Flexural behaviour of cement added geopolymer concrete

Abstract

This work aims to improve the flexural behaviour of Geopolymer Concrete (GPC). GPC is an ecofriendly concrete in which Ordinary Portland Cement (OPC) is completely replaced by pozzolanic materials i.e. Fly Ash or GGBS or Rice Husk Ash and activated alkaline solutions like NaOH or KaOH and Na2SiO3 to act as a binder in the concrete mix. GPC having its own advantages over the OPC concrete, like faster setting time, early age strength and also GPC is a good alternative material for OPC to control the emission of green house gases. But GPC required heat curing. This problem was overcome with partial replacement of fly ash by lime or GGBS or cement. In this study, 2 to 6% of fly ash was replaced by cement or GGBS in GPC. Among the above combination, partial replacement of Fly Ash by cement in GPC shows better performance in mechanical properties of GPC. A comparative study of flexural behaviour of beam with RCC, Geopolymer Concrete beam with 6% replacement of GGBS in fly ash (GGPC) and Geopolymer Concrete beam with 6% replacement of cement in fly ash (CGPC) has been done. The test results revealed that CGPC beams shows better results in compressive strength as well as in flexure and setting time is also reducing considerably when compare with GGPC. CGPC beam shows that less amount of deflection and greater moment of resistance than that of GGPC beam.