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• From the President’s Desk 1

• News from Centres 2

• Selected Seminar Papers 7

• ICI Students’ Chapters 20

• Forthcoming Events 25

• New Members 26

Contents

From the President’s Desk

May 2011 Vol. 2 Issue: 05

ICI Update – May 2011 01

One welcome trend which is clearly discern-ible during the recent past is the consistent growth in the addition of stu-

dents’ chapters. ICI has been add-ing at least one student chapter every month during the past more than a year. This issue contains re-ports on new students’ chapters, including the one at IIT Madras. Local ICI centres should take a clue from this trend and devote lit-tle more time and efforts in bring-ing students of civil/structural/environmentalengineering from their region into the ICI fold. ICI members who hold faculty posi-tions should encourage students to open chapters in their respec-tive colleges. I am initiating a proposal to give a further boost to this trend, so that the student fraternity feels that they are real beneficiaries. The proposal will be discussed during the next Govern-ing Council meeting.Incidentally, I feel that we need to take serious cognizance of the recent events in Japan. All of us were shocked and greatly per-turbed to witness the catastro-

phe created by the earthquake and the tsunami that had struck Japan on March 11, 2011. The ef-fects of the sad event are still un-folding. According to the United States Geological Survey (USGS), this earthquake was the largest ever recorded in Japan and is the world’s fifth largest earthquake to strike since 1900. Japan is believed to be well-equipped and prepared to resist earthquakes of high in-tensity; yet the devastations were horrendous. The tragic events in Japan raise many questions amongst Indians, especially amongst the engineer-ing fraternity. Is India prepared to withstand high-intensity earth-quakes and tsunamis? Prime Minister Dr. Manamohan Singh was quick to order a “technical review” of all critical installations. The safety of critical structures in-cluding nuclear installations is cer-tainly important. However, equally pertinent question is about the safety of all structures in densely populated urban or rural areas. In recent years reasonably high-intensity earthquakes have struck India in quick succession: Khilari (Latur) in 1993, Jabalpur in1997, Chamoli in 1999, Bhuj in 2001, An-daman in 2002, Sumatra in 2004,

Kashmir in 2005 and Sikkim in 2006. It is estimated that nearly 70% of the Indian land mass is prone to medium-to-high intensity earthquakes. Despite certain laud-able efforts of many organizations and individuals, the awareness about earthquake-resistant design and construction is still lacking in India. Are we are in a position to state confidently that the coun-try is well prepared to withstand large earthquakes? Certainly, we have a long way to go in achiev-ing tangible results in earthquake-preparedness. Any earthquake is a sad reminder to us about our shortcomings. In fact, we should consider it as a wake-up call.In this issue, we are including a write-up by Prof C V R Murty on the theme “Preparing for Earth-quakes: Where India Stands?” Considering the sensitivity of the topic, we would welcome worth-while contributions on this theme and request readers to respond at an early date. The contributions can also cover the role that ICI can play in creating awareness and ren-der help in building earthquake-resistant structures in India.

Vijay KulkarniPresident

ICI AWARDSNominations are invited for the following ICI Awards for the

year 2010-2011

1. Outstanding Concrete Structures.

2. Outstanding Concrete Technologist.

3. Best Paper published in ICI Journal.

4. Best Paper on Construction Techniques.

5. Life Time Achievement (North, East, West and South).

6. Best Centre.

7. Young Scientist.

8. Outstanding Prestressed Concrete Structure in the Country.

9. Best Student Chapter.

Last date for receipt of nominations is : 7th July 2011.

R.Radhakrishnan

Secretary General


16th ICI (KBC) – Civil aid (Torsteel) Endowment

Lecture” was organized on 28th April 2011. Invited

speaker, Mr. Jose Kurian Chief Engineer, Delhi Tour-

ism & Transport Development Corporation, New

Delhi in his Endowment Lecture spoke on “Con-

struction of Underpasses under Restricted Bound-

ary Conditions”. The lecture brought out several

aspects of construction project in its entirety during

planning, analysis, design and construction Stages.

Four different construction projects,

Punjabi Bagh Grade Separator, Madhuban Chowk

Underpass, Prem Bari Underpass, Moolchand Un-

derpass within New Delhi limits were discussed.

Proximity to flowing canal, railway line, Metro line,

and flyovers compounded by high water table re-

sulting in enormous uplift posing severe constraints

in design, construction and choice of material were

presented. Lecture was highly

educative and informative.

Earlier Mr. Raj Pillai, Chairman, ICI -KBC welcomed

the gathering and briefed about the ICI-Torsteel En-

dowment Lecture. Dr. R. Nagendra, Technical Di-

rector Civil-Aid, co-ordinated the programme. Dr.

M. N. Hegde, Secretary, ICI - KBC proposed vote of

thanks.

Mr. Jose Kurian, C.E. DTTDC, Lighting the Lamp – Inauguration

Dr. C. S. Viswanatha Lighting the Lamp during Inauguration

Mr. Jose Kurian delivering the Endowment Lecture

Section of the Audience

News from Centres

ICI-Kar. Bengaluru Centre


Dr. Manu Santhanam, Associate Professor, IIT Madras, Chennai delivering the Technical Lecture

Er. K. Jayasankar, Chairman, ICI – TNCC, Welcoming the participants

ICI Tamil Nadu Chennai Centre organized a Techni-

cal Lecture on Monday the 19th April 2011 at ICSR

Hall, IIT Madras. Dr. Manu Santhanam, Associate

Professor, IIT Madras spoke on ‘Water Proofing So-

lutions for Concrete Structures’

During his speech, he stressed upon the need to

have good quality of cover zone concrete as a strin-

gent security measure to tighten the entry of water

into the structure. He classified the water proofing

solutions as positive side/negative side, below/above

the ground/roof. He also differentiated between wa-

ter tight (read: damp proof) and water proof. He also

dwelled upon the various techniques of water proof-

ing solutions prevalent in the industry such as water

proofing compounds, damp proofing admixtures,

permeability resisting admixtures, crystalline water

proofers, chemical admixtures, grout materials, sur-

face treatment techniques – such as coatings, seal-

ants, penetrants (impregnates). He also cautioned

the listeners that the applications of the various wa-

ter proofing solutions deserve more merit else the

long term performance of the water proofing system

becomes questionable.

He concluded his speech by saying that though plen-

ty of systems are available for effective water proof-

ing treatments, nothing can substitute the good con-

struction and concreting practices.

This was followed by the sponsor’s presentation.

Mr. Atul V. Vaidya, Head – Business Development,

Construction Chemicals Division of M/s Pidilite

Industries Limited gave an elaborate presenta-

tion on their offerings for the various water proof-

ing treatments. Mr. Sanjiv Dutta, Chief – Industries

& Infrastructures was also present during the

occasion.

There was a greater interaction among the partici-

pants and the speakers. Initially, Mr. K. Jayasankar

Chairman of ICI TNCC welcomed the gathering and

Mr. K. G. K. Moorthy, Secretary & Treasurer of ICI

TNCC gave the vote of thanks

ICI-Tamil Nadu Chennai Centre

News from Centres


Mr.Atul Vaidya, Head Business Development, Construction Chemicals Division, M/s. Pidilite

Industries Limited, Mumbai giving product presentation

Er.BRK Nair, GM (Projects), Gammon India Limited giving memento to Dr .Manu Santhanam, Associate Professor, IIT Madras, Chennai

Section of Audience

ICI Ghaziabad Centre

Two days National Conference on Repair and Re-

habilitation of Concrete Structures was organized

at NTPC Power Management Institute, Sector 16A,

Noida during May 6-7, 2011 by Indian Concrete In-

stitute, Western UP Centre Ghaziabad in association

with Indian Association of Structural Engineers and

Association of Structural Rehabilitation.

Mr. CS Prasad, Director General, Central Public

Works Department, New Delhi was the Chief Guest

of the Inaugural function. A revised reprint of CPWD

handbook on Repair and Rehabilitation of Concrete

Structures was also released by him during the Con-

ference.

This Conference was attended by more than 200 del-

egates/ authors/ manufacturers / exhibitors etc. from

various corners of the country. During the Confer-

ence, around seventy research papers on different

themes of the Conference such as Condition assess-

ment and Distress-diagnostic techniques; Causes of

distress; Repair and rehabilitation techniques; Ma-

terials for repair and rehabilitation; Durability, ser-

viceability and economy; New Techniques and Ma-

terials for Repair/ Rehabilitation and their life cycle

evaluation; Long-term health monitoring of struc-

tures; and Case studies were presented. Padmashree

Dr AS Arya; Prof DK Paul, IIT Roorkee; Prof K Ga-

nesh Babu, IIT Chennai; Dr GM Sabnis, USA; Dr SK

News from Centres


Manjrekar, Mumbai; Dr. DG Kadkade, Noida; Prof

AK Tiwari, Mumbai and other eminent experts pre-

sented their papers and shared their views.

During the two day Conference, causes of dam-

ages and distresses in concrete structures, condi-

tion surveys, repair methods, repair materials, seis-

mic retrofitting of bridges and roads, fire damaged

structures, and health monitoring, along with case

studies were discussed in detail. Stress was given to

proper diagnosis of the structure to find out the root

cause(s) of the distress before carrying out repair

and rehabilitation work. Importance of selection of

proper repair material, repair method and availabil-

ity of skilled manpower was emphasized. It was sug-

gested that ITI should train masons, carpenters, bar-

benders etc. for this specialized field of Repair and

rehabilitation. It was felt that engineers should be

taught this subject in undergraduate degree course.

It was decided to formulate the recommendations of

the Conference to be sent to Govt. and other stake

holders for implementation.

Mr.AK Sharma, Chief Engineer, CDO, CPWD, New

Delhi and Dr.Rajeev Goel, Scientist, CRRI, New

Delhi were the Convener and Organising Secretary

of the Conference respectively. This is the first time

such a National Conference on this specialized topic

of Repair and Rehabilitation of Concrete Structures

was organised in this region.

Dr.Rajeev Goel

Honorary Secretary,

ICI-Ghaziabad Centre

Photo Gallery

News from Centres

Chief Guest Mr. C. S. Prasad, Director General,

CPWD, New Delhi lighting the lamp

Prof. A. K. Tiwari lighting the lamp. Mr. A. K. Sharma,

Dr. Rajeev Goel, Mr. P. C. Sharma, Mr. S. Ghosh and the

Chief Guest are watching


News from Centres

AudienceEr. Vinay Gupta addressing the gathering

Dignitaries on the dias

Padmashree Dr. A. S Arya delivering his lecture Dr. Rajeev Goel welcoming the Guest

Mr. A. K. Sharma, Chief Engineer, CDO, CPWD, welcoming Mr. S. Ghosh

Selected Seminar Papers

Condition Assessment And Distress-Diagnostic TechniquesNational Conference on ‘Repair and Rehabilitation of Concrete Structures’ Organised by

Indian Concrete Institute, Western UP Ghaziabad Centre, during May 6,7, 2011 at NOIDA, INDIA

N S MoorthyDicoTech LLC, Concrete Repairs and Engineering, UAE Email: [email protected]

ABSTRACT

This paper discusses the critical requirement of the

correct condition assessment of concrete structures

and an open minded approach to assess the cause of

structural distresses and related symptoms. What is

visible to one is only the symptom. This will enable

identification of the problem in the first place. This

in turn will lead to the correct solution to the distress

of the structure. The diagnosis has to be based on

what is visible and duly correlated to the test reports

and what one perceives. There are many possible

causes that can cause a particular symptom and one

has to be methodical and logical in one’s approach

to narrow down the possibilities to arrive at the right

cause. This paper also shows some of the interesting

assessments that the author has made which do not

fall under the usual ones.

Condition Assessment

What is condition assessment? It is systematic and

logical examination of a structure to identify the

cause of the distress. The examination would cover

visual inspection, checking of documents; such as

drawings, construction records, previous investiga-

tion reports (if any), determination of the time of

appearance of the defect and analyzing the test re-

ports. Many times one would come across that many

of these may not be available! But still one has to

find ways and means of overcoming this.

Nature Of Distresses

Various kinds of distresses that we come across nor-

mally largely cover cracks (Fig.1) And the cracks

could be due to many reasons. Shrinkage cracks,

plastic shrinkage cracks, plastic settlement cracks,

early heat of hydration cracks, long term thermal

shrinkage cracks, excess stresses in flexure, tensile,

shear, punching etc. are the nature of cracks to name

a few. It could also be due to corrosion of reinforce-

ment or unequal foundation settlement.

Besides cracks, there are other symptoms of leak-

ages, seepages, discolouration and pigmentation of

concrete. i.e. stains on concrete could also lead to

important conclusions.

Fig.1 Cracks

Cracks

The first inspection to be carried out is the visual

inspection, which is the case for all the distresses ex-

plained.

Visual inspection

During visual inspection, the pattern of the crack

and the width of the cracks are to be documented

on floor plans of structure. This is called the crack

mapping. The crack mapping could be further en-

larged for better understanding for critical areas

by marking the grid both on the paper and on the

cracked structure and transfer the positions of the

cracks on to the paper. The width of the cracks is to

be measured using a crack width measuring gauge.

If both sides of the structure are accessible, it can


be checked whether the cracks are through and

through. If it is not accessible, then ultrasonic tests

are conducted to determine the depth of the cracks.

GPR (Ground Penetration Radar) could also be used

for determining the depth of the cracks.

It is also important to decide whether the cracks are

active or dormant. A glass strip fixed across the crack

(Fig. 2) shall determine the status. If the glass is bro-

ken, then the crack is active, if not it is dormant.


Fig.2 Instrument to measure the movement of crack

Cracks Remedies in brief

Let us look at the remedial measures.

1. If the cracks are at regular intervals, sometimes

even through and through, such as in a retaining

wall – inject the cracks using epoxy resin and pro-

vide control joints.

2. If the cracks are of irregular pattern such as shown

in Fig.1, it is most probably plastic shrinkage. A sim-

pler surface repair such as grouting will do (Fig.3).

3. If the cracks are wider at the top and extends only

up to the reinforcements, and mainly along the rein-

forcement then it could be due to plastic settlement.

Again grouting will do the job.

4. If it is early heat of hydration and long term ther-

mal cracks, the pattern would be the same as that of

item 1 and the treatment will be the same as well,

but with one important addition which is introduc-

tion of control joints.

5. If it is structural crack due to excessive stresses

then structural strengthening could have a number

of options including using carbon fibres.

Fig.3 Repaired Surface

6. The treatment for the cracks due to the corrosion

of reinforcement is dealt elsewhere in this paper.

But never an epoxy injection to such cracks. These

need a special treatment.

Leakage and Seepage

The second most common one is the leak (Fig.4).

Mainly in the roofs and many other water retaining

structures such as tanks, swimming pools, podiums,

dams etc.

Fig.4 Leakage of Water

Make sure that the ponded water, if any, is because

of the leaks. Sometimes this could be the water due

to washing of the floor!

Check whether it is coming through the cracks in a

clean line or else it is a damp patch. Many a times,


it could be the construction/cold joint, which is the

weakest portion for such kind of leaks. Honeycombs

could be the reason for the damp patches. Check if

there are any expansion joints that could be leak-

ing. The formation of the salt crystals due to hon-

eycombing would give an indication of the duration

of the problem. Always touch to check whether the

seemingly obvious leaking points are still leaking. At

times it would have healed by itself.

Sometimes, it could be necessary to test the leaking

water to find out the source of leakage. It could be a

drinking water line or a sewage line that has burst or

could be the ground water.

Check the quality of the concrete by visual and ham-

mer sound testing. If the structure is of poor qual-

ity and honeycombed, the possibility of the leaks to

spring elsewhere, once the existing ones are closed,

is very high.

Leakage Remedies in brief

1. If it is a crack, normally pressure injection using

Polyurethane or Acrylic resins would solve the prob-

lem. When a construction joint is treated, make sure

that the entire lengths of the joint are treated even if

the water is coming selectively in portions.

2. If it is a damp patch and the concrete is generally

good, then the choice could be between pressure in-

jection or negative waterproofing using crystalline

technologies.

3. If the concrete is porous and not of a good qual-

ity and the possibility of water to leak through else-

where, then go in for crystalline treatment without

resorting to other polyurethane or other resins (fig

5). Once the concrete is contaminated with Polyure-

thane or other resins, it would be difficult to go in for

crystallization treatment to resolve the problem.

4. Treatment to an expansion joint is done by sealing

the joint with an acrylic or polyurethane resin (injec-

Selected Seminar Paperstion yes, but not necessarily a high pressure injec-

tion) to a depth of about 10 to 15 cm and the top of

the joint is resealed by using hypalon tape.

Fig.5 Crystalline will not work if contaminated with Polyurethane

Stains, Corrosion Cracks and Spalling of Concrete

Another common problem noticed is corrosion stains

on the concrete (Fig 6). The stains are the alarm bells

to indicate that reinforcement has started corroding.

The question would remain as to at what stage of

corrosion, it is.

Look for the size of the patch. Look for any steel or

other metal fixtures nearby which could have caused

the stain and not necessarily the reinforcement.

Look for any slight bulge around the satin, which

could have been caused by the expansion of the rust

in the reinforcement. This will show whether it is

nearer to spall the concrete.

Fig.6 Strains on surface


Selected Seminar PapersHammer sounding test will show the delaminated

(but not spalled) areas, which is clear indication of

corrosion of reinforcement.

Measuring the extent of corrosion and its plotting on

floor plans is an important task to be done during

condition assessment. Half-cell potential test is the

most common one which indicates the extent and

the probability of corrosion.

Spalls

Then come the spalls (Fig.7). It is the splitting of con-

crete due the increase in volume of the reinforcing

steel because of an advanced stage of corrosion. The

corroded reinforcement gets exposed.

Visual inspection will show the extent of corrosion

spalling. In some cases one can find only the traces

of reinforcement as the reinforcement is lost due to

corrosion.

Cores are taken to determine the actual compressive

strength of the concrete and for assessment depth of

carbonation i.e. the depth of chemically deteriorated

concrete).

The powder samples of concrete are taken at vari-

ous depths by drilling to determine the chloride and

Sulphate profiles. Again this will be necessary to de-

termine the repair strategy.

Remedies in brief

• Identify the areas of corrosion stained delamina

ed and spalled concrete. Chip off the loose and de-

teriorated concrete. The chipping shall continue to

25mm behind the reinforcement and 50mm beyond

the sign of corrosion. Care shall be taken to cut the

edges of repair by at least 5mm to avoid feather edg-

ing when the re-profilation is done.

• Grit blast the corroded reinforcement to near

white metal condition.

• Apply neat polymer modified cement slurry over

the reinforcement to protect from the onslaught of

elements.

• Make sure sacrificial anodes are fixed on the re-

inforcement such as Galvashield, to avoid incipient

anodic effect.

• Soak the concrete surface to a fully saturated but

no standing water condition.

• Carryout the repair and make up the area with

micro concreting or shotcreting for the reprofilation.

The curing is a must even it is for a limited number

of days.

CASE STUDY 1: ECCENTRIC LOADING ON

THE CORBELS

This was a precast framed structure for a shopping

mall in the Middle Eat. The precast elements of col-

umns and beams with facias were designed, pro-

duced and erected by an internationally renowned

firm. The columns were erected and the beams were

placed in position on the corbels. The problem start-

ed when the structure was loaded with the façade

panels. Almost all the corbels cracked (Fig.8) and the

construction was stopped.

The visual inspection showed that the cracks have

opened at the top and narrowed as it went further

down. So it is a crack caused due to flexure on the

corbel. The load transmission was by a kind of point

load through the shims kept in position to adjust the

levels during erection. The point of transmission of

Fig.7 Spall of Concrete


load appeared to be more towards the edge of the

corbel. So, this was an error of erection. But that was

not the only error that happened. When the precast

elements were produced in the factory, a steel plate

was embedded in the corbel to indicate the erection

crew, the locations of the leveling shim for the beam.

The placement of the beams was wrong. So the pro-

duction could be wrong. But not really. The produc-

tion follows a shop drawing which indicates clearly

where the embed had to be placed. The original mis-

take has happened with the draftsman who had put

in a wrong dimension.

Remedy

The owner wanted the structure to be rebuilt by the

contracting company as he did not want to take any

chances with the safety of the public who would be

using the shopping mall. The contractor was reluc-

tant to go in for reconstruction. So a solution had to

be found out.

The beams were slightly jacked up to relieve the cor-

bels from the loads. The existing cracks have been

sealed by pressure injection. The joint between the

corbels and the beams were sealed. An epoxy resin

with 100% solids was injected at low pressures to

create a solid and uniform bed to distribute the load

over a large area. Once the epoxy resin was cured,

the beams after its structural retrofitting and shift-

ing the loading point to safer turfs, were allowed to

rest. The structure is still standing after 20 years of

this operation.

Fig.8 Repair of cracked corbels

CASE STUDY 2: CRACKS IN THE PEDESTALS

OF FLUE TUBE

It is a case of a power generating station. The tur-

bines were seated on heavy foundation pedestals.

The flue tube which was about a meter dia was also

resting on two pedestal foundations. The power sta-

tion was stopped after 100hors of commissioning due

to cracks developed on the flue tube pedestals and

also the grout bedding under the foundation plate

had turned black. Despite re-doing the grouting and

injecting the crack, the problems again resurfaced

after running the turbines for another 100 hours or

so. That was when the problem was referred. The

second problem of grout bleeding under foundation

plate was easier to identify. An epoxy grout had been

used under the base plates. But the epoxy grout had

a limitation of higher temperatures more than 70c.

The flue gas temperatures which can reach sever-

al multiples of this have obviously burnt the epoxy

grout. It was suggested that a cementitious grout of

high compressive strength shall be used instead of

an epoxy grout. But the cracks on the pedestals were

a bit challenging. The cracks have started at the an-

chor bolt points and wider at the top and narrower as

it went down. So it was the lateral pressure exerted

on the anchor bolts that could have been the reason.

This pressure could come only from the movement

of the flue tube. But it is designed for movement.

There are two base plates one on top of each other.

The top plate is rigidly fixed to the flue tube while

the bottom one is fixed to the pedestal. The interface

between the plates is to be greased to facilitate the

movement. It was out in the site that it was not so

and grease port was even blocked. Hence, it was ad-

vised that the ports are greased periodically and the

repairs for the cracks were carried out.

Fig.9 Schematic layout



CASE STUDY 3: LEAKAGE IN BOMB SHELTER

Bomb shelters are structures where the fighter

planes are parked for protection against the debris

due to bombs and its explosion. The structure is

parabolic with 50cm of sand encased by concrete

on both sides. The thickness of the concrete casing

was 1m external and 50cm internal (Fig.10) There

was water leaking through the expansion joints like

coming out of a tap. So the first checking to be done

was all the plumbing lines. But the lines showed no

drop in pressure which showed that the plumbing

was not the reason.

The roof had an expansion joint which was sealed

by a polysulphide mastic sealant. The joint width

was about 10cm (!) as against the 20mm designed

(Fig.11).

The polysulphide sealant had given way and in many

places come off the sides of the concrete. Whenev-

er there had been rain in that area, the rain water

has gone in and collected in the voids of the sand

cushion in-between the concrete casings. Even after

3 months after the rain has stopped, the collected

water was coming out of the expansion joints by the

sides. The collected water around the bunker has

caused heightened ambient relative humidity. This

in turn and in course of time started the corrosion

of the reinforcement. The concrete started splitting

and the bomb shelter faced the bleak prospect of

falling apart without bombs (Fig.12).

The only remedy was sealing of the expansion joints

on the top, but this time using a hypalon tape system

which is suitable for higher joint widths. The expan-

sion joints at the sides were injected with polyure-

thane resin to stop the water and the joints sealed

with hypalon tape system.

CASE STUDY 4: LEAKAGE THROUGH JOINTS

This was a discharge channel in the process area in a

petrochemical plant. The discharge was a combina-

tion of EDC (Ethelene di Chloride) and Hydrochlo-

ric acid. The discharge had started leaking through

the damaged joint sealants (Fig.13) and into the soil.

There was a pump and compressor area nearby. The

EDC which has gone into the soil had eaten away the

construction fillings under the pump foundations

and the area started to settle down. The situation

was alarming and it might cause the shutdown of the

plant. The existing sealant was good enough to resist

the combination of this chemical. But it was not elas-

tic enough to resist the movements of the channel.

The expansion joints have given way and hence the

leakage. The requirement of the client was a seal-

ant that shall resist 100% concentrated EDC and a

15% concentration of HCL both combined at a tem-


Fig.10 Schematic View of Bomb Shelter

Fig.11 Schematic View of failed expansion joint

Fig.12 Schematic View of damaged concrete


perature of 100oC. The material suitable to resist

EDC, would not resist HCL and vice versa. Even

with a material able to resist both then, the tem-

perature was a problem. If all these conditions were

satisfied then it was not flexible enough which could

Selected Seminar Papersbe laid in the channel to remain in good shape.

The finding and the subsequent thought pro-

cess made the team to invent a joint sealant using

non-elastomeric HDPE to take the expansion and

contraction and also to not to give way.

Fig.13 Schematic View of Channel and failed expansion joints

CASE STUDY 5: CRACKS IN CAR PARK

The car park was of 4 levels and the main contrac-

tor was in the process of handing over. But was not

able to, because there were cracks developed in the

ramps (Fig.14). When checked, something peculiar

was noticed. The cracks were in the ramps in a kind

of regular intervals. But the ramps in the opposite

side of the car park floor did not have any crack! All

these were done by the same company and at the

same time.

Fig.14 Schematic view of Cracked Locations

But why on one and why not on the other? One

side of the car park had a mosque, which was of low

height and plenty of space around. But on the other

side there were high rise buildings. The Sun was

shining on the car park on the mosque side and was

shaded constantly on the other side. The result: the

ramp on the mosque side was subjected to height-

ened temperature variations, whereas the other side

was relatively stable.

Having solved the puzzle, the remedy given was to

inject the cracks with rigid epoxy resins but cutting

out control joints to take care of the movements.

CONCLUSIONS

An assessor would find that many times the cause

of distress could be found by methodical and logical

derivations. But some times what one sees and as-

sumes is not what it is. That was why an emphasis

has been made to keep an open mind when one goes

for a condition survey. It is always good to remem-

ber not only to look at the structure but look its sur-

roundings. One has to look for the basic reasons that

might have caused the distress. Such as when a roof

is leaking, just unblock the drains. This will save the

problem of roof leakage and save lot of money to the

owner.


ABSTRACT

In the modern era, fire is one of the unpredictable,

but common causes of accidental damage of indus-

trial structures. Reinforced concrete Structures

though less susceptible to structural damage to an

extent of Steel Structures are also damaged and may

require large repairs depending upon the duration

of fire and temperatures attained during the same.

The investigation to assess the damage to concrete

and steel members is tedious and requires addition-

al help of concrete petrographers. A combination of

non-destructive test tools along with chemical and

micro structural investigation is required to assess

the damage to structural elements before preparing

the repairrehabilitation programme for the struc-

ture. The papers details the methodology adopted

for investigation, assessment of structural health

and reliability of various test for investigation of a

fire damaged structure.

Keywords: fire, temperature, petrographers, micro-

structural

INTRODUCTION

When reinforced concrete is subjected to high tem-

perature as in fire, there is deterioration in its prop-

erties. Of particular importance are losses in com-

pressive strength, cracking and spalling of concrete,

destruction of the bond between the cement paste

and the aggregates and the gradual deterioration of

the hardened cement paste.

Assessment of fire-damaged concrete usually starts

with visual observation of color change, cracking

and spalling of the surface. Concrete color provides

a broad, general guide of temperatures, whether the

color represents the original surface or one result-

ing from spalling. Crazing, cracking popouts caused

by quartz or chert aggregate particles, spalling and

dehydration (crumbling and powdering of paste) are

general indications of temperatures to which con-

crete has been exposed as shown in Fig.1. On heating

above 300 °C the color of concrete can change from

normal to pink (300–600 °C) to whitish gray (600–900

°C) and buff (900–1000 °C). The pink discoloration re-

sults from the presence of iron compound in the fine

or coarse aggregates [1, 2 and 3].

The first effects of a slow temperature rise in con-

crete will occur between 100 and 200 °C when evapo-

ration of the free moisture, contained in the concrete

mass, occurs. Instant exposure can result in spall-

ing through generation of high internal steam pres-

sures. As the temperature approaches 250 °C dehy-

dration or loss of the non-evaporable water or water

of hydration, begins to take place. The first sizable

degradation in compressive strength is usually expe-

rienced between 200 and 250 °C. At 300 °C strength

reduction would be in the range of 15–40%. At 550 °C

reduction in compressive strength would typically

range from 55% to 70% of its original value [3, 4 and

5].


Diagnosis of Fire Damaged Industrial StructureNational Conference on ‘Repair and Rehabilitation of Concrete Structures’ Organised by

Indian Concrete Institute, Western UP Ghaziabad Centre, during May 6,7, 2011 at NOIDA, INDIA

Ashok Kumar TiwariVice President ( North) Indian Concrete Institute

Email: [email protected]

Fig.1 Visual evidence of temperature to which concrete has been heated


Selected Seminar PapersTemperatures in the 550 °C range are critical because

calcium hydroxide dehydration takes place. Calcium

hydroxide is a hydration product of most Portland

cement, the amount being dependent upon the par-

ticular cement being used. Aggregates also begin to

deteriorate at about 550 °C. For example quartz ex-

pands at a higher rate around 300 °C [6 and 7].

Two main types of spalling occur during fire. Explo-

sive spalling and sloughing off of concrete surface

layers. Explosive spalling looks like a series of pop-

outs and usually occurs within the first 30 min of

fire-exposure. Sloughing off is a gradual non-violent

separation of the concrete that occurs primarily at

the edges of columns and beams. When concrete

spalls, deeper layers of concrete are exposed to the

maximum fire-temperature, speeding the transmis-

sion of heat to the reinforcement. As the temperature

within a member rises, steel reinforcement expands

more than concrete. This can lead to further spalling

and cracking around the steel. Such cracks often de-

velop where incipient cracks (due to drying shrink-

age, flexural loading or other factors) were present.

Also, differing thermal expansion between aggre-

gates and cement paste can create surface crazing,

which can lead to deeper cracking [4 and 7].

INDUSTRIAL BUILDING-CASE STUDY

The building constructed is a composite structure

consisting of RCC frame, a steel column and some

external load bearing walls housing R & D centre

and office space. It is reported that the building

was earlier used as industrial building and only few

years ago, it was converted to office cum R & D

building. The structural layout of the building is

bit complex and seems a number of extensions to

building were affected since its inception. The

external columns are spaced at 3.3 m span and

longest beam spans to 8.5 m. There are four slabs

in office area and two in R & D area. The structure

was constructed in 1965 and none of the structural

drawings are available.

It is learnt that the structure caught fire after office

hours at about 7.30 PM on Friday, March 22, 2002.

The fire was brought under control by around 2.30

AM in night.

Investigation For Fire Damage

A detailed visual inspection of the building and the

following Non-destructive tests (NDT) at

select locations were carried out to assess the extent

of fire damage on building RCC structure.

The results of NDT are provided in the form of ta-

bles.

• Schmidt Hammer test

• Ultra-sonic Pulse Velocity (UPV)

Also, concrete core samples, concrete chunks and

reinforcement bars were collected from different lo-

cations and were analyzed for the following at labo-

ratories;

• Compressive strength tests

• Chemical properties like pH, Chlorides and

Sul phate

• Differential thermal analysis

• X-ray diffraction

• Yield strength, weight loss and elongation of

rebars

Visual Inspection

The building was visually inspected and a structural

layout of building was prepared, as

shown in Fig.2. The following are the main observa-

tions of the Visual Inspection Survey:

1. The concrete elements viz., columns, beams and

slabs are severely affected by fire on some of the

floors.

2. The damage due to fire on ground floor is almost

negligible excepting discolorations of surfaces

due to smoke.

3. Most of the structural elements, in office area

were severely damaged due to fire showing

spalling, cracking at the surface of elements.


Selected Seminar Papers4. The damage due to fire on IV floor seems to be

ngligible except discolorations of surfaces due to

smoke.

5. Severe damage of many columns and slab bo

toms of first, second and third floor due to

fire was observed in the form of cracking,

spalling, and colour of concrete turning to whi

ish brown.

6. Deflection of longest span beams at all three

floors were measured to find the effect of fire

on steel reinforcements. The measured defle

tions are given in Table 1.

Fig.2 TGA scan for First floor Column A5, depth 100 mm

Non-destructive test results

Impact Hammer Test

The Schmidt hammer test was done at select loca-

tions of the building and results were found to be

highly variable due to surface condition. The test

was discarded for the present evaluation, as rebound

hammer tends to give higher values for carbonated

surfaces and variations are high.

Ultra-sonic Pulse Velocity Test

The ultra-sonic pulse velocity measurements were

taken at select locations of the building to see the

soundness of concrete on unaffected elements /por-

tions and also on fire affected elements. The results

are provided in Table 2. The criteria for qualitative

assessment of the concrete quality is based on ARE

code. The results reveal that the ultra-sonic pulse

velocity more than 3.5 km/sec taken at undamaged

areas indicates good quality of concrete. The very

poor velocities or no sound wave transmission at fire

damaged locations could be due to cracks and/or sig-

nificant damage of concrete.



Core Test

The concrete cores were extracted from select loca-

tions of the building from damaged and undamaged

concrete elements. Please note that cores were bro-

ken during extraction up to 100 mm from surface in

the fire damaged concrete elements. It clearly shows

that severe damage due to fire has occurred. The

cores collected from undamaged concrete elements

were tested at the RCD laboratory in Thane. The re-

sults of core test are tabulated in Table 3.

The results reveal that the concrete strengths

obtained from core testing are satisfactory for M15

grade (1:2:4) concrete used in the construction.

Test on Rebar samples

The Reinforcement bars were collected from select

fire damaged RCC members of the building and

were tested for strength, weight loss and elongation.

The results are tabulated in Table 4. The results with

respect to IS code are unsatisfactory.

Analysis of concrete

Chemical analysis

The chemical analysis of the concrete samples, for

Chloride content, Sulphate content and pH of con-

crete, prepared from the concrete cores collected

from select locations of the structure was carried

out. The identification of sample taken for chemi-

cal analysis and the results are provided in Table 5.

Chloride content in all samples is lower than the lim-

iting value of 0.4%. Sulphate content of all samples is

also less than the limiting value of 3%.

The pH value is below 10.5 in all cases of samples

tested indicating that the alkalinity of the concrete

has gone down in concrete. The pH values less than

10 shows high degree of loss in Ca(OH)2 due to fire

even up to a depth of 100 mm from the surface of

concrete.

Differential Thermal Analysis (DTA) &

Thermo-gravimetric Analysis (TGA)

DTA and TGA techniques are employed for the

qualitative and quantitative estimation of the com-

pounds present in the concrete samples. The tech-

nique involves heating up of the sample under con-

sideration and thermal behaviour is observed which

is related to the identification of compounds actually

present and comparing with similar sample which is

not subjected to fire. The Differential thermogram

of concrete sample exhibits endothermic peaks in

different temperature ranges and these ranges are

generally attributed to certain parameters as given

in Table 6 below:



Selected samples taken from cores and concrete

chunks have been subjected to DTA/TGA to study

the thermal behaviour of concrete. A few typical

scan of DTA and TGA are given in Fig.2 and Fig.3.

The results reveal that many samples taken at vary-

ing depths up to about 100 mm from surface show

low or zero weight loss. It can be said that these sam-

ples taken from the severely damaged members are

already exposed to temperature more than about

5000C and concrete has lost most of its strength. In

addition the passivity of concrete to rebars against

corrosion is almost completely lost in the absence of

Ca(OH)2.

Fig.3 TGA scan for Second floor Column E5, depth 100 mm

X-Ray Diffraction (XRD)

In the XRD technique, the characteristic diffraction

lines of each micro-crystalline cementitious phases

and their hydration / degradation products are com-

pared with the standard mineral phase samples and

the degree of variation in terms of intensity, shape

and position of these lines is considered for identifi-

cation /evaluation purpose.

Selected samples prepared from cores and concrete

chunks have been subjected to XRD analysis. The

presence of Calcium hydroxide (Ca(OH)2) found

from XRD analysis in the form of counts is given in

Table 7. The results are supportive to DTA. A few

scans are shown in Fig.4 to Fig.7.

Fig.4 XRD scan sample from Second floor Column E5, depth 100 mm

Fig.5 XRD scan of sample from first floor column G2

Fig.6 XRD scan of sample from first floor beam 5-5



Fig.7 XRD scan sample from First floor Column A5, depth 100 mm

CONCLUSIONS

The following observations are made in the evalua-

tion of the building:

1. Building is about forty years old and reinforc

ments are heavily corroded, lost cross-sections

and fails in ultimate tensile strength specific

tions. All the reinforced bars tested are found to

be unsatisfactory.

2. Fire has penetrated into concrete beyond the

cover to rebars, reaching the core of most of the

columns.

3. Due to loss of Ca(OH)2 from concrete cover, con-

crete will no longer be able to protect rebars from

corrosion.

4. The concrete has become brittle and quality is

unsatisfactory even though some cores show sat-

isfactory strength levels.

5. In R & D building, main beam seems to be resting

on end steel column, which must have lost its ten

sile strength heavily.

RECOMMENDATIONS

Based on the investigation, it is recommended here

that all floors of building, except ground floor shall

be dismantled.

ACKNOWLEDGMENTS

The reported case study has been a consultancy proj-

ect by the author in capacity as Head of Concrete

Technology Group at ACC Limited. The acknowl-

edgement is due to the management and working

group at the company along with manag ment of Ex-

cel Industries, Mumbai.

REFERENCES

1. B. Erlin et al., Evaluating fire damage to concrete

structures. Concrete Construction 2 (1972),

pp. 76–82.

2. J.K. Green, Reinstatement of concrete structures

after fire. The Architects’ J 1 (1971), pp. 93–99.

3. Guise SE. Petrographic and color analysis for a

sessment of fire damaged concrete. In: Jany L,

et al., editor. Proceedings of the 19th International

Conference on Cement Microscopy. 1999. p.

365–72.

4. L. Powers-Couche, Fire damaged concrete-up

close. Concrete Repair Digest 1 (1992), pp.

241–248.

5. Gustafero AH. Experiences from evaluating fire

damaged concrete structures––fire safety of con-

crete structures. American Concrete Institute

SP-80, 1983.

6. Chu TY. Radiant heat evaluation of concrete––a

study of the erosion of concrete due to surface

heating. Research Paper Sand 77-0922. Sandia

Laboratories. Albuquerque Nm, 1978.

7. Powers-Couche L. observations of concrete e

posed to very high temperature. In: Gouda Gr. et

al, Editor. Proceedings of the 16th International

conference on cement microscopy. 1994. P.

369–76.

8. Georgali, B. and Tsakiridis, P. E., Microstructure

of fire-damaged concrete. A case study , Cement

and concrete composites Volume 27, Issue 2 , Feb-

ruary 2005, Pages 255-259.

9. Tiwari, A. K., Structural assessment and repair

of fire affected buildings, The International Con-

ference on Concrete Repair, Rehabilitation and

Retrofitting, Cape Town, South Africa, November

2005.

10. Concrete Society, Assessment, Design and R

pair of Fire–damaged Concrete Structures, Tec

nical Report No. 68, December 2008.



MBM Engineering College, Jodhpur

MBM Engineering College, Jodhpur organized

a three day symposium “ADCON 2011” between

28th and 30th April 2011. It was a National Level

Deminar on ‘Future Sustainable Concrete” with a

talent inquest for civil engineering students. Manu-

facturers demonstrated their latest product during

this event. Prof. S. S. Sankha was the Adviser and

Mahipal Burdak was the co-ordinator for the whole

programme. The first day key-note address was

delivered by Er.Prakash Sharma on ‘Correct Step

for Concrete Making’. On the second day of the

Deminar there was a competition in paper

presentation for students in which Charu Mittal was

the winner. This was followed by a quiz competition

in which teams of Prem Kumar and Sukhdeep Singh

were declared as winners.

Students took a site visit to a sewage treatment plant

at Salawas and Dr. S. K. Singh guided the tour. They

also visited AIIMS Jodhpur Hospital construction

site, a concrete testing laboratory and a batching

plant at the construction site. Prof. P. K. Agarwal

RTU Kota briefed on the High Performance Con-

crete and Self Compacting Concrete.

On the last day, Prof.Agarwal spoke on Use of Fly

Ash, its Microstructure and other mechanical and

chemical properties in making the concrete. Prof.

Bupendra Singh, IIT Roorkee presented a case study

on DMRC Project Pier Failure. Prof. A. K.Gupta

discussed on ‘Field Failure Reasons’ and stressed

on the Importance of Workability and Workman-

ship. Prof.B.Singh presented a case study on ‘JLN

Stadium’ and ‘CWG Foot Bridge Failure’. Er. Rajesh

Kumar, Zonal Head, Ultra Tech Concrete shared

his views on RMC and Value Added Concrete and

explained the importance of safety at Construction

Site.

Lectures, Video Presentations, Demonstration of

Equipments, Site Visits and Talent Quests were the

highlights of the event which was informative and

interactive.

Opening ceremony of ADCON 2011 Chief Guest Prof. Dr. Naveen Mathur &

other participant

ICI Students Chapter



Lecture by Er. Prakesh Sharma Er. M. Khursid and Er. R. Ganeshan explaing to students.

Site Visit guided by Dr. S. K. Singh

Prof. S. S. Sankhla guiding the students

Students participating in Talent Quest

Lecture by Prof. P. K. Agarwal



Lecture by Prof. Bhupendra Singh Lecture by Er. Rajeeb Kumar

Organisers with Chief Guest at valedictory function.

Tariff For advertisement

Full page color inside pages

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1. Inauguration of New ICI Students Chapter

1. ICI Student Chapter of Global

Academy

ICI-Student Chapter-Global Acade-

my of Technology was inaugurated on

Thursday 28th April 2011 by Mr.Vijay

R.Kulkarni, President ICI in the pres-

ence of Dr .C. S. Viswanatha, Chairman,

CTPL. & Chairman, Taskforce for Qual-

ity Control, Bangalore.

Mr. Vijay R. Kulkarni, in his inaugural

address, provided full information on

present state of construction industry in

the country and the associated umpteen

opportunities which are available for

Civil Engineers.

Mr. Rajkumar Pillai, Chairman, ICI,

Karnataka Bangalore Centre spoke on

the importance of integrity and hands-

on experience as mandatory ingredients

for young engineers for the success in

any profession.

Mr. M. S. Sudarshan, Vice Chairman,

Civilaid Technoclinic (Pvt) Ltd. stressed

upon the need for Industry Institute In-

teraction and explained the efforts on

the part of CTPL to bridge industry and

academia for mutual benefit and society

wellbeing.

Dr. Narendra Viswanath, Principal, Glob-

al Academy of Technology welcomed the

gathering. The programme was success-

fully organised by the students under

the leadership of student Coordinators

Pramod. M., Amey Gudigar and Pavan P.

of VI Sem. Civil Engineering under the

guidance of Dr.C.V.Srinivasa, Professor

and Head, Department of Civil Engi-

neering, and Bharathi Ganesh, Assistant

Professor, ICI Coordinator, GAT.

Inauguration of GAT-ICI Student Chapter

Dr. M. R. Kalgal giving away the Certificate of Merit to students

Dignitaries during the Student Chapter Inauguration


2. SRM University, NCR Campus, Modinagar

Student Chapter of SRM University, NCR Campus,

Modinagar was inaugurated on 8th May 2011.

Prof.K.S.Raja, Asst. Professor welcomed the gather-

ing. Prof.A.K.Tiwari, delivered a lecture on “Various

Aspect of Civil Engineering”. Following this office

bearers of the Student Chapter were introduced.

Dr. Gajanan M. Sabnis alongwith Dean, SRM Uni. and Prof. A. K. Tiwari lighting lamp

Dignatries alongwith students and faculty of SRM University

Prof. A. K. Tiwari receiving bouquet from Dr. Vineet Bajaj, H.O.D., Deptt of Civil Engg.

On this occasion, Dr.Gajanan M.Sabnis who was the

Chief Guest, gave a special lecture on ‘Green Con-

crete’.

The programme ended with vote of thanks by Prof.

M. K. Pandey, Dean, SRM University.

Office-bearers of the student chapter




Forthcoming Events ICI-Pune centre is Organising a seminar under the banner of CEMCON 2011 on “Construction of Highrise

Building (Above 100 M)” on 17th and 18th June 2011.

For details, pl contact :

CEMCON 2011, c/o Arkey Engineering, Prabhat Road, Pune 4. Tel : 91-20-25670808, Fax: 91-20-25672555,

25676767. Email: [email protected], [email protected].

New MembersIndividual

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