The Effect of Fly Ash on the Workability and Mechanical Properties of Concrete Slabs: A Review

Cement production in the world accounts for 5% of the annual anthropogenic global carbon dioxide production. This is mainly due to the vast amount of cement is used in the making of concrete slabs. However, the process of production of cement is not environmentally friendly. There is a need for other substitutes or partial replacement of cement in concrete slabs. Fly ash is one such material. Fly ash is a by-product of coal combustion in thermal power stations. Out of hundreds of millions of metric tons of fly ash are produced worldwide only 20–40% is used for productive purposes. The rest is sent to the landfills to be dumped contributing to the pollution of environment. The use of fly ash as a partial replacement of cement in concrete has economic, environmental and mechanical advantages. There are number of studies on the effect of fly ash on different types of concrete. However, only a limited number of studies showing effect of varying fly ash volume fraction on the workability in concrete paste and strength properties in concrete slabs. Therefore, this paper reviews the effect of partial replacement of cement with fly ash on the workability of concrete and the resultant mechanical properties of the concrete slabs.