An experimental investigation on the utilization of crushed sand in improving workability and mechanical resistance of concrete

Sand/fine aggregate in concrete is a filler material that plays a key role on the mechanical properties of concrete. This experimental work focused on improving the mechanical properties of concrete by utilizing crushed sand, a byproduct in the manufacturing process of coarse aggregate, as an artificial sand material. Firstly, the combination of crushed sand and river sand in making concrete was investigated with an amount of river sand ranging from 0 to 100 mass-%. There was a synergy effect on improving the workability and mechanical properties of the concrete using the hybrid sand. The optimal amount of river sand was from 30 to 40 mass-% to generate the best workability and concrete resistance under compression and flexure. Moreover, crushed sand could completely replace river sand, with noticeable improvements in the mechanical properties of the concrete. Secondly, the concrete using mono crushed sand was added from 0 to 20 mass-% very fine crushed sand < 0.14 mm of total sand. The optimal amount of fine crushed sand was from 5 to 10 mass-% to possibly produce a favorable effect on the concrete's workability and resistance under compression, flexure, splitting, and abrasion. The shrinkage strain developed rapidly and significantly within five hours after casting, and the abrasion resistance of the concrete increased as its compressive strength increased.