Devdas Menon

Use of rapid techniques for timely delivery of construction projects by adopting fast methodologies and alternate building materials is necessary in India, given the tremendous housing shortage. Further, the construction has to be affordable and also sustainable. The construction technique proposed in this paper, by making use of Glass Fibre Reinforced Gypsum (GFRG) panels (with reinforced concrete infilled cavities) to build homes, promises such a solution for rapid affordable mass housing in India. GFRG building system is a rapid building technology composed of prefabricated wall panel load bearing system. GFRG is also an eco-friendly building material which can be manufactured out of either natural or industrial gypsum. In India, these panels have been manufactured from the fertilizer by-product waste. As an outcome of the research done at IIT Madras on the feasibility of using these panels for affordable mass housing in India, a two-storeyed GFRG building of 184 square meter area was built at IIT Madras campus, as a demonstration of the suitability of this technology. This is described in this paper.

Glass fiber reinforced gypsum (GFRG) panels are used as walls and slabs with reinforced concrete (RC) infilled in their cavities. The behavior prediction of RC infilled GFRG walls under lateral load requires proper modelling techniques. In the present study, a simplified analytical model is proposed for the estimation of lateral load-displacement behavior of GFRG walls with RC infill. The model uses the moment-curvature relations developed using the proposed algorithm assuming linear strain variation along the width of the wall. The effect of interfacial slip is also accounted for in the present formulation by applying a correction factor to initial stiffness. The predicted values showed reasonable match when compared with experimental results.

Glass Fibre Reinforced Gypsum (GFRG) panel is a light-weight load-bearing hollow building panel, used as structural elements (walls, slabs etc.) with Reinforced Concrete (RC) filled inside the cavities. In GFRG construction, usually all the load bearing walls start from the foundation itself. But the ever-growing issue of land scarcity compels the housing sector to have the provision of parking space at the ground storey of the building. This will require the GFRG walls to be supported on an RC frame structure with columns, beams and slabs. The columns of such a structure can potentially cause a brittle mode of failure under the action of seismic forces, owing to the development of plastic hinges resulting in storey mechanism. The behaviour of such structures under combined gravity and lateral loads (monotonic and cyclic) was evaluated in the present study through quasi-static testing of two full scale specimens. The failure of the specimen under lateral loading was characterised by the failure of wall panel, with extensive crack formation before the yielding of frame members. The test results demonstrated the feasibility of designing GFRG wall on RC frame system without leading to brittle collapse mechanisms.

The tremendous housing need of India is causing the depletion of virgin building materials. In an era of scarce resources, sustainable solutions are always preferable. Glass Fibre Reinforced Gypsum (GFRG) technology is one such solution where all the structural members are constructed using hollow panels infilled with reinforced concrete (RC), as per structural design. This paper discusses the sustainability of construction using GFRG panels in terms of embodied energy and indoor thermal comfort. The case study building at IIT Madras campus was found to have lesser embodied energy compared to conventional buildings. The result is significant considering the fact that the building sector consumes 40% of the total energy in world. Also, the inside temperature was found to be lesser by 2 °C which will help in reducing the air conditioning requirement of the building and thereby the operational energy.