Concrete
Concrete is a wonder material that has transformed the way we build roads, houses, dams, canals bridges and tunnels. Historically it is only a recent material although it is ubiquitous today because it has opened up immense possibilities of new design of structures and expression of artistic values in ways never possible before. Concrete was developed about 120 years back and it is a mixture of binding material, coarse aggregate, fine aggregate and water which makes the binding possible. Typically Coarse aggregate used is gravel, fine aggregate is sand and binding material is cement. The major advantages of using concrete is that it can be fabricated practically anywhere and can be molded and cast into a variety of shapes and geometries. Concrete is very good in compression and it can be prepared at desired strengths by changing the proportion of its contents. There have been many innovations in concrete since its development. There are wide range of chemicals that are commercially available which bring certain desired qualities to the concrete when added in right quantities which are called admixtures. For example, free flow of concrete is desired during construction for which admixtures are available and technically such concrete is called ‘Self Compacting Concrete’.