Concrete properties with recycled coarse aggregate and rice husk ash: factorial design study

Methods of design of experiment have been implemented for the evaluation of the impact of the inclusion of recycled coarse aggregates (RCA) and rice husk ash (RHA) on strength and other chosen parameters of concrete. A specific general factorial design method, two-way analysis of variance (Anova), has been used for the current exploration considering two key factors – that is, percentage of RCA (0% and 100%) and percentage of RHA (0%, 5%, 10%, 15%, 20%, 25%, 30% and 35%). This approach has been used to assess the effect of these materials on various concrete properties, including 3, 7, 28 and 90 days compressive strength, modulus of elasticity, water absorption, volume of voids and density. The outcomes of the analysis have been presented in the form of Anova table, individual, main effect, contour and interaction plots. The results of the analysis show that the levels of RCA and RHA had a significant effect on the properties of concrete.