IRANIAN JOURNAL OF SCIENCE AND TECHNOLOGY-TRANSACTIONS OF CIVIL ENGINEERING, vol.47, no.4, pp.2173-2187, 2023 (SCI-Expanded)
In this study, environmentally friendly and economic geopolymer concrete (GPC) was produced as an alternative to cement-based concrete. It is possible to substitute basalt and marble dust in specific proportions instead of fly ash as a binder material in GPC production. The GPC samples were obtained by replacing 25%, 50%, and 75% fly ash with waste basalt and marble powder. Moreover, some of them were only produced from fly ash, basalt, and marble powder. As a result of the study, the average strength of the samples made with only fly ash was 30 MPa, while the average strength of the samples with 25% basalt and marble powder was 31 MPa. While adding 25% basalt and marble powder provides the highest value in compressive strength, it is seen that the basalt powder provides 15% better compressive strength with the addition of 50%. In GPCs made with only marble and basalt powder, basalt powder has a 26% superiority. In addition, there are changes in the ductility and energy absorption capacity of GPC due to the increase in both basalt and marble waste. While the ductility was 2.85 in the sample obtained with a mixture of 50% basalt and marble powder, it was 1 in the sample with 25% basalt. Samples with high compressive strength generally resulted in brittle fractures. Basalt and marble wastes promise an excellent future to improve the fragile structure, which is the negative aspect of GPC. In addition, values such as slump, elasticity, and unit strain results show that the mechanical properties of the GPC with 25% waste basalt and marble powder additives instead of fly ash are at the desired level or even better.