IIT Madras unveils 'GFRG Demonstration Building'

Advantages over conventional buildings:

-- High speed of construction: GFRG demo building with four flats in two storeys (total 1981 sq. ft.) built within a month!

-- Less built-up area for the same carpet area: wall panels are only 124mm thick.

-- Less embodied energy and carbon footprint: significant reduction in use of cement, sand, steel and water; recycling of industrial waste gypsum.

-- Lower cost of structure: savings in materials; no plastering.

-- Lower building weight (panels weigh only 43 kg/m2), contributing to savings in foundation and reduction in design for earthquake forces, particularly in multi-storeyed construction.

-- Buildings up to 8-10 storeys can be designed using this load-bearing system, without the need for beams and columns.

-- Excellent finishes of prefabricated GFRG panels – used for all the walls, floors and staircases, with minimal embedded concrete: no need for additional plastering.

Researchers in the Civil Engineering Department of the Indian Institute of Technology Madras (IIT M) have developed a method of design and construction to make use of Glass Fibre Reinforced Gypsum (GFRG) panels to build rapid, cost-effective mass housing. To showcase this technology, a 'model housing apartment' comprising four flats in a two-storeyed building, has been constructed inside the IIT-M campus. The ‘GFRG demo building', constructed in just a month, was inaugurated today by Sri TKA Nair, Advisor to Honourable Prime Minister of India, in the presence of Prof. Bhaskar Ramamurthi, Director, IIT Madras.

Since 2003, the IITM research team had conducted extensive studies on the use of these panels as structural members for all components of the building, including earthquake resistant design. These panels, originally developed by RBS Australia, were intended as wall panels ('Rapidwall') suitable for rapid erection of walls in buildings to carry gravity loads. The panels are made of calcined gypsum plaster, combined with special additives and glass fibres, to produce GFRG panels – 12m long, 3m high and 124mm thick (with hollow cavities). The IITM research group extended the application of this product for the entire building system – including floors, roofs, and staircases, thus significantly reducing the consumption of Reinforced Cement Concrete (RCC). The team also collaborated in the indigenous development of an excellent water-proofing material, which is essential for prolonged durability of the GFRG panels, especially in the case of roofs and toilets.

The GFRG panels for the 'demo building' at IIT Madras have come from the plant of FACT-RCF Building Products Ltd, Kochi, using reprocessed gypsum from FACT. The building has four units, making up a total built-up area of 1981 sq. ft. -two flats with a carpet area of 269 sq. ft. each, intended for the economically weaker section (EWS), and another two, with a carpet area of 497 sq. ft. each, intended for the low-income group (LIG). The plans can be replicated horizontally (in plan) and vertically (in elevation) in mass housing projects. This demonstration building will also be used by another research group at IITM Madras working on decentralized solar photovoltaic systems with Direct Current (DC) appliances, to demonstrate savings in electrical energy consumption.

Prof. Bhaskar Ramamurthi, Director, IIT Madras said, "The GFRG building, which is fit for occupation, showcases the efficacy of the rapid affordable construction technology developed at IIT Madras, and is replicable for mass housing, vertically and horizontally. The use of prefabricated light-weight GFRG panels not only implies faster overall construction time but also a safer working environment. The cost of the construction, with all amenities, has been reduced to about Rs.1, 250 per square foot."

The panels are prefabricated and cut to desired sizes based on room dimensions with openings for doors and windows, thus making rapid construction possible. A panel has two skins of 15 mm thickness that are interconnected at regular intervals (250 mm) with 20 mm thick ribs. The cavities formed by these interconnections can be used for several purposes — filling with concrete, and laying electrical conduits and plumbing pipes.

Explaining the building concept, Prof. Devdas Menon and Prof. A. Meher Prasad of Civil Engineering Department, IIT, Madras said, "Filling the cavities with concrete increases the vertical load-carrying capacity almost tenfold, and inserting vertical steel bars in these cavities, contributes to their earthquake resistance. In a multi-storeyed building, the number of concrete-filled cavities and steel bars can be reduced at the higher floor levels. When used as floor slabs, reinforced concrete beams can be embedded and hidden in some of the cavities, as per the design. The overall weight of the structure and consumption of concrete comes down significantly. Conventional plastering is eliminated."