Reuse of Chemically Bonded Waste Foundry Sand in Structural Concrete

Disposal of industrial waste has become a great burden globally due to its associated high economic expense and environmental pollution. The possibility of re-using Waste Foundry Sand (WFS) as fine aggregate in concrete profits both construction and industrial sectors. The present study aimed at examining the reuse of chemically bonded WFS as fine aggregate in concrete paver blocks. It assessed the physical and chemical properties of chemically bonded WFS and the effect of chemically bonded WFS as partial replacement of natural sand at 0 %, 5 %, 10 %, 20 %, and 30 % on compressive strength, tensile strength and water absorption of concrete pavers. The result showed that chemically bonded WFS is finer than Natural river sand and has different chemical composition. The water absorption of the blocks containing different proportions of WFS ranged from 4.3 %-4.6 % by mass. The 28 days tensile and compressive strength ranged from 3.15-3.73MPa and 50.5-53.7 MPa, respectively with chemically bonded WFS use but highest in the control mix at 3.79MPa and 61.0MPa respectively. Lastly, the optimal tensile and compressive strengths were observed at 10 % and 20 % chemically bonded WFS use. In conclusion, the higher strengths in the control mix are attributed to the coarser particle size of natural river sand relative to chemically bonded WFS. Also, the use of chemically bonded WFS as fine aggregate achieves concrete strength that is close to that from the control mix. Nonetheless, the replacement of chemically bonded WFS from 10 %-20 % is recommended as it can make concrete paver blocks of the standard quality.