Effect of sugarcane bagasse ash addition and curing temperature on the mechanical properties and microstructure of fly ash-based geopolymer concrete

Geopolymers are a type of inorganic substance that is created in an alkaline environment using alumina-silica gel. Although extensive research has been conducted on geopolymer concrete's mechanical and durability properties, its practical usage is limited by the constraints of attaining optimal curing conditions and the demand for high-temperature curing. These factors make it challenging to use geopolymer concrete in on-site construction projects. The current study aimed to explore the feasibility of substituting fly ash (FA) with sugarcane bagasse ash (SCBA) in geopolymer concrete (GPC) cured at ambient temperature, as a means of resolving this problem. SCBA was utilized as a partial replacement for FA, ranging from 5 % to 20 %. Various tests, including slump test, compressive strength (C_st) test, tensile strength (S_st) test, and flexure (F_st) tests, were performed. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) analysis were used to study the microstructure. Furthermore, the effect of various curing temperatures was investigated. The results show that substituting SCBA for FA can reduce the necessity of curing at high temperatures. Furthermore, following a 28-day period of curing at ambient temperature, the geopolymer concrete mixtures made with FA-SCBA exhibited compressive strengths ranging from 40 to 56 MPa. These results imply that SCBA could be a suitable substitute for FA in GPC applications, reducing energy usage and environmental effects.