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 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 heavy investm investment ent in the plant plant & machine machinery ry and subseq subsequent uent dependence dependence on import imported ed 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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Aluminium Formwork

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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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Aluminium Formwork

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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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Aluminium Formwork

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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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Aluminium Formwork

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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 Total Floors in One Building Area of One Floor Total Formwork Equipment

15 11 4500 Sq. ft. i.e. 420 Sq. m. 1570 m2

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Aluminium Formwork

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Table No. 1 Costing For Locally Manufactured Formwork 

Sr.  No. 1.

Item

Figure

Cost of Aluminium Formwork per Sq. m.

Rs. 10,000

2.

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.

Shuttering Work 

Rs. 17 / Sq. ft.

Rs. 12 / Sq. ft.

2.

Reinforcement Work 

Rs. 10 / Sq. ft.

Rs. 7 / Sq. ft.

3.

Concreting

Rs. 4.50 / Sq. ft.

Rs. 2.50 / Sq. ft.

4.

Masonry and Plastering Work  Total

****

Rs. 28 / Sq. ft.

Rs. 31.50 / Sq. ft.

Rs. 49.50 / Sq. ft.

Table No. 3 Overall Comparison of Imported Formwork 

Sr. Description  No.

Aluform

Conventional System

1.

Cost of Shuttering Material

Rs. 57.00 / Sq. ft.

Rs. 20.00 / Sq. ft.

2.

Labour Cost

Rs. 31.50 / Sq. ft.

Rs. 49.50 / Sq. ft.

Total

Rs. 88.50 / Sq. ft.

Rs. 69.50 / Sq. ft.

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Aluminium Formwork

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Table No. 4 Overall Comparison of Locally Manufactured Formwork 

Sr. Description  No.

Aluform

Conventional System

1.

Cost of Shuttering Material

Rs. 27.50 / Sq. ft.

Rs. 20.00 / Sq. ft.

2.

Labour Cost

Rs. 31.50 / Sq. ft.

Rs. 49.50 / Sq. ft.

Total

Rs. 59.00 / Sq. ft.

Rs. 69.50 / Sq. ft.

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

Handling of panel by a single worker 

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Aluminium Formwork

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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

Su erior

ualit of Construction

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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Aluminium Formwork

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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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Aluminium Formwork

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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 :Builder :-

Naiknavare & Associates 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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Aluminium Formwork

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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.

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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 consideration the 11

Aluminium Formwork

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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. 1. 2. 3.

Characteristics Speed of construction

Four days cycle per   floor  Quality of surface finish Excellent; plastering is not required Pre-planning of form work  Required system

4.

Type of construction

5.

Wastage of form work   material Accuracy in construction

6. 7. 8. 9.

AluForm System

Coordination between different agencies Resistance to earthquake Reusage value

Conventional Formwork System Ten days cycle per  floor  Bad Not required

Cast-in-situ Cellular   construction Very less

Simple RCC framed construction In great amount

Accurate construction

Less than Aluform

Essential

Not necessarily required Less than Aluform 50

Good resistance 250-300

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Aluminium Formwork

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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 effective Must be capable of a fast rate of construction Must be adoptable to any structural design or architectural layout Must 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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Aluminium Formwork

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Hemant Naiknavare; “ Aluminium Formwork System ”, paper presentation on Track Construction Technology ’, held at Hotel Pride Executive, Pune,

‘ Fast

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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