Partial Replacement Of Natural River Sand With Crushed Rock Sand In Concrete Production

Abstract

The use of crushed rock sand as a partial replacement of river sand in concrete production was investigated. Water cement ratio varied between 0.55 and 0.59 for 0 % to 100 % natural sand replacement. The slump ranged between 49 and 60 mm for 0 % to 100 % natural sand replacement. The average compressive strength of the control concrete (C20) was 22.5 N/mm 2 . The effective natural sand (RS) replacement ranged between 0 and 60 % with the best results achieved at 20 % replacement. The peak compressive strength and indirect tensile strength values of 23.2 N/mm 2 and 1.42 N/mm 2 respectively were obtained. Modulus of elasticity of concrete increased from 22 KN /mm 2 to 23 KN/mm 2 with 20 % replacement of natural sand. Also, the indirect tensile strength increased from 1.28 N/mm 2 to 1.42 N/mm 2 with 20 % river sand replacement. The beam deflection ranged between 0.25 mm and 0.4 mm with the lowest deflection recorde d at 20 % CRS and highest deflection of 0.4 mm with the control mix (0 % CRS). The whole range of natural sand replacement (0 to 100 %) improved the beam deflection. The 20 % CRS content recorded the highest flexural strength of 686.7 N/mm 2 beyond which th e strength decreased to 80 % CRS after which there was a constant value in strength up to 100 % CRS