THE EFFECT OF RECYCLED RUBBER AGGREGATES AND DUNE SAND OF EL-OUED REGION ON THE COMPRESSIVE STRENGTH OF CEMENTITIOUS MORTAR: OPTIMIZATION USING TAGUCHI METHOD

This study optimizes the effect of recycled rubber aggregates and dune sand of El-Oued's region by maximizing the compressive strength of cementitious mortar using Taguchi's design experiments. The experiments were designed using an L9 orthogonal array to see the different relationships between the factors targeted in our research, namely: water/cement (W/C) ratio, rubber aggregates (RA) content, and dune sand (SD) content, with the levels of each factor in the mortar mixture. The samples were tested at 28 days in each of the nine trial conditions for two responses: compressive strength and ultrasonic pulse velocity. The results of the analysis of variation (ANOVA) show that RA content is the factor that has the largest effect on the two tests, and the second factor affecting the two tests is the W/C ratio. Then, the analysis shows that the SD content has no significant effect on the mechanical resistance of the mortar for the two tests. And from the mathematical models investigated in this study, we conclude that the factors RA content and W/C ratio have a negative influence on the responses of the compression test and the ultrasonic test together.