Application of Composites in Infrastructure – Part I and II

Composites have been in application for the past 3 – 4 decades, but only in the last decade that engineers have been given any serious consideration for its application in civil infrastructure: such as bridges, roads, earthquake retrofitting of buildings etc. In this paper the growth of application of composites in civil infrastructures and some of its implications are discussed. This paper is divided into 3 parts: Part-I) Materials aspect fundamentals of composite materials, the matrix and fibers used, Part-II) Composites industry viewpoint: outlook of an engineer of the Australian branch of a worldwide composites manufacturing company towards infrastructure applications, and Part-III) a Structural engineer’s observation on the increased application of composites in civil infrastructure (this part is in the next paper). Part I: Fundamentals of Composites as new engineering / structural materials The construction materials that men used for the buildings and bridges have always identified human civilization at any given time. In the beginning it was wood, then came stone, followed by bricks and mortars. Lately we saw the use of cast iron and steel, followed by reinforced concrete and prestressed concrete. The civilization moved from the Stone Age, to the age of advanced steel and concrete. However, since 1970 a new age has started – the age of composite construction materials. Composite materials have already been extensively used in the aircraft industry, space industry, and auto and transportation industry. In the beginning the military usage were predominant. Various aircraft, helicopters and rockets were built using composites and high strength adhesives. Initially certain parts were made of composites. Gradually entire structural frames and the bodies were built by composite material. It was found to be an easily repairable material. At present some of the engine parts are made of composite materials. Gradually commercial airlines started to use the same materials (CFRP, GFRP and AFRP). At present, large number of automobile manufacturers, throughout the world, is using composite material bodies. Large trucks, shipping containers, ships and even moving engine parts are now made of composite materials 1.1 Composite materials are: * structured combinations of continuous and discrete phases in which * the stronger and stiffer discrete phase (reinforcement) is held * in the weaker and softer continuous phase (the matrix) by interfacial bonding.