of the fill material to be placed; but in any event to a horizontal

distance one meter in excess of that required to expose a dense face of the previously

placed and compacted fill and in height equal to the thickness of the layer to be placed.

All loosened and dried ash/soil from the surface of the construction joint shall be removed

or reconditioned for use. Prior to placing each layer on the freshly exposed surface, such

surface shall be scarified if necessary. The freshly placed fill at construction joints shall be

placed and compacted as specified except that the rolling pattern of the compaction

equipment shall be so adjusted in the region of the joints that compaction shall be carried

over the edge of the newly placed fill into the previously placed fill by a minimum of one

meter measured horizontally.

No cutting back and tying will be required at bonding surfaces, but all loose material shall

be removed from such surfaces, before placing the subsequent layer.

15.8 Internal Drainage System:

For efficient functioning of the raised embankment, the internal drainage system should

operate and continue to operate efficiently. The internal drain consisting of Gabion wall/

rock , geo-textile, and The seepage discharge from internal surfaces must be controlled with

filters that permit water to escape freely and also hold particles in places and the piezo -

metric surface on the downstream of the dyke

15.9. General Requirements The Contractor shall furnish all labour and materials required for the complete performance of the work in accordance with the drawings, schedule of item and as described herein.Anddirected by the Engineer - in - Charge.


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15.10 Jute/Geotextile/Turfing:

After completion of the final section including earth cover turfing on outer side shall be

provided.

Laying of jute geo-textile 500 GSM with aperture size100mmx100mm on the downstream

slopes of ash dyke to be held in position by wooden pegs of suitable size at 3 meter center to

center followed by providing and spreading, seedlings of approved species as par drawing,

watering etc. complete till the grass establishes itself uniformly. The specifications for these

works are covered in subsequent clauses.

15.11 Inspection & Tests

It is necessary to maintain a thorough check on the quality of fill material placed in the dyke

and that the in - situ properties of the materials after compaction shall be obtained for

comparison with design assumptions. To achieve these objectives, a programme of field -

testing and inspection shall be planned by contractor to affect quality control.

15.12 Scope of Testing and Inspection:

Field control of fill materials will require visual and laboratory checks. The checks on the

effectiveness of placement and compaction procedures shall require to be made by field

density tests at prescribe intervals. The control shall be both of the method type and/or an

end result basis.

15.13. Field Test Laboratory, Data, Records and Reports

The contractor shall establish a test laboratory at site where the tests can be performed

regularly. The results of these tests shall act as a guideline for day to day working.

Experienced staff that is approved by Engineer -in - Charge shall carry out the tests. Nothing

extra shall be payable to the contractor for establishing the laboratory.

15.13.1 Record of tests carried out for the borrow area materials and embankment placing

operations shall be maintained in order to have a continuous check on suitability of fill

materials and quality of the fill. The record shall be maintained on the forms specified in

Annexure - I. The rates quoted for the various items shall be inclusive of cost of carrying

out the operations as specified in this specification.


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15.13.2 Frequency of Testing:

15.13.3Control tests shall be carried out as indicated below:

(a) Testing of Ash in the Base Strip: After stripping by removing top 0.5 m(minimum) of

ash and compacting the stripped surface the compacted ash samples in two rows

from every 100 m R.D shall be tested to confirm the attainment of 95% of maximum

standard proctor density.

(b) Field density tests shall be particularly and specially made in the following areas:

(i) Wherever embankment operations are concentrated i.e. where two or more

layers are placed one over the other on the same day.

(ii) Wherever the degree of compaction is doubtful

15.14 Settlement Allowance:

15.14.1The settlement allowance of 2% of proposed height of dyke shall be provided by increasing

the height of dyke. The base width of dyke shall not be increased to maintain the design

slopes indicated in the drawing for additional height as settlement allowance. If the dyke is

raised in more than one season, provision for settlement shall be made in the last season's

construction by slight steeping slopes near the top. Nothing extra on this account shall be

paid.

15.15 Method of Measurement and Payments

16.15.1Separate measurement shall be made for the material of each zone/segments. No

separate payment for lead or lift involved in the work shall be made. The length, breadth

and height shall be measured in meter correct up to second place of decimal. The volume

arrived at from these measurements in cu.m. shall be rounded off to the second place of

decimal. Deduction for settlement shall be made and net quantity payable shall be

calculated. The rates quoted for the various items shall be inclusive of cost for

establishment of the testing laboratory and carrying out the test as specified in this

specification.


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16.0 Technical Specifications for Mechanically Woven Double Twisted, HexagonalShaped,

Zn+PVC coated Steel Gabions:

16.0 Providing mechanically woven, double twist hexagonal shaped, wire mesh gabions, mesh

type 10x12, Zn+PVC coated, for retention purpose.

16.1 Description

This work shall consist of furnishing, assembling, and filling mechanically woven double twist

hexagonal wire mesh gabions with rock as specified in the contract to the dimensions, lines

and grades shown on the plans, or as determined by the engineer. These specifications are

mainly in accordance with International Standards EN 10223, EN 10244.

16.2 Material- Gabions: Li

d

Fig. 1 Diaphragm

End

Back

H

End

Front

L

W


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16.2.1 Wire:

All tests on the mesh, lacing wire and selvedge wire must be performed prior to

manufacturing the mesh.

Tensile strength: The wire used for the manufacture of Mesh shall have a tensile strength

minimum 350 N/mm2 in accordance with EN 10223-3. Wire tolerances (Table 3) are in

accordance with EN 10218 (Class T1).

Elongation: Elongation shall not be less than 10%, in accordance with EN 10223-3. Test must

be carried out on a sample of at least 25 cm length.

16.2.2 Internal Connecting Wires:

Cross Ties/ stiffener wire: Diameter 2.2 mm, Zinc coated wire with PVC coating,

3.2mm when measured with PVC coating.

16.2.3 Zinc Coating

i). Zinc coating: Minimum quantities of Zinc shown at Table 1 shall meet the requirements of

EN 10244-2 (Table 1 and Class A).

ii). Adhesion of zinc coating: The adhesion of the zinc coating to the wire shall be such that,

when the wire is wrapped six turns around a mandrel having four times the diameter of the

wire, it does not flake or crack when rubbing it with the bare fingers in accordance with EN

10244.

16.2.4 PVC (Polyvinyl Chloride) Coating

PVC coating thickness: Nominal – 0.5 mm, Minimum – 0.38 mm; Specific weight: 1.3 kg/dm3

– 1.35 kg/m3 in accordance with ISO 1183. Hardness: between 50 and 60 Shore D, according

to ISO 868.

Tensile strength: Higher than 21 MPa, according to ISO 527 Elongation at

break: not less than 200% in accordance with ISO 527. UV Stabilized


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16.2.5 Wire mesh (10x12 mesh type):

Zinc +PVC coated

Mesh type “D”(mm)

Diameter of wire (Inner / Outer wire)

Mesh wire(mm) Selvedge wire Lacing wire(mm)

(mm)

10X12 100mm 2.7/3.7 3.4/4.4 2.2/3.2

Mesh opening: Nominal Dimension D = 100, as per Fig. 2

Tolerances in Mesh Opening size: - 2% to +2%

Figure (2)

Mesh

Type Nominal Dimension D

10x12 100mm

D

16.2.5 Tolerances

Wire: wire diameter tolerance and minimum zinc coating requirement shall be as per

following table:

Table (1)

Wire Diameter mm 2.2 mm 2.7 mm 3.4 mm


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Wire Tolerance(+)mm 0.06 0.06 0.07

Minimum Qty of Zinc (gm/m2 ) 230 245 265

16.2.7 Standard Sizes

Standard sizes (LengthxBreadthxHeight) of gabions are 4mx1mx1m, 3mx1mx1m,

2mx1mx1m, 1.5mx1mx1m, 4mx1mx0.5m, 3mx1mx.5m and 2mx1mx0.5m

16.2.8 Tolerance in gabion dimensions

+ 5% in all dimensions (length, breadth and height) shall be allowed as tolerance forGabion

units.

16.2.9 Fabrication

Gabions shall be manufactured with all components mechanically connected at the

production facility. The front, base, back and lid of the gabions shall be woven into a single

unit. The ends and diaphragm(s) shall be factory connected to the base. The lid may be a

separate piece made of the same type mesh as the basket. All perimeter edges of the mesh

forming the basket and top, or lid, shall be selvedge with wire having a larger diameter.

Gabion is divided into cells by means of diaphragms positioned at approximately 1m centres.

The diaphragms shall be secured in position to the base so that no additional lacing is

necessary at the jobsite.

Table (2) Typical Gabion sizes (10 X 12 -mesh type)

Length, m Width, m Height, m Number of

Diaphragms

4.0 1.0 1.0 3

3.0 1.0 1.0 2


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2.0 1.0 1.0 1

1.5 1.0 1.0 0

4.0 1.0 0.5 3

3.0 1.0 0.5 2

2.0 1.0 0.5 1

16.3 Construction Requirements

Gabion filling and lacing and erection at site should be strictly as per the instruction of

approved (by engineer) manufacturer’s instructions as per the site specific requirements.

16.3.1Assembly

Gabions are supplied folded flat and packed in bundles. Larger units may be supplied in rolls.

The units are assembled individually by erecting the sides, ends, and diaphragms, ensuring that

all panels are in the correct position, and the tops of all sides are satisfactorily aligned. The four

corners shall be connected first, followed by the internal diaphragms to the outside walls.

The procedure for using lacing wire consists of cutting a sufficient length of wire, and first

looping and/or twisting the lacing wire to the wire mesh. Proceed to lace with alternating

double and single loops through every mesh opening, pulling each loop tight and finally

securing the end of the lacing wire to the wire mesh by looping and/or twisting. Refer figure 3.

Figure (3)

16.3.2 Installation

After initial assembly, the gabions are carried to their final position and are securely joined

together along the vertical and top edges of their contact surfaces using the same connecting


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procedure(s) described earlier. Whenever a structure requires more than one layer, the

upper empty baskets shall also be connected to the top of the lower layer along the front and

back edges of the contact surface using the same connecting procedure(s) described in

Section 1.3.1.

16.3.3 Filling

Gabions shall be filled with rock as specified .Refer clause 2.0

16.3.4 Internal Connecting Wires installation

Internal Connecting Wires shall connect the exposed face of a cell to the opposite side of the

cell. An exposed face is any side of a gabion cell that will remain exposed or unsupported

after the structure is completed. Lacing wire or prefabricated internal connecting wires shall

be used as internal connecting wires.

16.3.4.1 1meter High Gabions

1meter high gabions shall be filled in three layers, 300 mm at a time. Connecting wires

shall be installed after the placement of each layer, that is, at 300 mm high.

16.3.4.2 0.5m High Gabions

0.5 meter high gabions do not require connecting wires unless the baskets are used

to build vertical structures. These units shall be filled in two layers 250mm at a time.

Connecting wires shall be installed after the placement of the first layer, which is at 250mm

high.

16.3.5 Lid Closing

Once the gabion baskets are completely full, the lids will be pulled tight until the lid meets

the perimeter edges of the basket. The lid must then be tightly laced and/or fastened along

all edges, ends and tops of diaphragm(s) in the same manner as described in earlier sections.


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16.3.6 Mesh cutting and folding

Where shown on the drawings or otherwise directed by the engineer, the gabions shall be

cut, folded and fastened together to suit existing site conditions. The mesh must be cleanly

cut and surplus mesh either folded back or overlapped so that it can be securely fastened

together with lacing wire or fasteners in the manner described in earlier Section. Any

reshaped gabions shall be assembled, installed, filled and closed as specified in the previous

sections.

16.4 Method of Measurement

The payment quantities for excavation shall be determined by the outside limits of the

gabion structure. Quantities will be determined from cross sections and the linear distance,

and paid for under the appropriate bid items.

The quantity to be paid for “In place gabions” shall be the number of gabions of respective

sizes. Project conditions and material availability will determine the actual size of gabions to

be used.

Excavated material beyond the limits of the gabions shall be backfilled with gravel, crushed

rock or other material approved by the engineer.

16.5 Basis of Payment

Accepted gabions will be paid for at the unit price for each pay item included in the

contract.

16.6 Testing and Acceptance criteria

The material should get approval from the Consultant/ Purchaser before the actual supply

start. The manufacturer of the Gabion facing unit should provide “Manufacturers Test

Certificate’ and Quality Conformity Certificate for the material with every lot/shipment.

Tensile strength test and zinc coating test on basic wire shall be done on one sample per


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every 10,000 numbers of units supplied. Before approval of the material at least one sample

shall be got tested from Indian Institute of Technology, Roorkee in the presence of the

consultant/ Purchaser.

PVC Coating Thickness: The thickness of the PVC coating shall be determined on a randomly

chosen individual piece of wire removed from the coil at 3 places 1 metre apart.

Measure with a micrometer the diameter of the galvanized steel wire with PVC coating.

Determine the thickness of the PVC coating by stripping the PVC coating from the wire and

measure the reduced diameter with a micrometer. The thickness of the coating is the

difference between the diameter of the galvanized steel wire with PVC coating and the

measured diameter of the galvanized steel wire divided by two. The thickness values should

be as per clause 1.2.4. While removing the PVC coating by stripping, take care not to remove

any of the metallic surfaces.

16.6.1 Selvedge strength test:

i. A tensile test on mesh sample shall be carried out in order to estimate selvedge

strength test. The test shall be carried out as per procedure outlined below. The

selvedge strength shall be minimum 25 kN/m.

ii. Take a DT mesh of approximately 1.0 m width.

iii. The height of the sample shall be such that after selvedging on both the sides (1m),

there shall be at least two mesh repetitions between the two selvedged wires, so

that effective height of the sample shall be more than 300 mm.

iv. Sample shall be loaded on the UTM in a direction parallel to twist, with the samples

being gripped at the two selvedged wires & not mesh twist.

vi. The distance between the two selvedge wires shall be recorded as Initial gauge

length.


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Distance between the two end gripping points (pins) along the width of the sample shall be

recorded as the unit width under test. The width shall be at least 700 mm. The load shall be

applied gradually to the sample and the test be continued till the break point.

The peak load and the % elongation shall be recorded.

The strength of the selvedge connection shall be (peak load/unit width under test) expressed

in kN/m.

NB. If the sample slips at any of the gripping point during the test, such a test shall be

discarded and a new sample shall be taken.

16.6.2 Eligibility of Manufacturer:

Manufacturer of woven steel wire double twist hexagonal mesh gabions shall have:

• In-house facility to test the tensile strength of the basic GI wire and Mesh Panels using

computerized testing facilities which forms mechanically woven double twisted mesh

panels

• In-house test facility for zinc coating test.

• A valid ISO 9001:2008 accreditation from an internationally accredited organization

such as Lloyd’s Register for its Gabion manufacturing facilities.

• Manufacturing experience of mechanically woven Gabions of minimum 7 years

internationally or in India as per International standards.

• The Manufacturer / Supplier shall have existence in India for more than 7 years from

the date of this tender notice.

• Manufacturer of woven double twist hexagonal steel wire mesh gabions shall have

proven experience in supply and designing of retention works in India for at least7

years.

• Experience of supplying minimum 20,000 cum of Gabions. Supplier shall provide

performance certificate of material supplied to government department/Public sector

undertaking.

The Manufacturer / Supplier should not have a history of poor performance such as

abandoning the works, financial failures, blacklisting. If it is observed, Manufacturer /

Supplier will be automatically disqualified.


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17 Providing and placing stones in Gabions:

17.1 Material Rock:

Rock for the Gabion facia shall be hard, angular to round, durable and of such quality that

they shall not disintegrate on exposure to water or weathering during the life of the

structure. The rocks shall range between 150 mm to 250 mm for 10x12 type mesh. Each

range of sizes may allow for a variation of 5% oversize rock by number of particles, or 5%

undersize rock by number of particles, or both. The size of any oversize rock shall allow for

the placement of minimum of three layers of rock must be achieved when filling the 1 m high

units and a minimum of two layers for the 0.50 m high units. Suitable coal pick stone (reject

coal boulders) available in RGTPP, Khedar, Hisar Thermal Plant area shall be used as rock

for gabion wall. The coal pick stone shall be issued free of cost to the contractor on ‘as is

where is’ basis and contractor shall arrange for breaking them further in the require sizes.

Loading, Unloading, handling and transportation of the same from Power Plant to work site

shall be at contractors own cost and deemed to be covered in his quoted unit rate.

17.2 Placement of stones in GabionFacia Section.

The facing section shall be filled with rock in a careful way to get good horizontal and vertical

alignment. During the filling operation skilled manual stone placement is required to

minimize voids. The maximum permitted porosity of stone filling shall be 40%. For vertical or

near vertical structures the exterior of the basket may be carefully hand placed to give a

neat, flat, and compact appearance. Care shall be taken when placing fill material to ensure

that the sheathing on the PVC coated baskets is not damaged. The facing stones should

orient in such a way to get their flat surfaces facing to the front.

The cells shall be filled in stages so that local deformation may be avoided. At no time shall

any cell be filled to a depth exceeding 0.30 m higher than the adjoining cell. It is also

recommended to slightly overfill the baskets by 25mm to 50 mm to allow for settlement of

the rock

Internal Connecting Wires with lacing wire shall connect the exposed face of a cell to the

opposite side of the cell. Internal Connecting performed stiffeners shall connect the exposed

face of a cell to the adjacent side of the cell. Preformed stiffeners are installed at 45° to the


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face (side of the unit), extending an equal distance along each side to be braced

(approximately 300 mm). An exposed face is any side of Gabion facia and tail with double

twist hexagonal mesh units that will be exposed or unsupported after the structure is

completed.

17.3 Method of Measurement:

Measurement shall be in volume from cross sections and longitudinal sections.

17.4 Basis of Payment:

Payment should be per unit of cubic meter.

17.5 Acceptance:

The size of the stone for filling in 10x12 mesh shall be 150 mm-250mm.

17.5.1.1 Non woven filter media- Geotextile behind gabion walls / around perforated

pipes and around sand chimeny filter:

18. Material

The nonwoven thermally bonded or needle punched or any equivalent geotextile shall

be used. The geo-textile shall be made of polyethylene or Polypropylene or polyester or

similar fibers manufactured through machine made process of heat bonding or needle

punching techniques. The mean Values of Geo-textile shall be as shown in table 4.

Table 4

PROPERTIES: Mean Values Tolerance Test Method

Mechanical:

Wide Width strip tensile 22 kN/m - 0.75 kN/m EN ISO 10319

Elongation 32%

± 5%

EN ISO 10319

CBR Puncture resistance

4300

-150 N EN ISO 12236


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Hydraulic:

Apparent Opening Size,

AOS90 85 micron + 50 microns EN ISO 12956

Permeability, VI H=50mm 45 l/m2.sec - 30 l/m2.sec EN ISO 11058

Physical:

Mass per Unit Area 335 `g/sq.m

± 10 g/sqm

Composition:

About 70% polypropylene and rest shall be polyethylene or any other equivalent

material.

1 Method of measurement :

Quantity of filter geotextile shall be determined from cross sections and the linear

distance, and paid for under the appropriate bid items.

2 Basis of Payment :

Accepted filter geotextile shall be paid for at the unit price (per square metre area) for each

pay item included in the contract.

3 Method of Testing:

The supplier has to submit a Quality conformity certificate and Manufactures test certificate

for the parameters indicated in table 3 for every lot/shipment.Before approval of the

material by the consultant/ Purchaser at least one sample shall be got tested from IIT

Roorkee in the presence of the consultant/ Purchaser.


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19 High strength Geogrid as basal reinforcement:

19.1 Description:

This work shall consist of furnishing and placing uniaxial high strength geogrid or approved

equivalent Geogrid over a soft foundation soil to construct an embankment over it. This

geogrid layer acts as a reinforcement layer between soft soil and embankment fill soil.

19.2 Materials:

High strength geogrids, with low creep characteristics and stress-strain characteristics to

mobilize the desired tension at 5% strain shall be used the geogrids may be made from

Polyester (PET). The geogrids shall have on outer protective coating of low density

polyethylene sheath. The tensile strength of geogrid at 5% strain shall not be less than 250

kN/m, which value is the required tensile strength of the reinforcing geogrid, shall be on

basis of long term design strength value of the particular grade of geogrid proposed. The

long term design strength shall be obtained by reducing the short term or ultimate tensile

strength by the reduction factors as specified in BS 8006-1995. viz. reduction factor for

creep, mechanical damage, environmental damage and extrapolation of data.

19.3 Acceptance ofGeogrids:

Geogrids specified as reinforcement in the basal mattress for ground improvement are high

strength geogrids. These have to develop the requisite design tensile strength at less than

5% strain on long term strength basis. Geogrids made from polyester (PET) or Polyvinyl

Alcohol (PVA / PA) are recommended because they have superior stress – strain and creep

properties. The manufacturer shall provide the following data and certificates:

Note:At least one sample shall be got tested from IIT Roorkee in the presence of the

consultant/ Purchaser and only then approval shall be accorded by the purchaser.

19.3.1 Partial material factors as per BS 8006:1995;

Partial reduction factors of creep of 120 years design life as well as of shorter durations.

Partial reduction factors of mechanical damage.

Partial reduction factors of environmental effects.

Partial material factors to extrapolate the data

19.3.2 Stress strain curves of different loading durations.


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19.3.3 The manufacturer shall provide BBA certificate to use the geogrids as reinforcing

geogrids.

19.3.4 The manufacturer shall provide ISO: 9002 certificate of manufacturing process.

19.3.5 The manufacturer/ supplier shall have experience to use in similar ground

improvement projects in India and/ or abroad geogrids of the type he proposes to

use in the project. He shall provide proof of the same, by providing adequate

information concerning such projects. Geogrids shall not be accepted in the absence

of such information

19.4 Geogrid shall be supplied in roll length of not less than 100m and roll width not

less than 4.5m.

Note:Uncertified geogrids whose quality and stress – strain properties are not established shall not

be accepted. Use of lower quality geogrids may result to higher strains in the geogrids such

as over – stress may even lead to the rupture of geogrids and instability of the earth

structure.

Quality ofgeogrids is very important in this application, as

I. The geogrid may be subjected certain amount unanticipated strains due to local settlements of

clay in some places.

II. The geogrids used in the basal mattress would be under water table for most part of the year

and the water is likely to be having some salts etc. Over a period of years, the salts may act

to reduce the strength of the geogrids. Hence adequate partial reduction factor against

environmental damage has to be used.

19.5 Eligibility Criteria for Manufacturer:

The manufacturing unit of geogrid should have ISO 9001:2008 accreditation from an

internationally accredited organization such as Lloyd’s Register or equivalent certification for

its quality procedures. In-house facility to test the tensile strength of the geogrid using

computerized testing facilities.


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19.6 Delivery and Storage:

Each roll delivered to site shall be clearly labeled with grade, batch number and wrapped in

material that will protect the geogrid including the ends of rolls from damage due to

shipment, water, sunlight and contaminants. The protective wrapping shall be maintained

during shipment and storage.

19.7 Equipment:

All equipment necessary for the placing of the geogrid shall be approved before work will be

permitted to begin.

19.8 Construction Requirements:

19.8.1 Geogrid packaging and storing – During storage, geogrid rolls shall be elevated off the

ground and adequately covered to protect them from site construction damage,

precipitation, extended ultraviolet radiation including sunlight, chemicals that are strong

acids or strong bases, flames including welding sparks, and any other environmental

condition that may damage the physical property values of the geogrid.

19.8.2 Site preparation – The top foundation soil shall be free from undulations and

prepared to the level as indicated in the construction drawings or as directed by the

Engineer.

19.8.3 Installation – The geogrid shall be laid at the proper elevation and alignment as shown on

the construction drawings. It shall be placed with main strength direction oriented

perpendicular to centerline of the embankment.

The geogrid shall be installed in accordance with the installation guidelines provided by the

manufacturer or as directed by the Engineer. It may be temporarily secured in place with

ties, staples, pins, sand bags as required by fill properties, fill placement procedures or

weather conditions or as directed by the Engineer.

19.8.4 Joints, and overlaps – An overlap of 300 mm or as indicated by Engineer shall be

provided between the adjacent rolls. There shall be no joints along the length ofgeogrid.

19.9 Method of Measurement:

The Geogrid shall be measured by the square meter or fraction thereof in place. Excavation,


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backfill, bedding and cover material are separate pay items.

19.10Basis of Payment:

Unless otherwise noted in the Plans, the accepted quantity of Geogrid complete in place

shall be paid for at the contract unit price per square meter. This price shall constitute full

compensation for all work materials, labor and other incidentals required to complete the

work in accordance with these Specifications.

20.0 Turfing with jute geo textile and planting of approved species:

Jute geo textile 500 GSM with aperture size100mmx100mm shall be laid on the

downstream slopes of ash dyke. Jute geo textile to be held in position by wooden pegsat 3

meter centre to center followed by providing and spreading, planting of approved species,

watering etc. complete till the plants establishes itself uniformly. The rate shall include the

cost of all materials; watering charges and maintenance for one year. Constant watch shall

be maintained to ensure that dead patches are replanted and undesirable growth such as

weeds, rhizomes and tubes are weeded out.

20.1 Measurement & Payment:Length and breadth shall be measured in meters correct to the

second place of decimal. The area of the turfing shall be measured for payment in sq.m.

correct to the second place of decimal.

21.0 Brick Masonry Works:

21.1 Scope:

This section covers the furnishing of all labour, materials and equipments and performing of

all operations required for the supply of materials and erection work and incidental items

pertinent thereto in drains, road curbs etc. all in accordance with the drawings and these

specifications.

21.2 General requirements:

21.2.1 Masonry products such as face bricks, common bricks and tiles shall be products of

producers or suppliers approved by the Engineer.


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21.2.2 Delivery, storage and handling of Materials shall be as follows:

(i) All materials shall be delivered to the site, stored and handled so as to prevent

inclusion of foreign substances, damage by breakage, exposure to the weather and

contact with the soil.

(ii) Cementatious materials shall be delivered in unbroken containers or packages and

stored in weatherproof enclosures.

21.3 Materials:

21.3.1 Cement shall be ordinary Portland cement of 43-Grade conforming to IS: 269 and IS: 8112 or

any other type approved by the Purchaser.

21.3.2 Water for mortar shall be clean and potable and free of salts, iron and injurious amounts of

organic matter.

21.3.3 Sand shall conform to the requirements of IS -2116 (Latest edition)

21.3.4 Fly Ash Bricks conforming to relevant IS Code only shall be used. In case of non-availability of

Fly Ash Bricks, common clay bricks may be used with the written approval of Engineer-in-

Charge. Common burnt clay bricks and face bricks shall conform to the requirements of IS:

1077 and shall be of uniform colour, strength and size. Bricks shall not absorb more than

20% of their own dry weight when soaked in water.

21.3.5 Crushing strength bricks shall not be less than 100 kg/sq.cm

21.3.6 Wall ties shall be 6mm mild steel "U" or "Z" shaped 50mm less in depth than the width of

the wall into which they are built, spaced 400mm centers vertically or provided at every fifth

course.

21.3.7 Reinforcement for masonry walls wherever required shall be of mild steel 8mm diameter tor

steel bars welded/tied to the wall ties at every fifth course of brickwork.

21.3.8 Samples of all materials shall be submitted for the approval of the Engineer.

21.3.9 Mortar of specified proportions as shown in the construction drawings shall be mixed by

volume with just enough water added to produce a workable mixture. Only freshly prepared

mortar shall be used. Mortar shall conform the requirements of IS: 1925.

21.4 Bond & Coursing:

21.4.1 All masonry walls shall be laid with horizontal courses level and true in English bond. All

masonry units shall be laid up in full beds of mortar with all units butted solidly against

adjacent units with mortar in between.


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21.4.2 All masonry units having appreciable water absorption potential shall be soaked as per

relevant IS code.

21.4.3 Vertical surfaces of all masonry walls and partitions shall be plumb and true to line on

uneven surface with maximum total variation of 25mm in any plane or 12.5 mm in 5 meters.

21.4.4 Where two walls meet or intersect, the masonry course shall be carried up together,

bonding at least fifty percent of the units at the intersection.

21.4.5 Horizontal surfaces of masonry not being worked on shall be protected from the natural

elements by the use of non-staining waterproof coverings, properly secured in place.

21.4.6 Brick tiles where shown in drawings shall be laid with staggered vertical joints and shall be

bonded to the brick walls.

21.4.7 Masonry in contact with structural steel including beams and columns shall be anchored to

the steel works as indicated in the drawings.

21.5 Masonry joints:

21.5.1 All joints in masonry wall surfaces to receive cement plaster shall be raked out to a depth of

12mm to create mechanical bond for the plaster finish.

21.5.2 Joints in exterior walls to be left exposed shall be neatly tooled with a weathered joint.

21.5.3 Where masonry shuts penetrating built-in-terms such as doors frames etc. the joints shall be

6mm wide and raked to a depth of 20mm for subsequent caulking.

21.5.4 Where openings are left in masonry fixing doors, windows etc. or where masonry is

discontinued for extending at a later date, the masonry work should be left at an angle not

steeper than 60 degree.

21.6 Cleaning:

21.6.1 All exposed brickwork shall be scrubbed down with clean water and rinsed thoroughly.

21.6.2 All work stained or discolored during the process of cleaning shall be replaced by the

Contractor at his own expenses.

21.6.3 Green work shall be protected from the effects of sun, rain etc. by suitable covering. All the

masonry work shall be kept constantly moist on the faces for a period of seven days.


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21.6.4 The contractor shall carry out all scaffolding and planking necessary for efficient execution of

work at all levels. The scaffolding and planking shall be of the best material and the

contractor shall be responsible to ensure safety of personnel working on them at all levels.

21.6.5 At the end of construction, the contractor shall ensure proper plugging of all openings made

for supporting the scaffolding.

21.7 Measurement & Payment.

The length, height and thickness of Brick Masonry work shall be measured in meter correct

to third place of decimal. The thickness of wall shall be measured excluding the thickness of

plaster. Only specified dimension shall be owed, anything extra shall be ignored. The

quantity shall be calculated in cubic meter nearest to third place of decimal. No deduction

shall be made nor extra payment made for making grooves and weep holes in masonry. The

cost of testing of all materials shall be borne by the contractor and no separate payment

shall be made on account of this.

22.0 Dry Brick Pitching:

22.1 Burnt clay bricks, for U/s slopping portion shall be conforming to IS: 1077 (latest). Fly ash

lime brick and clay – fly ash bricks shall conform to IS: 12894 (latest) and IS: 13757(latest)

respectively. The class of bricks shall be a minimum of class-10. The ash brick’ conforming to

relevant IS codes only shall be used. In case of non- availability of fly ash bricks within a lead

of 100 km, common clay bricks may be used with the written permission of Engineer-in-

charge.

22.2 Bricks for construction work shall be hand/machine made, well burnt of uniform size, shape,

edges and uniform cherry red colour. Bricks shall give a clear ringing sound when struck and

have a minimum crushing strength of 10 N/sq. mm unless specified in the item. The average

water absorption shall not be more than 20 percent by weight up to class 12.5 and 15

percent by weight for higher classes. Bricks, which do not conform to this requirement, shall

be rejected. Over or under burnt bricks are not acceptable for use in the works. Sample of

bricks shall be submitted to the Engineer-in- Charge for approval and bricks supplied shall

conform to approved samples. If demanded by Engineer brick samples shall be got tested as

per IS: 3495 by Contractor in any laboratory approved by the Engineer at no extra cost to

purchaser. Bricks rejected by Engineer shall be removed from the site of works within 24

hours.


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22.3 The size of bricks used shall be either modular size as per IS: 1077 (latest edition) and IS:

12894 (latest edition) or locally available conventional size as approved by Engineer-in-

Charge. The nominal size of the modular brick shall be 200mm x 100mm x 100mm with the

permissible tolerances over the actual size of 190mm x 90mm x 90mm as per IS: 1077. The

nominal thickness of one brick and half brick walls using modular bricks shall be considered

as 200mm and 100mm respectively. In the event of use of traditional bricks of nominal size

230mm x 115mm x 75mm with tolerance up to 13mm in each dimension, one brick and half

brick walls shall be considered as 230mm and 115mm respectively.

22.4 Each bricks shall have the manufactures identification marks clearly marked on the frog. Clay

and fly ash brick not found upto the satisfaction of the Engineer-in-Charge shall be removed

immediately from site by the contractor.

22.5 Fly Ash Lime Bricks for pitching work shall be laid inside the 3 M X 3 M grid made of brick

masonry panels of size as shown in the construction drawing and shall be bonded inside the

impervious layer. For specification of brick masonry refer to respective clause.

22.6 Measurement & Payment:

The Length and breadth for pitching shall be measured in meters correct up to second place

of decimal. The measurement for payment of dry brick pitching shall be done in sq.m.

correct up to second place of decimal. The measurement and payment of brick masonry

work shall be as per respective clause.

23.0 Dismantling Work:

23.1 The dismantling implies, carefully taking up or down and removing without damage. This

shall consist of dismantling the plain/ reinforced cement concrete, Rock toe etc as per

drawing and the direction of the Engineer-in-Charge.

23.2 Measurement & Payment:

The Length, width and thickness shall be measured in meters correct up to third place of

decimal. The measurement for payment of dismantling concrete/Rock toe shall be done in

cu.m. correct up to the second place of decimal.


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24.0 Cement Concrete:

24.1 Scope

24.1.1 This specification deals with Cement Concrete, plain or reinforced for general use, and

covers the requirements for concrete materials, their storage, grading, mix design, strength

and quality requirements, pouring at all levels, reinforcements, protection, curing, form

work, finishing, painting, admixtures, inserts and other miscellaneous works.

24.1.2 The provision of the latest revision of IS: 456 shall be complied with unless permitted

otherwise and any other Indian Standard Code (latest revision) shall form a part of this

specification to the extent that it has been referred to or applicable within this specification.

This specification shall have precedence in case anything contrary to this is stated anywhere

in this bidding document.

24.2 General requirements:

(a) The contractor shall furnish all labour, materials and equipment to mix, place and

finishing all concrete complete, as indicated on the construction drawings and as

directed by Engineer-in-Charge.

(b) All materials, tests, mixing, placing, formwork shall conform to the code of practice

for plan concrete IS: 456 (latest edition).

(c) Ordinary port-land cement shall be of 33 Grade or 43 Grade conforming to IS: 269

(latest edition) and IS: 8112 (latest edition) respectively or Portland Pozzolana

Cement conforming to IS: 1489 or any other type as approved by the Purchaser

(d) Concrete aggregates shall conform IS: 383 (latest edition).

(e) Water used in mixing concrete shall be clean and free from injurious amount of oils,

acid, alkalis, organic materials or other deleterious substances.

24.3 Materials:

24.3.1 Cement:

Cement used shall be Ordinary Portland Cement of 43-Grade conforming to IS: 269 and IS:

8112 respectively or Portland Pozzolana Cement conforming to IS: 1489 or any other type as


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approved by the Purchaser. Rapid hardening Portland cement can be used under special

circumstances, if permitted by the Engineer -in-Charge.

The cement to be used shall be of the repute brand such as (i) Ambuja Cement (ii) L & T; (iii)

J. K. Laxmi Cement; (iv) Shree Cement; (v) Aditya Birla. Cement,(vi) ACC.

24.3.2 Aggregates:

All aggregates shall conform to the provisions and tests methods of IS: 383 (latest revision)

and/or IS: 515 (latest revision). Samples of aggregates proposed to be used shall be

submitted free of charge in sufficient quantities to the Engineer-in-Charge with sieve analysis

data for his approval. He will preserve approved samples for his future reference. This

approval will not in any way relieve the contractor of his responsibility of producing concrete

of specified qualities.

24.3.4 Coarse Aggregates:

The maximum size of coarse aggregate shall be as follows:

For thin RCC members with very narrow shape : 12mm

For Reinforced Concrete including foundations : 20mm

For ordinary Plain Concrete : 20mm

For Lean Concrete : 40mm (max.)

Grading of coarse aggregates for a particular size shall generally conform to relevant IS

codes and shall also be such as to produce a dense concrete of the specified proportions

and/or strength and consistency that will work readily into position without segregation.

24.3.5 Fine aggregates (Sand):

Coarse and fine sand shall be well graded within the limits by weight as specified in IS: 383

(latest revision). Fineness modulus shall not vary by more than plus or minus 0.20 from that

of the approved sample. Fineness modulus for sand should not be less than 2.25. Washing

of aggregates by approved means shall be carried out, if desired by the Engineer at no extra

cost to the Purchaser.


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24.3.6 Water:

Water shall be clean, fresh and free from organic or other deleterious matters in solution or

in suspension in such amounts that may impair the strength or durability of the concrete.

Potable water is generally satisfactory and shall conform to the requirements of IS: 456-2000.

IS: 3025 and 3550 may be followed for testing, if required.

24.3.7 Admixtures:

The use of admixtures in concrete for promoting workability, improving strength, entraining

air or for any other purpose may be used only with the approval of the Engineer-in-Charge.

Addition of admixture should not reduce the specified strength of concrete in any case.

24.3.8 Reinforcement:

(a)Reinforcing steel shall be clean and free from loose mill scales, dust, loose rust and coats

of paints, oil, grease or other coating, which may impair or reduce bond. It shall conform

to the following IS specifications:

i) Mild steel & medium tensile steel bars and hard drawn steel wire conforming to

Grade-I IS: 432

ii) High strength deformed steel bars conforming to IS: 1786

iii) Structural steel conforming to Gr. A of IS: 2062

iv) Thermo- mechanically treated bars (TMT Bars):

Reinforcement and structural steel of the main producers e.g. SAIL, TISCO and

Rastriya Ispat Nigam Ltd. shall only be used.

(b) All steel reinforcements, including and above 6mm diameter shall necessarily be of

tested quality.

(c) The contractor shall furnish reinforcement accessories. Binding wire shall be annealed

iron wire quality not less than No. 16 SWG (1.65mm dia).

(d) Bar supports, chairs and bolsters (as approved by Engineer) shall be sufficiently strong to

support the steel properly.


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24.4 Formwork:

Formwork shall be composed of steel and/or best quality shuttering wood of non-absorbent

type. Timber shall be free from knots and shall be of medium grain as far as possible. Hard

woods shall be used as caps and wedges under or over posts. Plywood or equivalent shall be

used where specified to obtain smooth surfaces for exposed concrete work. Struts shall

generally be mild tubes and strong sal-ballahs 150mm in diameter or above. Bamboos, small

diameter ballahs etc. shall not be used unless approved by the Engineer-in-Charge in specified

cases.

24.5 Storage of Materials:

24.5.1 Storage of materials shall be as described in IS: 4082. All materials shall be so stored as to

prevent deterioration or intrusion of foreign matter and to ensure the preservation of their

quality and fitness for the work. Any material which has deteriorated or has been damaged

or as otherwise considered defective by the Engineer-in-Charge shall not be used and shall

be removed from site immediately falling which, the Engineer shall be at liberty to get the

materials removed and the cost of there of shall be realized from the contractors dues. The

contractor shall maintain up to date accounts of receipt issue and balance (stock wise) of all

materials.

24.5.2 General storage shall be carried out by the Contractor in a manner affording convenient

access for identification and inspection of all items. The storage facilities shall be subject to

approval of the Engineer-in-Charge.

24.5.3 Cement (to be furnished by the Contractor) shall be stored by Contractor in silos or suitable

weather proof, properly ventilated buildings with dry floors in a manner to prevent

deterioration. Cement held in storage for a period of 90 days or longer shall be tested at an

approved laboratory before being put to use.

24.5.4 Aggregates shall be stored by the Contractor in areas floored with tightly laid wooden planks

or other approved hard, smooth and clean surface, in a manner precluding intrusion of

foreign materials. Aggregate of different classes shall be stored in separate piles sufficiently

away from each other to prevent the material of edges of piles from getting inter-mixed.

24.5.5 Reinforcement shall be stored off the ground in a manner to prevent objectionable changes

in original surface characteristics, in separate piles or racks above grade.


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24.6 Grade of Concrete:

24.6.1 General:

Concrete shall be either nominal mix or design mix and in grades designated as M-15 and M-

20 etc. as specified in IS: 456-2000. In case of liquid retaining structures, IS: 3370 (latest) will

be followed. Lean concrete shall be of nominal mix 1:3:6 (M-10) with aggregate of nominal

size 40mm maximum or as indicated in drawings.

24.6.2 Nominal Mix Concrete:

Nominal mix concrete is recommended only when accurate control is impracticable and not

necessary. However, if nominal mix concrete is allowed by the Engineer-in-Charge, it shall

be used for the concrete upto the grade of M15. Nominal mix concrete does not require

preparation of trial mixes.

24.6.3 In general, concrete mix may be used for concrete of M15 or lower. The proportion of

materials for nominal mix concrete shall be as per IS: 456-2000.

24.6.4 If nominal mix concrete made in accordance with the proportions given in IS: 456-2000 for a

particular grade does not yield the specified strength and fails to satisfy the requirements of

"Acceptance criteria for concrete" as specified in IS: 456, (latest edition) the cement content

shall be increased as directed by the Engineer to obtain a specified strength at no extra cost

to the Purchaser. This richer mix shall continue until the Engineer instructs otherwise.

24.6.5 Nominal mix concrete proportion of a given grade specified under relevant para above shall

not however be classified as a higher grade on the ground that the test strengths were found

higher than the minimum specified.

24.7 Design Mix Concrete:

24.7.1 This concrete shall be used on all concrete works, except where specified otherwise. Design

mix concrete for use in plain and reinforced concrete structures shall be in grade M-15, M-20

and above, with minimum cement content and maximum water cement ratio shall be

decided as per IS 456 based on type of exposure. The type of exposure shall be considered

not less than moderate.

24.7.2 The mix proportions for all grades of concrete shall be designed to obtain strengths

corresponding to the values specified hereinafter for respective grades of concrete.


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Preliminary tests as specified in the IS code and required by the Engineer-in-Charge shall be

carried out sufficiently ahead of the actual commencement of the work with different grades

of concrete made from representative samples of aggregates and cement expected to be

used on the job to ascertain the ratios by weight of cement to total quantity of fine and

coarse aggregates and the water cement ratio required to produce a concrete of specified

strength and desired workability.

24.7.3As a guide to perform the mix design properly, the relationship between water/cement ratio,

aggregate to cement ratio, workability and strength of concrete are furnished in Table-1 &

Table –2.


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TABLE -1 (FOR GUIDANCE ONLY)

MIX PROPORTIONS (BY WEIGHT) EXPECTED TO GIVE DIFFERENT DEGREES OF WORKABILITY WITH

DIFFERENT WATER CEMENT RATIOS AND A SPECIFIED STRENGTH

Workability Water/cement Ratio

Compressive strength in cube in 28 days (N/mm2)

Ratio by weight of cement to gravel aggregate

Ratio by weight of cement to crushed stone aggregate

20mm 40m 20mm 40mm

1. 2. 3. 4. 5. 6. 7.

Very

Low

Slump

(0-25 mm)

0.4

0.5

0.6

0.7

45

36

27

20

4.8

7.2

8.5

9.0

5.3

7.7

8.6

9.0

4.5

6.5

7.8

8.7

5.0

7.4

8.4

8.9

Very

Low

Slump

(25-50 mm)

0.4

0.5

0.6

0.7

45

36

27

20

3.0

5.5

6.8

8.0

4.5

6.7

7.1

8.5

3.5

5.0

6.3

7.4

4.0

5.5

7.0

8.0

Medium

Slump

(50-100 mm)

0.4

0.5

0.6

0.7

45

36

27

20

3.5

4.8

6.0

6.8

3.8

5.7

7.3

7.0

3.1

4.2

5.2

6.2

5.6

5.0

6.2

7.0


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TABLE-2 (FOR GUIDANCE ONLY)

GRADES OF CONCRETE AND COMPRESSIVE STRENGTH

Grade of

concrete

Preliminary test

at 28 days

Work Test

At 7 days At 28 days

M-15 20 N/mm2

(204 kg/cm2)

10 N/mm2

(102 kg/cm2)

15 N/mm2

(103 kg/cm2)

M-20 26 N/mm2

(265 kg/cm2)

13.5 N/mm2

(138 kg/cm2)

20 N/mm2

(204 kg/cm2)

M-25 32 N/mm2

(326 kg/cm2)

18.5 N/mm2

(189 kg/cm2)

25 N/mm2

(255 Kg/cm2)

M-30 38 N/mm2

(387 Kg/cm2)

20 N/mm2

(204 Kg/cm2)

30 N/mm2

(306 Kg/cm2)

24.7.4 Maximum/Minimum Cement Content: -Cement content not including fly ash and ground

granulated blast furnace slag in excess of 450 kg/m3 should be used unless special

consideration has been given in design to increased risk of cracking due to drying shrinkage.

The minimum cement content, maximum water cement ratio and minimum grade of

concrete for different exposures with normal weight aggregates of 20mm nominal maximum

size shall be as prescribed below:


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Exposure Plain Concrete Reinforced Concrete Minimum Grade of

Concrete

Minimum

Cements

kg/m3

Maximum

Free W/C

Minimum

Cements

kg/m3

Maximum

Free W/C

Plain

Concrete

Reinforced

Concrete

Mild 220 0.60 300 0.55 - M20

Moderate 240 0.60 300 0.50 M15 M25

Severe 250 0.50 320 0.45 M20 M30

Very Severe 260 0.45 340 0.45 M20 M35

Extreme 280 0.40 360 0.40 M25 M40

The mix proportion for all grades of concrete shall be designed to obtained strength

corresponding to the values specified herein for respective grade of concrete. Preliminary

tests as specified in IS code and required by the Engineer-in-charge shall be carried out

sufficiently ahead of the actual commencement of the work with different grades of

concrete made from respective samples of aggregates and cement expected to be used on

the job to ascertain the ratio by weight of cement to total quantity of fine and coarse

aggregate and the water cement ratio required to produce a concrete of specified strength

and desired workability.


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TABLE -3

GRADE OF CONCRETE AND COMPERESIVE STRENTH AT 28 DAYS

Specified

grade

Mean of group of 4 non-overlapping

consecutive test results in N/mm2.

Individual test results

N/ mm2

M-15 >fck + 0.825 x established standard

deviation

or

fck + 3 N/mm2 , whichever is greater

>fck -3 N/mm2

M-20 or

above.

>fck + 0.825 x established standard

deviation

or

fck + 4 N/mm2 , whichever is greater

>fck- 4 N/mm2

24.7.5 The mix design shall be got done by the contractor from the reputed Institute and for

obtaining the ultimate compressive strength as given in Table-3 and the cost of mix design

& testing shall be borne by him or existing design mix can be used with the permission of

En-In-Charge. The test reports shall be submitted to the Engineer-in-Charge. On the basis

of the preliminary test reports for trial mix, a proportion of mix by weight of sand, water

cement ratio will be approved by the Engineer-in-Charge, which will be expected to give

the required strength, consistency and workability and the proportions so decided for

different grades of concrete shall be adhered to during all concreting operations. If

however, at any time the Engineer feels that the quality of materials being used has

changed from those used for preliminary mix design, the Contractor shall have to run

similar trial mixes to ascertain the mix proportions and consistency. It will be within the

competency of the Engineer-in-Charge to reduce the number of trial batches and then

number of test specimens mentioned above. Further, the Engineer-in-Charge can also

allow adoption of the mixes already tried and found satisfactory with similar materials, for


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other jobs at the same site, without any fresh design of mix. Nothing extra shall be paid for

use of cement in excess of the minimum quantity specified above for achieving the

required strength as per design mix for various grades of concrete even though the design

mix is approved by the Engineer-in Charge.

24.7.6 In designing, the mixes once approved must not be varied without prior approval of the

Engineer. Should, however, the Contractor anticipate any change in the quality of future

supply of materials than that has been used for preliminary mix design, he shall inform the

same to the Engineer and bring fresh samples sufficiently ahead to carry out fresh trial

mixes. The Engineer-in-Charge shall have access at all places and laboratory where design

mix is prepared.

24.7.7 Design mix will indicate the extent of variation in grade of aggregate, which can be allowed

by means of graphs and curves etc.

24.7.8 In designing, the mix proportions of concrete, the quantity of both cement and aggregate

shall be determined by weight. The Engineer-in-Charge may allow the quantity of

aggregate to be determined by equivalent volume basis after the relationship between the

weight and volume is well established by trial and the same shall be calibrated in tanks or

weighed. All measuring equipment shall be maintained in a clean and serviceable

condition, and their accuracy periodically checked.

24.7.9 To keep the water cement ratio to the designed value, allowance shall be made for the

moisture contents in both fine and coarse aggregates and determination of the same shall

be made as frequently as directed by the Engineer. The determination of moisture

contents shall be according to IS: 2386 (Part-III) (Latest edition).

24.8 Mixing and placing of concrete:

24.8.1 General:

Concrete shall not be placed in any unit of the work until after the forms, bracing, reinforcing

steel and other preparations for casting have been approved by the Engineer-in-Charge and

approval given to proceed with the casting.

24.8.1 Supervision:

No concrete shall be placed except in the presence of the Engineer-in-Charge or his

authorized representative. Concrete which is not placed in accordance with the


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specifications or which is of inferior quality as determined by the Engineer-in-Charge shall be

removed and replaced by the Contractor without any extra cost to the owner.

24.8.3 Mixing:

All concrete shall be mixed until there is a uniform distribution of materials and shall be

discharged completely before the mixer is recharged. Mixing shall be done in a mechanical

mixer and the type and size shall be subject to the approval of the Engineer-in-Charge. The

mixer shall be rotated at a speed recommended by the manufacturer and mixing shall be

continued for at least two minutes after all materials are in the drum. For batches larger

than 0.75 cum. mixing time shall be increased by 15 seconds for each additional 0.75 cum. or

fraction thereof. All concrete shall be discharged within 3 minutes after the introduction of

mixing water to the cement and aggregates or the introduction of cement to the aggregate

unless a different time is specified by the Engineer.

24.8.2 Before beginning a run of concrete all hardened concrete and foreign materials shall be

removed from the inner surfaces of mixing and conveying equipments. All conveyances,

buggies and barrows shall be thoroughly cleaned at frequent intervals during the placing of

concrete. Concrete shall be rapidly handled from the mixers to the place of final deposit and

shall not be delivered by spout or trough nor dumped into carriers with a free fall from the

mixer of more than one meter. Every possible precaution shall be taken to prevent

separation of loss of the ingredients while transporting the Concrete.

24.8.3 Each time the work stops, the mixer shall be thoroughly cleaned and when the next mixing

commences, the first batch shall have 10% additional cement at no extra cost to the owner

to allow for loss in the drum.

24.8.4 The workability of the concrete shall be checked at frequent intervals by slump test, where

facilities exist and if required by the Engineer-in-Charge, alternatively the compacting factor

test in accordance with IS: 1199 be carried out.

24.9 Transporting, Placing, compacting & curing:

24.9.1 Procedure for transporting, placing, compacting and curing shall conform to IS 456 (latest

edition). The placing of concrete shall be a continuous operation with no interruption in

excess of 30 minutes between the placing of continuous portions of concrete. Concrete shall

be deposited in a manner to prevent displacing facilities, forms or reinforcement above the

level of the fresh concrete and the formation of seams or planes of weakness within the


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sections. Each layer shall be plastic where a new layer is placed upon it. Concrete shall be

deposited close to its final position as practicable in order to prevent segregation. After

initial set of concrete the forms shall be jarred and no strain or vibrating equipment shall be

placed on the ends of projecting reinforcement.

24.9.2 Concrete shall not ordinarily be placed under water. In unavoidable cases, such concreting

shall be done only with, the specific approval of procedure and application by the Engineer.

Additional cement shall be to the extent of 10% and relevant clauses of IS: 456 (latest

edition) adhered to.

24.9.3 To secure maximum density and eliminate formation of all pockets, the concrete shall be

thoroughly vibrated and worked around all reinforcement, embedded facilities and into

corners of forms during and immediately after placing. Unless other methods are authorized

by the Engineer, mechanical vibrators shall be used for this purpose, the type and operation

of which is subjected to the approval of Engineer-in-charge. The extent of vibration shall be

through the entire depth of each new layer and several centimeters into layer below, with

vibration applied at the point of deposit and uniformly throughout the freshly placed

concrete, no farther apart than radius over which the vibration is visibly effective. Duration

of vibration shall be sufficient to accomplish through compaction and complete embedment

of reinforcement. Due to vibration the tendency for large aggregate to gravitate to lower

elevations shall not relieve the contractor from his responsibility of obtaining a uniform

density throughout the mass. Excess cement paste thus formed at the top of each layer shall

be removed before the succeeding layer is deposited. Hand tamping shall not be permitted.

Contractor shall provide proper equipment or methods for compaction of concrete at

corners or other similar area where conventional methods would not be adequate.

24.9.4 Retiming of concrete or mortar, which has partially hardened, shall not be permitted.

24.9.5 Before pouring the concrete in any work, the written approval of Engineer -in-charge shall be

obtained by the contractor.

24.10 Construction joints:

24.10.1 The locations and details of construction joints not indicated on the drawing must be

approved by the Engineer-in-Charge before concrete is poured. . The construction joints

should be complying with IS 11817.

24.10.2 At the construction joint, a key and extra reinforcement will have to be provided. In

addition to this 12mm dia threaded nozzles of suitable length at spacing not more than


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1.50m c/c will have to be provided along with construction joint. The top of the nozzle will

be kept closed by providing plugs. After pouring of concrete, the plug of the nozzles will be

removed & non-shrink water proof grouting compound mixed with neat cement slurry shall

be injected through the nozzles under pressure by pump to seal all pores cracks and

shrinkages. The nozzles shall be sealed after the injection operation. The pressure grouting

shall be got executed by specialists in this field.

24.10.3 The vertical construction joint in a RCC wall should be formed at pre-determinedposition

with a temporary particle board form work having suitable openings for the continuity of

reinforcement. This particleboard shall be removed after the concrete has set-in sufficiently

to retain its verticality and shape, before concreting is resumed in the adjacent portion.

24.10.4At least two hours must lapse after depositing concrete in the columns or wallbefore

depositing in beams, girders or slabs supported thereon. Beams, girders, brackets and

haunches shall be considered as part of the floor system and shall be placed monolithic

therewith.

24.10.5 Construction joint between pile caps/equipment foundations etc. and floor shall be

provided with PVC water stops. Concurrence and approval of the Engineer will have to be

obtained before providing such joints.

24.10.6 When the work has to be resumed on a surface, which has hardened such surface shall be

roughened. It shall then be swept clean, thoroughly wetted and covered with a 15mm layer

of mortar composed of cement and sand in the same ratio as the cement and sand in the

concrete mix. This 15mm layer of mortar shall be freshly mixed & placed immediately

before the placing of the concrete.

24.10.7 Where the concrete has not fully hardened, all laitance shall be removed by dislodging of

particles of aggregate. The surface shall be thoroughly wetted and all free water removed.

The surface shall then be coated with neat cement grout. The first layer of concrete to be

placed on this surface shall not exceed 150mm in thickness and shall be well rammed against

old work particular attention being paid to corners and close spots.


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24.11 Inserts:

All anchors, anchor bolts, inserts, pipe, conduit, sleeves, floor angles, frames, nosing bolts

etc. and any other items that are required to be cast into the concrete shall be placed in

correct position before pouring. Extra care shall be taken during pouring operation to

maintain their locations. Block-outs and openings shall be kept wherever required.

24.12 Cleaning and finishing:

Except where a special finish is called for, all exposed concrete shall be finished as follows:

24.12.1All fins and other projections shall be neatly chipped, rubbed down and made smooth, form

oil shall be entirely removed by stiff fiber brushes. The use of acid shall not be permitted.

All exposed corners shall be slightly rounded or chamfered. Air holes, cavities and similar

imperfections shall be first saturated with water and filled with a mortar mixture of the same

composition as that used in the concrete. After initial set of mortar, the surface shall be

rubbed down with burlap. A stucco coat shall be allowed to be applied to the surfaces. The

inside surfaces shall be ground smooth with carborundum stone.

24.12.2Except where a separate finish is to be applied, or where a trowel finish is called for

horizontal concrete surfaces shall be floated.

24.12.3 Where a trowel finish is called for the surface shall be floated and steel troweled after

achieving initial set to prevent excess fine materials from working to the surface. The finish

shall be brought to a smooth dense surface free from defects and blemishes. No dry cement

or mixture of dry cement and sand shall be done after the concrete is so hard that no mortar

accumulates on the trowel and a ringing sound is produced as the trowel is drawn over the

surface.

24.13 Curing:

24.13.1Unless otherwise specified all concrete shall be cured by keeping all exposed surfaces, edges

and corners continuously moist for at least seven days after being placed, by spraying,

ponding or covering with waterproof paper or moisture retaining fabric.

24.13.2Immediately after stripping of the forms, water shall be applied directly to the concrete

surfaces. The wetting down operations shall be continuous within the curing time specified.


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24.13.3 As an alternative to continual wetting down of walls, the use of a sprayed-on membrane

may be substituted subject to approval by the Engineer-in-Charge.

24.14 Form work:

24.14.1 All details of formwork, placing, tying etc., shall be subject to the approval of the Engineer

and the Contractor shall submit drawings, when requested, showing details of form

construction. The Contractor shall be responsible for the adequacy of the formwork to

withstand the pressure of freshly placed concrete, or other loads imposed without failure,

movement or deflections of the components parts. Forms shall be true to the shape, lines

and dimensions of the concrete work.

24.14.2 For concrete surfaces that are exposed to view and for all other concrete surfaces

that are to be finished smooth, the lining of forms shall be of smooth non-absorbent lining

material. The type and conditions of such lining for forms shall be subject to the approval of

the Engineer-in-Charge. All edges of panels shall be square and straight in both directions

and all panels shall match perfectly in length, width and alignment as required.

24.14.3 All forms shall be sufficiently tight to prevent the loss of liquid from the concrete. All

rubbish particularly chipping, shaving and saw dust shall be removed from the interior of the

forms before the concrete is placed and the form work in contact with concrete shall be

cleaned and thoroughly wetted or treated with an approved composition to prevent

absorption of water from the concrete. Such composition shall be kept out of concrete with

reinforcement and shall be non-staining and not injurious to concrete.

24.14.4 Form lumber may be reused, provided that it is true, unwrapped, thoroughly clean

and without broken or damaged edges and equal in use in every respect to a new lumber.

All reform lumber shall have the contact surfaces recoiled or re-coated with an approved

composition prior to usage.

24.14.5 Contractor shall keep an accurate record of the date on which the concrete is cast for

each part of the work and the date upon which the formwork is removed.

24.14.6 Removal of forms shall be in accordance with the following requirements:

i) No supporting forms should be removed suddenly in such a manner as to create

shock loading.


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ii) In normal circumstances and where ordinary Portland cement is used, forms may

generally be removed after the expiry of the followings:

a) Walls, columns and vertical faces

of all structural members 24 to 48 hrs as may be decided by

Engineer

b) Slabs (props left under) 3 days

c) Beam soffits (props left under) 7 days

d) Removal of props under slabs:

Spanning up to 4.5m 7 days

Spanning over 4.5m 14 days

20.4.1 Removal of props under beams

and arches

Spanning up to 6m 14 days

Spanning over 6m 21 days

iii) For cement other than ordinary portland cement, the stripping time required as per

25.14.5 shall be suitably modified as per Engineer-in-Charge instruction.

24.14.7 Dimensional Tolerances:

The tolerance on the shapes, lines and diversion are given below:

( a) Sectional dimensions of column &Beam + 5mm

(b) Plumb 3mm for every meter Max. 10 meter for

the concrete structure

(c) Levels & height + 5mm before any deflection has taken

(d)Unevenness of any surface + 3mm


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(e) Length & breath +12mm

(f) Diagonals +1 5mm

24.15 Testing and acceptance criteria:

24.15.1 General:

The testing shall be carried out either at site laboratory to be set up by the contractor or at

any other NABL approved laboratory in accordance with the relevant Indian Standards. The

mould and material for cubes and cylinder shall be supplied by the Contractor, who shall also

arrange to transport the cubes/cylinders to the laboratory at his cost. Samples should be

taken in presence of the representative from the Purchaser and the Contractor. The cost of

testing shall be borne by the contractor.

24.15.2 Cement:

Cement shall be Ordinary Portland Cement of 33grade and 43grade conforming to IS: 269

and IS: 8112 respectively or Pozzolona Portland Cement and shall be obtained from

recognized supplier. The cement to be used shall be of the repute brand such as (i) Gujrat

Ambuja; (ii) L & T; (iii) J. K. Cement; (iv) Shree Cement; (v) Aditya Birla. Cement,(vi) ACC.

The test results in triplicate within three days (3) after completion of test.

24.15.3 Aggregates:

The aggregates shall be tested as and when required by the Engineer in accordance with IS:

2386 Part-I to VIII. The acceptance criteria of the samples tested shall be in accordance with

the requirements of relevant Indian Standards.

24.15.4 Water:

Sampling and testing of water being used for concrete work as per IS: 3550 will be carried

out at regular intervals and wherever directed by the Engineer. The final acceptance criteria

shall be as per IS: 3025.


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24.15.5 Admixtures:

Tests for establishing the various properties of any admixtures, which may be required to be

added, shall be carried out by the contractor free of charge to the owner.

24.15.6 Concrete:

24.15.6.1 The sampling of concrete, making the test specimen and testing procedure etc. shall

be in accordance with IS: 1199 and IS: 516. The size of the specimen shall be 15cm cube.

Normally only compression tests shall be performed but under special circumstances the

Engineer may require other tests to be performed in accordance with IS: 516.

24.15.6.2 Procedure laid down other wise in IS: 456 shall be followed for sampling and strength

test of concrete.

24.15.6.3 The acceptance criteria for the compressive strength shall be as per IS: 456 in

subsequent.

24.15.6.4 Concrete of each grade shall be assessed separately.

24.15.6.5 Concrete shall be assessed daily for compliance.

24.15.6.6 Concrete is liable to be rejected if it is porous or honey combed it’s placing has been

interrupted without providing a proper construction joint; the reinforcement has been

displaced beyond the tolerances specified or construction tolerances have not been met.

However, the hardened concrete may be accepted after carrying out suitable remedial

measures to the satisfaction of the Engineer-in-Charge.

24.15.6.7 However, in exceptional circumstances, the Engineer-in-Charge may, at his

discretion, accept a concrete of lower strength than specified and which is otherwise

acceptable according to IS: 456.

24.15.6.8 Concrete work found unsuitable for acceptance shall have to be dismantled and

replacement is to be done, as per specification by the Contractor. No payment for the

dismantled concrete, the relevant formwork and reinforcement, embedded fixtures etc.

wasted in the dismantled portion shall be made. In the course of dismantling, if any damage

is done to the embedded items or adjacent structures, the same shall be made good, free of

charge by the Contractor to the satisfaction of the Engineer-in-Charge.

24.15.6.9 The entire cost of load testing shall be borne by the Contractor. If a portion of the

Structure is found to be unacceptable, it shall be dismantled and replaced by a new structure

as per specification. The entire cost of dismantling and replacement and restoration of the

site shall be borne by the Contractor.


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24.15.6.10 Payment for concrete which is normally unacceptable as per the criteria laid down in

above Para, but which has been accepted by the Engineer-in-Charge shall be made at a

reduced rate prorate to the strength obtained.

24.15.6.11 If, in the course of dismantling, any damage is done to the embedded items and/or

other adjacent structures, the same, shall be made good free of charge by the contractor to

the satisfaction of the Engineer-in-Charge.

24.16 Measurements and Payment:

24.16.1 The length, breadth and height of concrete shall be measured in metre correct to third

place of decimal. The quantity shall be calculated in cum. correct up to third place of

decimal. Deductions shall be made for all block outs and openings but not for embedments

and reinforcement.

24.16.2 Measurement of formwork shall be based on the contact area of concrete work from

dimensions shown on the drawings. The unit of measurement shall be sqm. Correct up to

second place of decimals.

25.0 Reinforcement:

25.1 (a)Reinforcing steel shall be clean and free from loose mill scales, dust, loose rust and coats

of paints, oil, grease or other coating, which may impair or reduce bond. It shall conform to the

following IS specifications:

(i) Mild steel & medium tensile steel bars and hard drawn steel wire conforming to

Grade-I IS: 432

ii) High strength deformed steel bars conforming to IS: 1786

iii) Structural steel conforming to Gr. A of IS: 2062

iv) Thermo- mechanically treated bars (TMT Bars):

Reinforcement and structural steel of the main producers e.g. SAIL, TISCO and

Rastriya Ispat Nigam Ltd. Shall only be used.

(b) All steel reinforcements, including and above 6mm diameter shall necessarily be of

tested quality. The untested steel reinforcement shall not be allowed to be used.


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(c) Reinforcement accessories shall be furnished by the contractor. Binding wire shall be

annealed iron wire quality not less than No. 16 SWG (1.65mm dia).

(d) Bar supports, chairs and bolsters (as approved by Engineer) shall be sufficiently strong to

support the steel properly.

25.2 Reinforcement steel required for all the works shall be in the scope of contractor.

25.3 The contractor shall furnish reinforcement accessories. Binding wire shall be annealed iron

wire quality not less than No. 16 SWG. (1.65mm dia). Bar support, chairs and bolsters as

required and as approved by the Engineer-in-Charge shall be sufficiently strong to support

the steel reinforcement properly. The cost of all reinforcement accessories shall be included

in the price bid.

25.4 Contractor shall fabricate and place reinforcement to shapes and dimensions, as per IS: 2502

"Code of Practice for Bending and Fixing Bars for concrete Reinforcement” and as indicated

in approved drawings of the contractor. The reinforcement shall be either plain or deformed

mild steel bars conforming to relevant I.S. specifications.

25.5 The contractor shall prepare bar bending schedule on the basis of the approved drawings

marked released for construction and submit the same for approval to the Engineer-in-

Charge. No work shall be commenced without the approval of the Schedule.

25.6 The contractor shall adhere strictly to requirements for concrete cover over steel

reinforcement, protection of bars for bonding with future extensions, columns, ties, splices,

laps, spacer bars, temperature reinforcement, mesh reinforcement and other items in

connection with proper placing.

25.7 Reinforcement shall be placed accurately, tied or welded securely at intersections and

splices and held in position with spacers or other approved supports during concrete

placement. The wire ends should point away from surface.

25.8 Bending and Placing of Reinforcement:

25.8.1 Contractor shall fabricate and place reinforcement to shapes and dimensions, as indicated or

required to carry out intent of drawings and specifications. The reinforcement shall be

either plain or deformed mild steel bars conforming to relevant IS Specifications. The

reinforcements shall be bent and fixed in accordance with procedure specified in IS: 2502.


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25.8.2 The Contractor shall prepare bar-bending schedule on the basis of the drawings marked,

released for construction and submit the same for approval of Engineer-in-Charge. No work

shall be commenced without the approval of the bar-bending schedule.

25.8.3 Any adjustments in reinforcement to suit field conditions and construction joints other than

shown on drawings shall be subject to approval of Engineer-in-Charge.

25.8.4 The Contractor shall adhere strictly to requirements for concrete cover over steel

reinforcement, protection of bars for bending with future extensions, columns, ties, splices,

laps, spacer bars, temperature reinforcement, mesh reinforcement and other items in

connection with proper placing.

25.8.5 Reinforcement shall be placed accurately tied or welded securely at intersections and splices

and held in position with spacers or other approved supports during concrete placement.

Tie wire ends shall be pointed away from surface.

25.8.6 The Contractor shall furnish the reinforcement accessories. The wire shall be annealed iron

wire quality. Bar supports, chairs, spreaders, spacers and bolsters shall be sufficiently heavy

to support the reinforcement steel properly and shall be approved by the Engineer-in-

Charge. No separate payment shall be made on account of the binding wire.

25.9 Measurement and Payment:

Measurement of reinforcement steel shall be based on the calculated weight of steel

actually used in tones correct up to third place of decimal. No allowance shall be made for

wastage. No separate payment shall be made for binding wire. The chairs, lap lengths and

spacers as approved by the Engineer-in-Charge shall be measured as per the measurement

of reinforcement and shall be payable. The weight of reinforcement shall be calculated on

the basis of standard weights given in IS: 1786.

Any adjustments in reinforcement to suit field conditions and construction joints other than

shown on approved drawings shall be subject to approval of the Engineer-in-Charge.

26.0 Miscellaneous Steel Supply and Erection:

26.1 Scope:

The specification covers the technical requirement for the supply, fabrication, erection and

installation of all miscellaneous steel by the contractor if required by HPGCL. Supply of


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miscellaneous steel shall be in the scope of contractor. The extent and type of miscellaneous

steel to be fabricated, erected etc. shall be as per the detailed construction drawings.

Miscellaneous steel shall include items such as rolled sections like angles, joists, channels,

plates, etc. bolts set in concrete as for in pedestals, anchor blocks etc.

The above list is provided only as an illustration of the type of steel items to be considered as

miscellaneous steel and some items listed may not appear in the actual list. It shall also not

be construed as limiting to such items only.

26.2 Materials:

The steel shall conform to IS: 226 & IS: 2062 and bolts, nuts, electrodes etc. shall conform to

relevant Indian Standards. Supply of required structural steel if any shall be in the scope of

contractor.

26.3 Fabrication:

27.3.1 The fabrication drawing along with bill of the materials for structural steel if required

shall be prepared by the contractor in accordance with the requirements as indicated in

detailed construction drawings and will be submitted to the purchaser/consultant for

approval. After approval of the fabrication drawing Contractor shall furnish electrodes at his

own cost and welding shall conform to IS: 816. The fabrication work shall generally conform

to IS: 800.

Miscellaneous Steel Supply and Erection

The Work for dismantling,fabrication and re-erection of Foot Bridge at elevation 231.25 Mtr

including bolts, nuts, electrodes etc. shall conform to relevant Indian Standards shall be in

the scope of contractor any additional steel member if required for the strengthening of the

Foot Bridge shall be in the contractor scope.

The electrode for welding purpose shall confirm to IS 814 and shall be either of the following

make:

(i) AdvaniOerlikon;

(ii) Indian Oxygen Ltd;


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(iii) Phillips Industries Ltd. and their subsidiaries “PIECO”;

(iv) D & H Secheron Electrodes (P) Ltd.

26.4 Erection:

The contractor shall erect all miscellaneous steel in accordance with the drawings and these

specifications including setting materials in concrete or grouting pieces in place, furnishing

all labour, materials, scaffolding, tools and services necessary for and incidental to its

transporting, unloading, storing, handling and erection. Contractor shall furnish welding

rods and arrange for field welding as required in accordance with IS: 816.

26.5 Installation & Safety Requirements:

26.5.1 During erection, contractor shall provide necessary temporary bracing or supports to

ensure proper installation of the materials. All material shall be erected in the true

locations as shown on the drawings with accurate plum and level. All installations shall be

carried out within the tolerances specified in the drawings.

26.5.2 All operations connected with welding and cutting, equipment’s shall confirm to the safety

requirements given in IS: 818.

26.5.3 Inspection and testing of the welds shall be as per IS: 822.

26.6 Painting:

All structural steel member surface shall be provided a shop coat of red oxide zinc chromate

primer touch up, a second coat of primer after erection and thereafter with three coats of

synthetic enamel paints of approved quality and shade confirming to relevant IS code.

26.7 Measurement and Payments:

26.7.1 The contractor along with fabrication drawings shall submit bill of quantities for approval.

The structural weight for various components shall be calculated on the basis of standard

steel table published by BIS in Kg correct up to second place of decimal. No payment for the

weight of bolts, nuts, washers, erection bolts and making fabrication drawings shall be


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payable. The weight for payment purpose shall be considered as per the approved bill of

material.

26.7.2 The rate to be quoted shall be inclusive of preparation of fabrication drawings, bill of

materials, supply of all materials, fabrication, erection, installation, painting, consumables,

labour, T & P etc. specified above. The payment of structural steel shall be as under:

i. 15% of quoted rates on dismantling and removal of Foot Bridge.

ii. 25% of quoted rates after fabrication as per site requirement

iii. 15% of quoted rates on raising of pedestals of Foot Bridge upto required elevation

iv. 35% of quoted rates on re-erection of Foot Bridge at elevation 231.25 Mtr.

v. 10% of quoted rates on painting and completion of Foot Bridge in all respect

26.8 Plastering:

28.1 Scope of Work

The scope of work includes the plastering of specified thickness on RR Stone masonry/ Brick

masonry works at ash pond area with cement sand mortar in single / double coats as

specified in drawing including all labour, material, T & P, required for successful completion

of the work.

28.2 Material

(a) Ordinary Portland cement shall be of 33 Grade or Grade 43 Grade conforming to IS:

269 (Latest) and IS: 8112 (Latest) respectively.

(b) The sand of plastering shall conform to IS: 1542-1977.

(c) Water proofing compound of approved make @ 2% of quantity of cement / as

recommended by the manufacturer shall be used.

(d) The ingredients for mortar shall be mixed in specified proportion by volume (1 Cement: 4

Fine sand).


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28.3 Preparation of Surface

The obtain satisfactory bond between the masonry and the plaster, the joints of RR Stone

masonry/ brick masonry shall be raked out with a hook to a depth of about 20 mm if not

done earlier. The wall shall be damped evenly before applying the plaster.

28.4 Laying

After the surface has been prepared dabs or reference marks of mortar shall be fixed to

ensure that the plastered surface shall be truly plain and that the plaster coat shall have the

required thickness. Cement plaster 20 mm average thick shall be applied in two coats. The

thickness of under coat shall be 13mm (app.) and that of finishing coat shall be 7mm (app.).

Cement plaster 15 mm thick shall be applied in single layer. The mortar of specified mix shall

be applied uniformly between the mortar dabs and finished off with a wooden straight edge

reaching across the dabs and shall be finished of with dasterar wooden float.

After preparing the surface and laying the dabs as detailed above, the under coat shall be

applied uniformly thick by laying on or throwing from the trowel. The mortar shall be well

pressed so that the raked joints are properly filled. The surface shall be left rough and

furrowed 2 mm deep with a scratching tool diagonally both ways to form a key for the

finishing coat so as to have a proper bondage. The surface shall be kept wet till the finishing

coat is applied. The finishing coat shall be started within 48 hrs. of the first coat applied.

For the finishing coat the mortar shall be applied uniformly between the mortar dabs and

finished off with a wooden straight edge reaching across the dabs and shall be finished off

with wooden float.

28.5 Curing

Curing shall be started as soon as the plaster has hardened sufficiently not to be damaged

when watered.

28.6 Defects

Any cracks in the plaster, or parts which sound hollow when tapped or are found to be soft

or otherwise defective after the plaster has dried, shall be cut out in rectangle or square and

re-plastered by the contractor as directed by Engineer-in-Charge.


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28.7 Measurement & Payment

Length and breadth shall be measured in meter correct to the second place of decimal and

its area shall be calculated in square meters correct to second place of decimal. The

operations for plaster includes plastering of RR stone masonry surface with the specified

mortar, preparing, cleaning and watering the surface to be plastered, provision for erection

and removal of scaffolding / staging for all leads and lifts and provision of all T & P labour,

material and all such incidental items required for the completion of the work.

29.0 R.C.C. Pipes of Class ‘NP3’:

29.1 Scope:

The work shall comprise of providing all material/T&P/ labour, etc. and doing all operations

necessary to complete for supply and laying R.C.C. non-pressure pipes NP3 type in

accordance with drawings and specifications.

29.2 Material:

Pipes shall conform to IS: 458. They shall be manufactured by centrifugal (or spun) process.

All pipes shall be true to shape, strength, perfectly sound and free from cracks and flows.

The external and internal surface of the pipes shall be smooth and hard. The pipes shall be

free from defects resulting from imperfect grading or the aggregate mixing or molding.

Concrete used for the manufacture of RCC pipes and collars shall not be leaner than M-15.

The maximum size of aggregate should not exceed 1/3rd of the thickness of the pipe or 20

mm whichever is smaller. The reinforcement shall extend throughout the length of the pipe.

The circumferential and longitudinal reinforcements shall be adequate to withstand the

specified hydrostatic pressure and further bending stresses due to the weight of water when

running full across a span equal to the length of pipe plus three times its own weight. These

will conform to provisions laid down in IS: 458.

29.3 Laying of Pipes:

Loading, transporting and unloading of concrete pipes shall be done with care. Handling

shall be such as to avoid impact. Gradual unloading by inclined plane or by chain block is

recommended. All pipe sections and connections shall be inspected carefully before being

laid. Broken or defective pipes of connections shall not be used.


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Pipes shall be lowered into the trenches carefully. Mechanical appliances may be used.

Pipes shall be laid true to line and grade as specified. Laying of pipes shall proceed up-grade

of a slope. The socket end shall face upstream.

In cases where the natural foundation is inadequate, the pipe shall be laid either in concrete

cradle supported on proper foundations or on any other suitably designed structure. If a

concrete cradle bedding is used the depth of concrete below the bottom of the pipe shall be

at least ¼ of the internal dia. of the pipe subject to the minimum of 10cm and a maximum

30cm. The concrete shall extend up the sides of the pipe at least to a distance of ¼ of the

outside diameter of pipes 300 mm and over in dia. The pipe shall be laid in this concrete

bedding before the concrete has set. Pipes laid in trenches in earth shall be bedded evenly

and firmly and as far up the haunches of the pipe as to safely transmit the load expected

from the backfill through the pipe to the bed. This shall be done either by excavating the

bottom of the trench to fit the curve of the pipe to form an even bed. Necessary provision

shall be made for joints wherever required.

When the pipes are laid completely above the ground, the foundations shall be made even

and sufficiently compacted to support the pipeline without any material settlement.

Alternatively, the pipeline shall be supported on rigid foundations at intervals. Suitable

arrangements shall be made to retain the pipeline in the proper alignment, such as by

shaping the top of the supports to fit the lower part of the pipe. The distance between the

supports shall in no case exceed the length of the pipe. The pipe shall be supported as far

as possible close to joints. In no case shall the joint come in the centre of the span. Care

shall be taken to see that superimposed loads greater than the total load equivalent to the

weight of the pipe when running full shall not be permitted.

29.4 Jointing of Pipes:

As described in the working drawings, the specific joint will be provided. Some of the

typical joints are described below:

29.4.1 Collar Joint (Rigid):

The two adjoining pipes shall be butted against each other adjusted in correct position. The

collar shall then be slipped over the joint, covering equally both the pipes. The annular

space shall be filled with stiff mixture of cement mortar 1:2 (1 cement: 2 fine sand), which


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shall be rammed with caulking tool. After a day’s work any extraneous materials shall be

removed from the inside of the pipe and the newly made joint shall be cured.

29.4.2 Flush Joint (Internal):

This joint is generally used for culvert pipe of 60 cm dia. and over. The ends of the pipe are

specially shaped to form a self-centering joint with an internal jointing space 1.3 cm wide the

finished joint is flush with both inside and outside with the pipe wall. The jointing space is

filled with cement mortar 1:2 (1 cement: 2 fine sand) mixed sufficiently dry to remain in

position when forced with a trowel or hammer.

After a day’s work any extraneous material shall be removed from the inside of the pipe and

the newly made joint shall be cured.

29.4.3 Flush Joint (External):

This joint is suitable for pipes which are too small for jointing from inside. This joint is

composed of specially shaped pipe ends. Each end shall be butted against each other and

adjusted in correct position. The jointing space shall then be filled with cement mortar 1:2

(1 cement : 2 fine sand) sufficiently dry and finished off flush. Great care shall be taken to

ensure that the projecting ends are not damaged as no repairs can be readily affected from

inside the pipe.

29.5 Opening to Traffic:

No traffic shall be permitted to cross the pipeline unless concrete around the pipe is

completed and cured for ten days.

29.6 Measurement and Payment:

The measurement of different type of pipe shall be made in running meter correct up to

second place of decimal. The rate shall be inclusive of supplying, laying and jointing etc.

However, the concrete bedding, if required, shall be paid as per the item of concreting. The

other items shall be measured as per the item specified in the schedule. The quoted price

shall also include supply of materials including special pieces, relevant erection with relevant

sealing, hangers of any kind, length and size as required for fastening the single piece as well

as any masonry work for embedding the hangers and testing of joints by relevant methods.


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30.0 Metallic Roads:

30.1 Preparation of Sub-grade

30.1.1 Earthen Sub-grade

The surface of the formation for a width equal to that of sub-base course shall be first cut to

a depth below the proposed finished level, equal to the combined depth of Sub-base and

wearing course, due allowance being made for compaction, It shall then be cleaned of all

foreign substances. Any ruts of soft yielding places that appear due to improper drainage

conditions, traffic hauling and other cause shall be corrected and the sub-grade dressed off

parallel to the finished profile. The sub-grade shall then be sprinkled with water and rolled

with minimum of 5 numbers of passes of 8-10 tonne smooth wheeled roller till the soil is

evenly and densely compacted. All undulations in the surface that might develop due to

rolling shall be made good with earth or quarry spoils as the case may be, and sub-grade

rolled.

30.2 Sub-base

30.2.1 Material

Suitable cool pick stone (reject coal boulders) available in Khedar, Hisar Thermal Plant area

shall be used in 200m m thick sub base course of road. The cool pick stone shallbe issued

free of cost to the contractor on as is where is bases and contractor shall arrange for

breaking them further in the require sizes. Loading, Unloading, handling and transportation

of the same from Power Plant to work site shall be at contractors own cost and deemed to

be covered in his quoted unit rate for sub base course of road specified in the price

schedule.

30.2.2 Immediately prior to laying of sub-base, the sub-grade already finished shall be prepared by

removing all vegetation and other extraneous matters, lightly sprinkled with water, if

necessary and rolled with one pass of 8-10 tonne smooth wheeled roller.

30.2.3 Sub-base shall be of 200mm compacted thickness to be laid in two layer layers of 100mm

thick each.


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30.2.4 The coarse aggregate shall be spread uniformly upon the prepared base in such quantities

that the thickness of compacted layer is 100mm. The spreading shall be done from stack

piles along the sides of the roadway and not directly from vehicles. In no time shall the

aggregate be dumped in heaps directly on the surface prepared to receive the aggregate

nor shall hauling over uncompacted or partially compacted base is permitted. Surface of the

aggregate spread shall be carefully checked with templates and all high or low spots

remedied by removing or adding aggregate as may be required. No segregation of large or

fine particles shall be allowed and the coarse aggregate, as spread shall be of uniform

gradation with no pockets of fine material. The coarse shall be spread more than 3 days in

advance of the subsequent construction operation.

30.2.5 Immediately following the spreading of the coarse aggregates, rolling shall be started with

three-wheeled power rollers of 8 to 10 tonne capacity or tandom or vibratory rollers of

approved type. Expect on super-elevated portions where rolling shall proceed from inner

edge to the outer, rolling shall begin from edges gradually progressing towards the centre.

First the edge/edges shall be compacted with roller running forward and backward. The

roller shall then move inwards parallel to the centre line of the road, in successive passes

uniformly overlapping preceding tracks by at least one half width. Rolling shall be

discontinued when aggregates are partially compacted with sufficient void space in them to

permit application of screenings. During rolling light sprinkling of water may be done if

necessary. Rolling shall not be done when sub-grade is soft or yielding or when sub-grade is

soft or yielding or when it causes a wave likes motion in sub-grade or sub-base course.

30.2.6 After coarse aggregate has been rolled, screenings of above material (Coal pick stones) to

completely fill the voids shall be applied gradually on the surface. These shall not be damp or

wet at the time of application. Dry rolling shall be done while screenings are being spread so

that vibrations of the roller cause to settle into the voids of the coarse aggregate. The

screening shall be applied at a slow and uniform rate (in three or more applications) so as to

ensure filling of all voids. This shall be accompanied by dry rolling and brooming with

mechanical broom, hand brooms or gunny bags. These operations shall continue until no

more screenings can be forced into voids of the coarse aggregate. The applications of

screenings shall be carried out in only lengths of roads, which could be completed within one

day’s operation. After screenings have been applied, the surface shall be copiously sprinkled

with water, swept and rolled. Hand brooms shall be used to sweep wet screenings into voids


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and to distribute them evenly. The sprinkling, sweeping and rolling operations shall be

continued with additional screenings applied, if necessary, until the coarse aggregate had

been thoroughly keyed, well bonded and firmly set in its full depth and a grout has been

formed of the screening

30.3 Base Course (Water bound macadam)

30.3.1 Material

Coarse aggregate shall be crushed and broken stone. The aggregates shall conform to the

physical requirement as set forth below:

Type of

Construction

Test

Test Method

Requirements

base Course Los Angeles

Abrasion Value

or

Aggregate Impact

Value

Flakiness Index

IS: 2386 (Part IV)

IS: 2386 (Part IV)

or IS: 5640

IS: 2386 (Part I)

50% max.

40% max.

15% max.

Crushed stone shall be hard, durable, of approved quality and free from excess of flat,

elongated, soft and disintegrated particles, dirt and other objectionable matters.


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30.3.2 Base shall be of 200 mm compacted thicknesses to be laid in two layers of 100mm thick

each. The base course shall be graded coarse aggregates of crushed and broken stone and

screenings. The coarse aggregate shall conform to grading requirement as set forth below:

Size range

Sieve designation Percent by weight passing

the sieve.

63mm to 45 mm

53mm to 22.4 mm

90mm

63mm

53mm

45mm

22.4mm

63mm

53mm

45mm

22.4mm

11.2 mm

100

90 - 100

25 - 75

0 - 15

0 -5

100

95 - 100

65 - 90

0 - 10

0 -5

30.3.3 Screenings to fill the voids in the coarse aggregate shall generally consist of the same

material as the coarse aggregate. Screenings shall conform to grading requirement as set-

forth below:

Size of screening Sieve designation Percent by weight passing

the sieve

12.5 mm 12.5 mm

10.0 mm

4.75 mm

100

90 – 100

10 – 30


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150 mm

26.8 – 8

30.3.4 Immediately prior to laying of sub-base, the sub-grade already finished shall be prepared by

removing all vegetation and other extraneous matters, lightly sprinkled with water, if

necessary and rolled with one pass of 8-10 tonne smooth wheeled roller.

30.3.5 The coarse aggregate shall be spread uniformly upon the prepared base in such quantities

that the thickness of compacted layer is 100mm. The spreading shall be done from stack

piles along the sides of the roadway and not directly from vehicles. In no time shall the

aggregate be dumped in heaps directly on the surface prepared to receive the aggregate nor

shall hauling over uncompacted or partially compacted base is permitted. Surface of the

aggregate spread shall be carefully checked with templates and all high or low spots

remedied by removing or adding aggregate as may be required. No segregation of large or

fine particles shall be allowed and the coarse aggregate, as spread shall be of uniform

gradation with no pockets of fine material. The coarse shall be spread more than 3 days in

advance of the subsequent construction operation.

30.3.6 Immediately following the spreading of the coarse aggregates, rolling shall be started with

three-wheeled power rollers of 8 to 10 tonne capacity or tandom or vibratory rollers of

approved type. Expect on super-elevated portions where rolling shall proceed from inner

edge to the outer, rolling shall begin from edges gradually progressing towards the centre.

First the edge/edges shall be compacted with roller running forward and backward. The

roller shall then move inwards parallel to the centre line of the road, in successive passes

uniformly overlapping preceding tracks by at least one half width. Rolling shall be

discontinued when aggregates are partially compacted with sufficient void space in them to

permit application of screenings. During rolling light sprinkling of water may be done if

necessary. Rolling shall not be done when sub-grade is soft or yielding or when sub-grade is

soft or yielding or when it causes a wave likes motion in sub-grade or sub-base course.

30.3.7 The rolled surface shall be checked transversely and longitudinally with templates and any

irregularities corrected by loosening the surface, adding or removing necessary amounts of

aggregate and re-rolling until the entire surface conforms to the desired camber and grade.

In no case, shall the use of screenings be permitted to make up depressions.


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30.3.8 After coarse aggregate has been rolled, screenings to completely fill the voids shall be

applied gradually on the surface. These shall not be damp or wet at the time of application.

Dry rolling shall be done while screenings are being spread so that vibrations of the roller

cause to settle into the voids of the coarse aggregate. The screening shall be applied at a

slow and uniform rate (in three or more applications) so as to ensure filling of all voids. This

shall be accompanied by dry rolling and brooming with mechanical broom, hand brooms or

gunny bags. These operations shall continue until no more screenings can be forced into

voids of the coarse aggregate. The applications of screenings shall be carried out in only

lengths of roads, which could be completed within one day’s operation. After screenings

have been applied, the surface shall be copiously sprinkled with water, swept and rolled.

Hand brooms shall be used to sweep wet screenings into voids and to distribute them

evenly. The sprinkling, sweeping and rolling operations shall be continued with additional

screenings applied, if necessary, until the coarse aggregate had been thoroughly keyed, well

bonded and firmly set in its full depth and a grout has been formed of the screenings.

30.3.9 Second layer of 100mm thick sub base shall be laid as per procedure and manner specified

above.

30.3.10 The binding material used shall consist of suitable material approved by Engineer having a

plasticity index value less than 6 as determined in accordance with IS: 2770 (Part – V).

Application of binding material will not be necessary, when the screenings used are of

crushable type such as morrum or gravel.

30.3.11 Water bound macadam base course shall be of a consolidated thickness of 100mm laid in

one layer.

30.3.12 Construction operation for above bound macadam base course shall be similar to that

detailed herein above for sub-base course.

30.3.13 Binder material as defined in Clause 4.3.2 shall be applied successively in two or more thin

layers at a slow and uniform rate. After each application, the surface shall be copiously

sprinkled with water, the resulting slurry swept in with hand broom or mechanical brooms

to fill the voids properly and rolled during which, water shall be applied to the wheels of the


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rollers. if necessary, to wash down the binding material sticking to them. These operations

shall continue until the resulting slurry of the filling of voids from a wave ahead of the

wheels of the moving roller.

30.3.14 After the final compaction of WBM course, the same shall be allowed to dry over night. Next

morning, hungry spots shall be filled with screenings and binding materials as directed and

lightly sprinkled with water and if necessary, rolled. No traffic shall be allowed on the road

until the macadam surface has set for at least 4 days. Road shall be kept watered so that it

remains in a damp condition under traffic for at least 14 days.

30.3.15 Rectification: Where the surface irregularity fall outside the specified tolerances the

contractor shall be liable to rectify it to the satisfaction of Engineer – in – Charge by adding

fresh material and recompacting to specifications where the surface is low. Where the

surface is high the full depth of the layer shall be removed and replaced with fresh material

and compacted to specifications.

30.3.16 Measurement

Formation of sub-grade, sub-base and water bound macadam base shall be measured as

finished work in position in cubic meters correct up to three places of decimal.

The longitudinal profile shall be checked during execution with a three meter long

straight edge and graduated wedge at the middle of each traffic lane along the road.

Similarly the transverse profile shall be checked with adjustable templates at intervals of 10

meters

31. Toe Drains:

Brick masonry toe drains shall be provided throughout the length of dyke at the downstream

toe of Ash Dyke as indicated in the drawings and as per the details shown therein.

32. HIGH DENSITY POLYTHYLENE PIPES (HDPE)

32.1 Scope:- The scope of work includes providing and laying of HDPE pipesfor drainage

ofwater wherever required in Ash Dyke including all labour, material T & P,

supervision etc.


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32.2 Material:-HDPE pipes shall conform to IS: 4984:1995 (latest edition) having pressure

rating of pipes PN 6 (Maximum permissible working pressure 0.60 MPa), and PE 80

Material Grade. The upper half portion of the pipe shall be perforated as per drawings

&direction of Engineer-In- charge. The material shall be got approved from the

purchaser/ consultant before laying at site. The necessary test results of the material

shall be supplied by the contractor. Material shall be ISI marked.

32.3 Laying:- HDPE pipes shall be laid on the firm ground as per drawing. Pipes shall be

wrapped with non-woven geotextile before laying in position.

32.4 Measurement:-Pipe laid at site shall be measured correct upto a centimetre and paid

as per contractual rates.


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ANNEXURE - I

Raisings of Ash Dyke of Unit 1&2 from EL.227.25m To 231.25m including Allied Civil Works

at RGTPP, Khedar, Hisar

Ash/Earthwork Inspector's daily Report

Date………………………

Shift……………………………

Weather……………………………..

Name of Contractor's Supervisor……………………………………………

Type of Roller Equipment used……………………………………………..

Weight of Roller……………………………………………………………..

(A) EXCAVATION

1. Type of Excavator

2. Depth of Cut

3. Type of Soil

4. Borrow Pit Location

5. Whether Water added at Borrow Pit

6. Moisture Content (%)

(B) FILL CONDITIONS

1. Location of Fill

2. Elevation

3. Whether Water added at the Fill

4. Moisture Condition before Rolling

5. Roller passes

(C) TEST DATA

1. Field

(a) Location of Sampling Point

(i) R.D.

(ii) Off Set


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(b) Serial No.

(c) Moisture Content (%)

(d) Dry Density (gm./cc)

(e) Plasticity needle reading (Kg/sq.cm)

(f) Quality of Earthwork / Ash fill rolled.

2. Laboratory Check

(a) Serial No.

(b) Optimum Moisture Content (%)

(c) Maximum Dry Density (gm/cc)

(D) COMPACTION EFFICIENCY

1. Filed Moisture Deviation from Optimum

2. Percentage Compaction


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The details of works are shown in the following tender drawings appended herewith.

In case of any discrepancy between the details on the drawings and those mentioned in the

technical specifications the details shown on the drawings shall prevail.

Sr.

No.

DRAWING NUMBER TITLE

1 No. CED/SM/RGTPP/01/R1 Dyke General Arrangement & details.

2 No. CED/SM/RGTPP/02/R0 Dyke General Arrangement & details

Raisings of Ash Dykes from EL.227.25m To 231.25m including ... · including Allied Civil Works at...

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