Composites as Building Material – Indian Scenario
Indian efforts centre around developing cost effective building materials as well as for catering to the housing needs of urban & rural poor. In this context, certain developments concerning glass fibre reinforced polymer composites, natural fibre composites, industrial waste based composites have assumed importance. The key restricting factors in the application of composites are initial costs due to raw materials and also inefficient conventional moulding processes.
Various key product applications being developed in the building & construction industry are prefabricated, portable & modular buildings, exterior cladding panels, interior decorations, furniture, bridges and architecture mouldings. Various proven composite products being used in the housing sector are bathtubs & basins, drainage channels, manhole covers, pits, farm buildings, doors, door frames & windows, cabinets, housing modular, sheeting roof and flat, structural members, portable toilets, ponds & fountains, water storage tanks etc.
Composites for Structural Applications
Composites have long been used in the construction industry. Applications range from non-structural gratings and claddings to full structural systems for industrial supports, buildings, long span roof structures, tanks, bridge components and complete bridge systems. Their benefits of corrosion resistance and light weight have proven attractive in many low stress applications. Composites present immense opportunities to play increasing role as an alternate material to replace timber, steel, aluminium and concrete in buildings.
Bridges account for a major sector of the construction industry and have attracted strong interest for the utilization of high performance FRP. FRP has been found quite suitable for repair, seismic retrofitting and upgrading of concrete bridges as a way to extend the service life of existing structures. FRP is also being considered as an economic solution for new bridge structures. Design approaches and manufacturing efficiencies developed for road bridge applications will benefit their introduction into a broader range of civil construction fields.Decks for both pedestrian and vehicle bridges across waterways, railways and roadways are now a commercial reality in both North America and Europe, with some pedestrian bridges being built entirely from composites. Because of the superior durability of composite, only cosmetic maintenance requirements are expected for at least 50 years. The composite bridge decks are quite suitable for replacing conventional/old bridge decks having super structure intact. The replacement can be carried out in a short time with minimal disturbance to the traffic.
Among a wide array of composite products, pultruded profiles such as gratings, ladders, cable trays, solid rods & other sections are used in many structural application with Class I flame retardancy. Pultrusion is the most cost-effective method for the production of fibre-reinforced composite structural profiles. It brings high performance composites down to commercial applications such as lightweight corrosion-free structures, electrical non-conductive systems, offshore platforms and many other innovative new products. Pultruded sections are well-established alternative to steel, wood and aluminium in developed countries and are fast catching up in other parts of the world. Structural sections have ready markets in oil exploration rigs, chemical industries etc. The amount of energy required to fabricate FRP composite materials for structural applications with respect to conventional materials such as steel & aluminium is lower and would work for its economic advantage in the end. The pultruded products are already being recognized as commodity in the international market for construction.