By using the previous equations, the tensile strength can be estimated based on the known compressive strength values. The ratio between tensile strength and compressive strength of concrete as a function of percentage of marble dust content at 7, 28 and 56 days of curing is shown in Fig. 19. From this figure, it can be seen that the ratio between tensile and compressive strength increases with the increase of marble dust content as a partial replacement of cement. This ratio ranges from 7.86% to 12.45%. In case of using marble dust as a partial replacement of sand; this ratio ranges from 7.86% to 10.39%.