Abstract:
Concrete is a major component of modern building practices. Researchers have been looking into viable alternatives to cement and natural aggregate because of the rapid depletion of natural resources, the enormous amounts of energy consumption, and the environmental degradation. Concrete's ability to resist fire is another major factor which requires attention. Slag based lightweight geopolymer concrete, which makes use of industrial wastes including Fly Ash (FA), Ground Granulated Blast Furnace Slag (GGBFS) and slag aggregate, has emerged as a possible alternative to address these challenges, thanks to their promising eco-friendliness and fire resistance. The fire resistance and mechanical properties at high temperatures of lightweight geopolymer concrete are compared with those of control samples in this investigation. FA and GGBFS are used to make an alkali-activated light weight geopolymer concrete matrix with various replacement ratios (F60G40, F50G50, and F40G60, respectively). The samples of geopolymer concrete were left to cure in the air for 28 days. At room temperature, 200, 500, and 800 °C, the material's mechanical properties were evaluated. While the control sample only managed 30 MPa and 4.4 MPa in compressive and flexural strength, respectively, at room temperature, the F60G40 mixture obtained 37 MPa and 5.5 MPa. All specimens lost strength with increasing temperature, although the F60G40 mixture lost less strength than the controls. The compressive strength of the F60G40 mixture remained at 13.1 MPa and the flexural strength at 2 MPa even after being heated to 800 °C, while those of the control sample were 11.8 MPa and 1 MPa, respectively. The stress-strain responses, elastic modulus retention, and energy absorption of geopolymer concrete were also significantly improved.
