Aluminium Formwork

Aluminium Formwork SCOE.

ALUMINIUM FORMWORK

ABSTRACT

A form work system with acrow spans, steel adjustable props

by using either steel plates or film coated plywood with runner beams of well seasoned

wood is widely used in construction in many urban housing projects in our country. This

traditional or conventional method of construction for mass housing is comparatively, a

slow process and has limited quality control, particularly when a large size project is

involved. It is therefore obligatory to work out a method or a scheme where the speed and

quality of construction are controlled automatically by a systematic approach. To bring

industrialized, assembly line approach in mass housing projects – ‘Aluform System’, is

successfully implemented in many countries. This system is recently introduced in few

mass housing projects in India. And it is comparatively found to be more economical and

suitable for our mass-housing programme in urban areas where 4-5 storeyed construction

is quite common for better utilization of expensive land.

Due to very high investment involved in Precast Factory, ( as

heavy investment in the plant & machinery and subsequent dependence on imported

equipment and spares ) ‘Large Precast Panel System’ has not become so common in

India. Aluform System involves less investment compared to Precast Factory and still has

the advantages of speedy & sound construction, in addition to the reduced labour cost of

Finishing Items.

Aluform is a construction system for forming cast in place

concrete structure of a Building. Aluform System provides aluminium form work for

RCC load-bearing multi-storeyed buildings and enables the walls and slab to be poured in

the same operation. This increases efficiency, and also produces an extra-ordinarily

strong structure with excellent concrete finish.

In this report, Aluform System is described in detail with its

advantages and limitations, case study and also the comparison with conventional form

work system. Authorities entrusted with execution of mass housing programmes in urban

areas may consider this system for future construction.

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INTRODUCTION

Aluform is a construction system for forming cast in place concrete

structure of a Building. Aluform system provides aluminium form work for RCC load-

bearing multi-storeyed buildings and enables the walls and slab to be poured in the same

operation. This increases efficiency, and also produces an extra-ordinarily strong

structure with excellent concrete finish.

Due to the fine tolerances achieved in the machined metal form work

components, consistent concrete shapes and finishes are obtained floor after floor,

building after building, confirming to the most exacting standards of quality and

accuracy. This allows plumbing and electrical fittings to be prefabricated with the certain

knowledge that there will be an exact fit when assembled. The dimensional accuracy at

the concreted work also results in consistent fittings of doors and windows. The smooth

off form finish of the concrete eliminates the need for costly plastering.

The system of Aluminium Forms has been used widely in the

construction of residential units in both low-rise & high-rise buildings. It has proven to

be very successful in the construction of mass housing projects in various parts of the

world. The system most suitable for Indian conditions is a tailor-made aluminium form

work for cast-in-situ fully concrete structure. It is also a system for scheduling and

controlling the work of other connected construction trades such as steel reinforcement,

concrete placement and mechanical & electrical inserts.

The form work system is unique because it enables the construction of

the entire structure of a building in R.C.C. with all the members including walls, floor

slabs, window hoods, balconies, sunken floors and various decorative features, being cast

integrally for each floor as per the architect’s requirement.

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COMPONENTS OF ALUMINIUM FORMWORK SYSTEM

Fig. No. 1 – Isometric View of the Aluminium Form

The aluminium form work comprises of the hardware and software as, in any other

engineering system. The hardware consists of a large number of standard pieces of

form work equipment, manufactured to fine tolerances. The majority of the equipment

comprises of panel sections while the rest includes vertical and horizontal corner

sections, bulkheads and special floor slab beams as shown in Fig. No. 1 that can be

dismantled without disturbing the props supporting the floor slab concrete. All panels

are numbered with a code in different colours, which determines its predetermined

location. Proper coding saves time and the work can be done speedily.

The light weight of aluminium forms which can weigh as little as one

third of their steel equivalent opens the way to greatly increased site acceptance and

productivity. Nearly 99 percent of the equipment is made of aluminium, the other one

percent is steel. The use of aluminium allows larger components to be big enough to be

effective, yet light enough to be handled by a single worker. For example, the largest

panel of about 500 mm width and floor to ceiling height weighs not more than 30 kg.

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DIFFERENT PARAMETERS OF THE ALUFORM SYSTEM● General Features :

1) Versatility :-

Architect is not required to change the building layout to suit the technology.

Capable of forming any type of structural design.

The System is unique in that it forms all of the concrete in a building including;

walls , columns , beams , floor slabs , staircases , balconies, window hoods , storage lofts.

No need for bricks, blocks or plastering.

2) Speed :-

Multi-Storey Housing - structures are completed at the rate of four days per floor -

regardless of floor size.

Thousands of tenements can be completed annually.

3) Quality :-

Precision in fabricating the form work results in accurate and consistent forming of the

concrete. The quality of the concrete finish is the same regardless of whether the system

is used for low cost housing or luxury housing.

4) Durability :-

Two issues related to durability; – durability of the housing units,

– durability of the aluminium form work

i) Durability of the housing units :-

All concrete (walls, slabs, staircases etc.) are poured monolithically, therefore, there are

no construction joints and no problems of leaking joints.

Smooth concrete finish means that no plastering is required. The tendency of plastering

to break away is well known.

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All four walls in a room, as well as the floor and ceiling, are cast-in-place reinforced

concrete. The result is a rigid reinforced “box” structure, which has no joints and is very

durable.

ii) Durability of the aluminium form work :-

Formwork is made with an aluminium alloy, which has high tensile strength and is also

very hard. Aluminium does not rust like steel; therefore, the aluminium form work can be

re-used hundreds of times. Aluminium being lightweight is easy to handle.

5) Cost :-

The System is so Cost Effective because –

Highly reusable form work

Forms all the concrete in a building.

Unique construction cycling.

Uses local building materials.

Requires unskilled labour only and no cranes.

Load bearing wall structural design.

COST ASPECT

For 1 sq. ft. of plan area about 4.0 sq. ft. of form area is required.

Approximate cost of form work is Rs. 1000 / sq. ft. of form work area.

● Costing : Data For Costing

Total Buildings 15Total Floors in One Building 11Area of One Floor 4500 Sq. ft.

i.e. 420 Sq. m.Total Formwork Equipment 1570 m2

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Table No. 1 Costing For Locally Manufactured Formwork

Sr. No.

Item Figure

1. Cost of Aluminium Formwork per Sq. m. Rs. 10,0002. Cost For 15 Buildings

( Built-up area = 69300 Sq. m.)1570 X 10,000= Rs. 1,57,00,000

3. Interest For 2 years @ 15 % Rs. 47,10,000

4. Total Cost Rs. 2,04,10,000

5. Cost per Sq. ft. of Built-up area( Built-up area = 15 X 11 X 4500 = 742500 Sq. ft.

2,04,10,000 / 742500= Rs. 27.50

Table No. 2 Comparison of Labour Cost

Sr. No.

Description Aluform Conventional System

1.

2.

3.

4.

Shuttering Work

Reinforcement Work

Concreting

Masonry and Plastering Work

Rs. 17 / Sq. ft.

Rs. 10 / Sq. ft.

Rs. 4.50 / Sq. ft.

****

Rs. 12 / Sq. ft.

Rs. 7 / Sq. ft.

Rs. 2.50 / Sq. ft.

Rs. 28 / Sq. ft.

Total Rs. 31.50 / Sq. ft. Rs. 49.50 / Sq. ft.

Table No. 3 Overall Comparison of Imported Formwork

Sr. No.


1.

2.

Cost of Shuttering Material

Labour Cost

Rs. 57.00 / Sq. ft.

Rs. 31.50 / Sq. ft.

Rs. 20.00 / Sq. ft.

Rs. 49.50 / Sq. ft.


Table No. 4 Overall Comparison of Locally Manufactured Formwork

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From the tables it is clear that Locally manufactured form work is cheaper than

imported form work This is the reason to promote the design, development and

manufacturing of aluminium form work in India.

The table no. 2shows the comparison of Labour Cost. So it will be clear

that the labour cost for Aluform System is less than the conventional system because

Masonry and Plastering Cost is totally eliminated.

From the table no.3 it will be seen that the total cost of Aluform System

is greater than conventional system. But still for mass housing Aluform System proves to

be economical than conventional system because of great speed, good quality and

repeated use.

The table no. 4 shows Overall Comparison of Locally Manufactured

Formwork. And now there is a great saving in total cost than imported form work Also

the total cost is less than the conventional form work system. Therefore, for mass housing

Aluform System proves to be very economical and ideal than conventional form work

system particularly when form work is locally manufactured.

ADVANTAGES, LIMITATIONS AND

APPLICATIONS

● Specific Merits of the Aluminium Formwork System :

1. Less use of skilled labour and heavy machinery

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Sr. No.


1.

2.

Cost of Shuttering Material

Labour Cost

Rs. 27.50 / Sq. ft.

Rs. 31.50 / Sq. ft.

Rs. 20.00 / Sq. ft.

Rs. 49.50 / Sq. ft.


Handling of panel by a single worker


In contrast to most of the other modern construction systems, which are machine and equipment oriented, this system does not depend upon heavy lifting equipment or even skilled labour. Equipment can be handled by trained unskilled labour. The heaviest component weighs not more than 30 kilograms, which means that even a single worker can handle it with ease. The panels and other sections are secured and fixed by steel pins and wedges with spacer ties. The only tool required for assembling and dismantling is a hammer. 2. Speed of construction

Fast construction is assured and is particularly suitable for large magnitude

construction of repetitive nature at one project site. All panels are clearly labeled to

ensure that they are easily identifiable at site and can be smoothly fitted together using

the form work modulation drawings.

In view of the four-day cycle of casting the floor together with all slabs as

against 14 to 20-day cycle in the conventional method, completed RCC structure is

available for subsequent finishing trades much faster, resulting in a saving of 10 to 15

days per floor in the overall completion period.

3. Quality of Work

Construction carried out by this system

has exceptionally good quality with

accurate dimensions for all openings to

receive windows and doors, right angles at

meeting points of wall to wall, wall to

floor, wall to ceiling, etc. Concrete surface

finishes are good to receive paint directly

without plaster. Monolithic construction of

load bearing walls and slabs in concrete

produces structurally superior quality with

very few construction joints compared to

the conventional column and beam slabs construction combined with filler brick work or

block work subsequently covered by plaster.

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Superior Quality of Construction


4. Repetition of form work

System components are tough, durable and rigid and can be used several times

without sacrificing the quality or correctness of dimensions and surface. The corrosion

resistance of aluminium ensures the long maintenance free life, further extended by the

fact that it cannot be easily cutup on site like timber beams.

5. Flexibility of System

Unlike the moulds for large panel Precast construction the form work for this

system can be designed for small cluster of houses of 400-500 units. Hence the system is

more flexible to accommodate modifications for changes in layout or different elevation

treatment for different shelter, which is not possible for factory made pre-cast panel,

where size of project has to be at least 1000-1500 units to make it economically viable.

6. Simplicity

The panel fits precisely, simply and securely and requires no bracing. Once the

panel have been numbered measuring is not necessary. As the erection can be carried out

manually, tower cranes are not required and can concentrate on the other handling

operations.

7. Efficiency

The quick strip prop head, one of the principle technical features which enables

the speed to be attained using a single set of form work panels, is the unique 'v' shaped

prop head which allows the quick strip to take place whilst leaving the propping

undisturbed.

Limitations of Aluform System :

1. Architectural changes are not possible in the structure ( but some walls can be of brickwork or openings can be entertained ).2. Due to the tremendous speed of construction, working capital finance needs to be planned in advance.3. Superior quality paint is required.

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Application

Nagari Nivara Parishad Housing Project, Mumbai.

No. of Housing Units :- 3600

Total Built-up Floor Area :- 144750 sq. m.

Total Concrete Forming Area :- 698700 sq. m.

Formwork Equipment Used :-

Horizontal – 1180 sq. m. Vertical – 1970 sq. m. Total – 3150 sq. m.

Nagari Nivara Parishad Housing Project (Type: LIG 3600 units)

Mumbai

CASE STUDY

Project :- Sylvan Heights, Aundh, Pune.

Architect :- Naiknavare & Associates

Structural Consultant :- Naiknavare & Associates

Builder :- Naiknavare & Associates

Type of Construction :- R. C. C. Load Bearing Construction

Month of Commencement :- May 2002

Proposed residential building ( Sylvan Heights ) construction work is going

on at Aundh, Pune. The details of the project are as follows –

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Sylvan Heights / Imperial Residency, Pune.

No. of Buildings :- 15 ( stilt + 11 storeyed )

Total Built-up Floor Area :- 69000 sq.m.Total Concrete Forming Area :- 345000 sq. m.

Sylvan Heights, Naiknavare & Associates [660 HIG Units]

Formwork Equipment Used :-

Horizontal – 400 sq. m.

Vertical - 1170 sq. m

Total - 1570 sq. m.

Suitability of the Aluform system for this project :-

The traditional or conventional method of construction for mass

housing projects is a comparatively slow process, labour dependent and has limited

quality control, particularly when large size projects are involved. So the Aluform

System, which is identified, to be suitable for Indian condition for mass housing

construction where quality and speed can be maintained at a reasonably high level is used

for this particular project. The methodology of using Aluminium Formwork takes in to

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consideration the important parameters namely the number of housing units, the time that

is available and works out the components of input as form work

This system enables speedy construction like walls, slabs, chajjas,

lofts, etc. in a given portion at one go. Erection and stripping of form work is rapid and

the concreted portion is immediately available for other trades to start their work. Since

all the walls are of concrete, time lost in brick masonry work, which is necessarily slow,

is also saved. These forms are rigid and give excellent surface finish and dimensional

accuracy, eliminating the need for plaster. Openings of accurate dimensions are left in the

walls, which simplifies and expedites fixing of doors and windows. Cutouts of the

required shape and size are left at predetermined locations for electrical, plumbing and

sanitary services. This eliminates subsequent breaking for cutouts and patchwork and the

possibility of leakages through such patchwork. Therefore this system is eminently

suitable for mass housing.

● Comparison :

Comparison Between Aluform and Conventional Form System

Sr. No.

Characteristics AluForm System ConventionalFormwork System

1. Speed of construction Four days cycle per floor

Ten days cycle per floor

2. Quality of surface finish Excellent; plastering is not required

Bad

3. Pre-planning of form work system

Required Not required

4. Type of construction Cast-in-situ Cellular construction

Simple RCC framed construction

5. Wastage of form work material

Very less In great amount

6. Accuracy in construction Accurate construction Less than Aluform

7. Coordination between different agencies

Essential Not necessarily required

8. Resistance to earthquake Good resistance Less than Aluform9. Reusage value 250-300 50

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Conclusion :-

After doing a lot of study and overall comparison with

conventional system, Naiknavare & Associates have decided to use this system of form

work for this particular project. And the System is proved to be advantageous and

economical than conventional system for this project.

CONCLUSION

Formwork contributes a major part of cost in most of the building

construction activities. The selection and effective use of form work also dominate the

success of a project in terms of speed, quality and dimensional accuracy of the final

product. An appropriate form work system is always cost and labour effective,

convenient to handle, fulfilling complicated physical or engineering requirements, and

most important of all, it should be safe to use.

Requirements of an effective housing system :-

Must be cost effectiveMust be capable of a fast rate of constructionMust be adoptable to any structural design or architectural layoutMust produce high quality, durable and low maintenance structures

But the Housing Scenario in India is constantly changing. So the new

construction system is required to fulfill all above requirements and to tackle the present

situation.

REFERENCES

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Hemant Naiknavare; “ Aluminium Formwork System ”, paper presentation on ‘ Fast

Track Construction Technology ’, held at Hotel Pride Executive, Pune, in CEMCON

2004, pp. 19-23.

Khandekar V. G.; “ Cast-in-situ Cellular Construction – A New Approach To Mass

Housing Programme In Urban Areas ”, Mumbai, 2001, pp. 93-111.

Kulkarni D. V.; “ Build One Floor Per Day ”, ‘ Construction World ’, special report,

September 1999, pp. 69-74.

Kulkarni D. V.; “ Use of Pre-engineered Aluminium Formwork For Mass Housing ”, ‘

The Indian Concrete Journal ’, Cement House, 121, Maharshi Karve Road, Mumbai 400

020, March 2001, pp. 208-213.

MASCON Handbook For Aluminium Formwork.

Nirmitee 2004; “ Aluminium Formwork System ”, paper presentation contest held at M.

I. T., Pune ( January 2004 ).

www.cityu.edu.hk

www.cse.polyu.edu.hk

www.globalite.com

www.mivan.com

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http://www.mivan.com/

http://www.globalite.com/

http://www.cse.polyu.edu.hk/

http://www.cityu.edu.hk/

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