The increase in the concrete demand due to the rapid industrialization and urbanization may lead to a shortage of natural resources. Therefore, the use of recycled material in the batching of concrete will be helpful to meet the demands of the time without compromising the quality of concrete production. One such waste material produced in Pakistan is waste marble powder (WMP) that is generated from the marble factories during cutting of the marble stones, which in turn have a damaging effect on the environment. This study is based on the utilization of WMP as a partial substitute of the sand in concrete production and its various effect on the mechanical properties of the concrete. Different types of tests (unit weight, workability, compressive strength, splitting tensile strength, and water penetration) were carried out at 0-80%, of sand replaced with WMP, at increments of 20%. In all mixes, the ratio of water to cement was kept constant and the effects of curing conditions were studied at 14, 28, and 70 days. It was observed that with the incorporation of WMP, the workability and unit weight of concrete decrease proportionally to replacement percentage, whereas mechanical properties of concrete increase up to a certain percentage and then decrease. The maximum improvement in compressive strength was achieved at a 40% replacement, with a slight improvement in the tensile strength at 20% replacement. The water penetration test revealed a decrease in permeability with the increase in WMP percentage. Based on the results, it was recommended to use WMP up to 40% in the concrete mix as a replacement of sand.
