Affordable Rapid Mass Housing Using GFRG Panels

Guided By:Prashant Kumar Nayak

Presented By:Suman Pati

ABSTRACT

• There is a huge growing requirement of building materials in India due to the existing housing shortage of 24.7 million units{ 2007} mainly for the low income groups in urban India.

• Estimated urban housing shortage in 2012 is 26.53 million, while the housing shortage of rural India in 2012 is 42 million units. Thus total estimated housing shortage for Urban & rural India in 2012 is 68.53 million units.

• To meet this challenge, India requires innovative, energy efficient building materials for strong and durable housing in fast track method of construction at affordable cost. It is also important that housing and buildings are disaster resistant to protect the lives and properties of people.

INTRODUCTION TO GFRGThe building industry accounts for 40% of CO2 emissions. GFRG panel is an energyefficient green building material with huge potential for use as load bearing and non loadbearing wall panels. GFRG panel is a large load bearing panel with modular cavitiessuitable for both external, internal walls as well as floor slab or roof slab in combinationwith RCC as a composite material. Rapidwall buildings are resistant to earthquakes, fireand cyclones. Rapidwall panels based on construction manual prepared by IIT Madras tosuit Indian situation. FACT & RCF, two fertilizer giants under public sector are togethersetting up Rapidwall and plaster products manufacturing plant at Ambalamugal usingRapidwall technologies of Australia called FACT RCF Building products Ltd. (FRBL). FACThas about 7 million tons of industrial by product gypsum. Glass fiber reinforced gypsum is made up of glass fiber and gypsum wastage from fertilizer industry.

PHYSICAL AND MATERIAL PROPERTIES

Rapidwall panel is world’s largest load bearing lightweight panels. The panels aremanufactured with size 12 m length, 3m height and 124 mm thickness. Each panelhas 48 modular cavities of 230 mm x 94 mm x 3m dimension. The density is1.14g/cm3 , being only 10-12% of the weight of comparable concrete /brickmasonry. The physical and material properties of panels are as follows:

Weight 44 Kg/ sqm

Axial load capacity 160 kN/m{ 16 tons/ m}

Compressive strength 73.2 Kg/cm2

Flexural strength 21.25 kg/cm2

Tensile Strength 35 KN/ m

Fire resistance 4 hr rating withstood 700-10000 C

Elastic Modulus 3000-6000Mpa

Water absorption < 5%

MANUFACTURING OF GFRG PANEL

TRANSPORTATION AND LIFTINGPanels are vertically loaded at the factory on stillages for transport to the constructionsites on trucks. Each stillage holds 5 or 8 pre-cut panels. The stillages are placed at theconstruction site close to the foundation for erection using vehicle mounted crane orother type of crane with required length for construction of low, medium and high risebuildings. Special lifting jaws suitable to lift the panel ,are used by inserting into thecavities and pierced into webs, so that lifting/handling of panels will be safe.

JOINTS AND CAVITIESWall to wall ‘L’, ‘T’, ‘+’ angle joints and horizontal wall joints are made bycutting of inner or outer flanges or web appropriately and infill of concretewith vertical reinforcement.

CONSTRUCTION PROCEDUREFOUNDATION: For Rapidwall Housing a conventional foundation like spread

footing, RCC column footing, raft or pile foundation is used as per the soil condition and load factors. All around the building RCC plinth beam is provided. Conventional water proofing materials are used in the foundation

RAPAID WALL: Rapidwall enables fast track method of construction. Conventional building construction involves various time consuming processes, like i) masonry wall construction ii) cement plastering requiring curing, iii) casting of RCC slabs requiring centering and scaffolding and curing iv) removal of centering and scaffolding and v) plastering of ceilings and so on.Construction time is minimized to 15-20% by the rapid wall method. Instead of brick by brick construction, Rapidwall enables wall by wall construction. Rapidwall also does not require cement plastering as both surfaces are smooth and even and ready for application of special primer and finishing coat of paint.OPENINGS: Door/window/ventilator, openings will be cut and reinforced concrete is provided there.

LINTEL: Embedded RCC lintels are to be provided wherever required bycutting open external flange. Reinforcement for lintels and RCC sunshadescan be provided with required shuttering and support.

CONCRETE INFILL : After inserting vertical reinforcement rods as per thestructural design and clamps for wall corners are in place to keep the wallpanels in perfect position, concrete of 12mm size aggregate will be pouredfrom top into the cavities. There is no need to use vibrator becausegravitational pressure acts to self compact the concrete inside the water tightcavities. Generally every third cavity should be concreted.

TIE BEAM: An embedded RCC tie beam to floor/roof slab is to be provided ateach floor/roof slab level, as an essential requirement of national buildingcode against earth quakes. For this, web portion to required beam depth at

topis to be cut and removed for placing horizontal reinforcement with stirrups andconcreted.

ROOF SLAB:Instead of a solid concrete floor slab, which is typically 100 to 150mm thick, the GFRG

panels are used. They are placed horizontally over the walls in different roofs. The roofs typically spanning along the shorter direction. Concrete tie beams connect the panels to the walls at all junctions. Every third cavity in the horizontal GFRG panel is cut open from the top and reinforced cage is inserted to serve as a concealed beam. Further a steel welded mesh is placed on top of the entire floor slab and subsequently embedded in screed of concrete 50mm thick. The advantage with the system over conventional concrete slabs is the there is no need of shuttering and the finish at bottom is excellent. It also not required any plastering.

Conduits for electrical work are kept in place before concreting the slab.

STAIR CASE: The stair case work is taken up using GFRG panels as the landing slab with reinforced concrete bars in all the cavities.

FINISHING WORK: Once concreting of ground floor roof slab is completed, on the 4th day, wooden planks with support props in ground floor can be removed. Finishing of internal wall corners and ceiling corners etc can be done using wall putty or special plaster by experienced plasterers. Simultaneously, electrical work, water supply and sanitary work, floor tiling, mosaic or marble works, staircase work etc can also be carried out.Every upper floor can be finished in the same way.

COMPERISON Comparative study of Rapidwall building and conventional building (For 2storey 1500 sft):

Materials/ items Rapidwall Building Conventional Building Saving in %

Cement 16 tons 32.55 tons 50.8

Steel 1800 kg 2779 kg 35.2

Sand 20cum 83.37cum 76

Granite 38cum 52.46cum 27.56

Bricks - 57200

GFRG panel 500sqm -

Water 50000ltr 200000ltr 75

Labour 389 mandays 1200 mandays 67.59

Construction time 21 days 120 days 82Wt. of superstructure 170 tons 490 tons 65

Construction cost Rs 13.25 lakhs Rs 18.27 lakhs 61.5

CONCLUSIONRapidwall Panel provides a new method of building construction in fast track, fullyutilising the benefits of prefabricated, light weight large panels with modular cavitiesand by the use of concrete and steel reinforcement. By this process, man power, costand time of construction is reduced. The use of scarce natural resources like riversand, water and agricultural land is significantly reduced. Rapidwall buildings therebyreduce burdening of the environment and help to reduce global warming. Rapidwalluse also protect the lives and properties of people as these buildings will be resistantto natural disasters like earthquakes, cyclone, fire etc. This will also contribute toachieve the goal of much needed social inclusive development due to its variousbenefits and advantages with affordability for low income segments also. Fast deliveryof mass housing is very critical for reducing huge urban housing shortage in India.Rapidwall panels will help to achieve the above multiple goals.

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