Optimizing Fly-Ash Cement Ratios For Load-Bearing Cement Blocks: Technical Considerations and Recommendations

Abstract

One of the global tendencies regarding the possibility of using fly ash as a cement mortar ingredient, to save the amount of cement being consumed, is to conserve the environment and maintain the ecosystem. This research sought to establish the optimum quantity of fly ash that should be included in cement mortar so as to obtain the necessary strength. The blocks were tested on their compressive strength, water absorption, and density in different treatments at specific intervals of 07 days to 28 days. There was a very high correlation between the fly ash content of cement mortar blocks and the compressive strength, water absorption, and density using statistical analysis. According to the test results, the compressive strength and density of the blocks produced decreased progressively as the amount of fly ash was increased, whereas the water absorbed in the blocks was higher. The application of fly ash up to 40 percent increases water absorption to within an acceptable limit of 15 percent and reduces compressive strength below the limit of 200 kg/cm2 of load-bearing cement blocks. The mixing of fly-ash concrete block should not exceed 40 percent fly ash in cement mortar.