Effects of foundry sand as a fine aggregate in concrete production

This paper presents the results of experiments carried out to evaluate the utilization of foundry sand (FS) as a substitute material for fine aggregate in concrete production. The physical and chemical characteristics of the FS were also addressed. FS obtained from the aluminium casting industry was used as a substitute for fine aggregate in five different substitution rates (10%, 20%, 30%, 40% and 50%). Several tests, including density, slump cone, split tensile strength, flexural strength; ultrasonic pulse velocity (UPV) and compressive strength tests were performed to understand the effects of FS on the behavior of concrete. The grain size distribution analysis of FS revealed that 8% of FS were less than 75 μm, and the water absorption of FS was about 1.13%. The test results revealed that the strength properties of the concrete mixtures containing FS up to 20% was relatively close to the strength value of the CM, and the average decrease in strength was only 2.1%. The decrease in the strength is attributed to the fineness of the FS and the presence of dust, clay and wood flour in the FS. From the test results obtained it was concluded that a substitution rate of up to 20% can be effectively used in good concrete production without affecting the concrete standards, and a substitution rate beyond 20% is not beneficial.