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
SCOE.
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 multi-storeyed buildings and enables enables the walls and slab to be poured in the same operation. operation. This increases efficiency, and also produces an extra-ordinaril extra-ordinarily y 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 prefabricated with the certain certain knowledge 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 in both low-rise & high-rise buildings. It 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 work of other other conne connect cted ed const construc ructi tion on trade tradess such such as stee steell reinf reinfor orce ceme ment, nt, concr concret etee placement placement and mechanical mechanical & electrical electrical inserts. 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
SCOE.
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 third of their their steel steel equivale equivalent nt opens opens the way to greatly greatly increase increased d site site acceptan acceptance ce and productivity. productivity. Nearly Nearly 99 percent of the equipment equipment is made of aluminium, aluminium, the other one percent is steel. steel. The use of aluminium aluminium allows larger components 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
SCOE.
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 for bricks, bricks, blocks or plastering. 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 that no plastering is required. required. The tendency of plastering to break away away is well well known.
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Aluminium Formwork
SCOE.
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 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
SCOE.
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 -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 impo import rted ed form form work work This This is the the reas reason on to prom promot otee the the desi design gn,, deve develo lopm pmen entt and 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 than conventional conventional system because because of great speed, good quality 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
SCOE.
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 against 14 to 20-day 20-day cycle cycle in the conventi conventional onal method, method, comple completed ted RCC structure structure is available for subsequent finishing trades much faster, resulting in a saving of 10 to 15 days per floor floor in the overall overall completi completion on period. 3. Quality of Work Construction Construction carried out by this system has exceptio exceptionall nally y good quality quality with with accurate accurate dime dimensi nsions ons for all all openi opening ngss to rece receive ive windows and doors, right angles at meeting points of wall to wall, wall to floor, wall to ceiling ceiling,, etc. etc. Concret Concretee surface surface finishe finishess are good good to rece receiv ivee pain paintt dire direct ctly ly with withou outt plaster. plaster. Monolithic Monolithic construction construction of load bearing walls and
Su erio eriorr
uali ua litt of Cons Constr truc ucti tion on
slabs in
concrete concrete
produces produces structurally structurally superior superior quality quality with very few construction joints compared to
the conventional column and beam slabs construction combined with filler brick work or block work work subsequently subsequently covered covered by plaster plaster..
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Aluminium Formwork
SCOE.
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 manua manuall lly, y, towe towerr crane craness are are not requi require red d and and can can conce concentr ntrate ate on the the other other handl handling ing 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 brickwork or openings openings can can be entertained entertained ). 2. Due to the tremendous speed of construction, working capital finance needs to be planned in in advance. 3. Superior quality paint is required.
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Aluminium Formwork
SCOE.
Application
Nagari Nivara Nivara Parishad Parishad Housing Housing Project, Project, Mumbai. Mumbai. No. of Housing Housing Units Units :- 3600 Total Built-up Floor Area :- 144750 sq. m. Total Concrete Forming Area :- 698700 sq. m.
Formwork Equipment Used :Horizontal – 1180 sq. 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 Buildings :- 15 ( stilt stilt + 11 storeyed 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 identif identified ied,, to be suitabl suitablee for Indian Indian conditio condition n for mass housing housing constru constructi ction on where where quality and speed can be maintained at a reasonably high level is used for this particular project. The methodology methodology of using Aluminium Aluminium Formwork Formwork takes in to consideration consideration the 11
Aluminium Formwork
SCOE.
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 concreted portion is immediately immediately available 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 eliminate eliminatess subseq subsequent uent breaking breaking for cutouts cutouts and patchwor patchwork k and the possibil possibility ity 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 particular project. project. And the System is proved to be advantageous advantageous and economical 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 appropriate form work system is always cost and labour effective, 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; Naiknavare; “ Aluminium Aluminium Formwork Formwork System ”, paper presentation presentation on Track Construction Construction Technology Technology ’, held at Hotel Pride Executive, Executive, Pune,
‘ Fast
in CEMCON CEMCON
2004, pp. 19-23. Khandeka Khandekarr V. G.; “ Cast-in Cast-in-si -situ tu Cellula Cellularr Constr Construct uction ion – A New Approach Approach To Mass 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 Nirmitee 2004; “ Aluminium Aluminium Formwork Formwork System ”, paper presentation 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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