The purpose of this study is to investigate the effect of desert sand as a replacement on the tensile and compressive strength of concrete. To this end, a total of 180 cubic specimens (15×15×15 cm) and 90cylindricalspecimens (15×30 cm) were made with three concrete classes of C20, C25, and C30. Control samples (samples without desert sand) and samples containing 5%, 10%, 15%, and 25% sand were also produced. They were processed in mineral-free water at 7, 14, 21, and 28 days. They were then subjected to pressure and tension tests by a 200-ton digital concrete breaker jack. For the water absorption test, 15 cylindrical samples (7.5×15 cm) were made for C25 and 0%, 5%, 10%, 15%, and 20% desert sand. They were then tested after 28 days. The results showed that the compressive strength at the age of 28 days gradually increased by adding the sand. It reached the highest for C20 containing 10% sand. However, it reached the highest foe C25 and C30 containing 5% sand. Adding sand over 20% leads to decreasing compressive strength. The tensile strength of C25 and C30 concrete containing 5% sand and C20 concrete containing 10% sand was the highest compared to the control sample. Adding sand up to 10% leads to decreased water absorption, and then it increases after adding sand. پرونده مقاله