Experimental investigation on the compressive and flexural properties of replaced natural sand with foundry sand in concrete development

The paper identifies the compressive and flexural strength of concrete when foundry sand is used instead of natural sand. The proportion of mix ratios in the experiment was 1:2:4 and water-cement ratio 0.6 concrete cubes. Substitute 0, 20, 40, 60, and 100 percent of natural mass sand by foundry sand in compressive strength test and concrete beam flexural test. Compressive and flexural strength were boosted by the percentage composition of foundry sand. The compressive strength increased to 26.27 N/mm2 (60 percent replacement) after seven days as compared to 24.64 N/mm2 (0 percent replacement). The strength increased at 14 days noted to be 26.22 N/mm2 in 0% replacement to 29.10 in 60 replacement and 31.11 in 28 days. This resulted in compressive strength of 28.00 N/mm2 when foundry sand was used as a substitute of all natural sand. The flexural strength rose to 60 percent replacement level, and then decreased. At 0, 60, and 100 replacements, flexural strength was 2.20 N/mm2, 3.10 N/mm2, and 2.50 N/mm2, respectively. This indicates that the mild foundry sand enhances the tensile and bending strength of concrete with the enhancement of cement matrix-aggregate interfacial bonding. Analysis of sieves revealed that the two materials are within acceptable grading limits though, foundry sand exhibits a smaller particle spread in the pack and therefore is more efficient in packing density and less void at the optimum replacement level, making it a good partial replacement of natural sand in concrete manufacture.