Replacement of Coarse Aggregate in Geopolymer Concrete by using Demolished Waste

Abstract

The increase in the amount of CO2 which is being released into the atmosphere due to the continuous production of cement in the construction industry is intensifying the problem of global warming which has an adverse effect on the environment. Therefore, the necessity of finding a more sustainable approach other than the existing admixtures used to replace conventional concrete has become highly exigent. That leads to the investigations on geopolymer concrete (GeoPC), which exhibit high strength and similar or better durability when compared to conventional concrete. GeoPC is a relatively new sustainable engineering concrete and it has the advantage of cement replacement with supplementary cementitious materials which are combined with alkali-activated solutions. Geopolymer concrete is also known as green concrete or cementless concrete which is produced by 100% replacement of cement with the waste materials obtained from the various industries. It is an innovative construction material that shall be produced by the chemical action of inorganic molecules such as fly ash, alccofine, and alkaline activators which are sodium hydroxide and sodium silicate. It is the complete replacement of cement in the concrete. It can be used as the best substitute for ordinary Portland cement (OPC). In this project, we are replacing the coarse aggregate used in geopolymer concrete with demolished concrete waste. For checking the efficiency of this concrete we have to do various tests like compressive strength test, split tensile test, flexural strength, slump test, etc. The demolished concrete can be used after crushing, sieving and cleaning.