The research gap on the feasibility of basalt rock powder(BRP)and superfine sand(SS)in preparation of cement mortar is significant.This study examines probable changes occurred in the modified cement mortar due to incorporation of certain quantity of basalt rock powder and superfine sand in mixture proportion.The cement mortar included Portland cement,artificial sand and water as principal mixture constituents.Then,basalt rock powder and superfine sand were added as partial replacement materials for Portland cement and artificial sand respectively.Therefore,replacement percentages were 10%,15%,20%,25%and 30%when the basalt rock powder replaced Portland cement and in case the artificial sand was replaced by superfine sand,10%,20%,30%,40%and 50%.Then,the strength indexes such as flexural strength,compressive strength,ultrasonic pulse velocity and dynamic elastic modulus were investigated.The results show that the presence of basalt rock powder in mixture proportion increased the flexural and compressive strengths of cement mortar however the cement mortar that contained superfine sand illustrated inadequate mechanical performance as flexural and compressive strengths decreased remarkably.Moreover,when basalt rock powder and superfine sand were included together in mixture proportion,the cement mortar’s mechanical performance declined compared to that of the reference cement mortar.Despite the fact that basalt rock powder and superfine sand weakened the cement mortar’s mechanical properties,it was found that they can be added into the cement mortar as partial replacement of Portland cement and artificial sand in the following ratios:from 10%to 25%when basalt rock powder replaces Portland cement and from 10%to 20%when artificial sand is replaced by superfine sand.
