After water, concrete is the most widely used substance on earth. If the cement industry were a country, it would be the third largest carbon dioxide emitter in the world with up to 2.8bn tonnes, surpassed only by China and the US, and therefore unfortunately, concrete is not an environmentally friendly material, either to make, or to use, or even to dispose of. To gain the raw materials to make this material, much energy and water must be used, and quarrying for sand and other aggregates causes environmental destruction and pollution. Hence, a large number of researchers have focused on the development of a new concrete materials that would be more suitable with environmental necessity than ordinary Portland concrete.