Strength properties and microstructural analysis of self-compacting concrete incorporating waste foundry sand

Waste Foundry Sand (WFS) is a solid waste generated from the metal casting industry. Globally, casting production is about 105 million metric tons per year, about 0.60 ton of WFS is produced per 1 ton of cast steel production. Hence, the yearly production of WFS is approximately 62.64 million metric tons. Therefore, disposal of WFS generated from the casting industry poses serious environmental problems. On the other hand, continuous extraction of natural resources is depleting the environment at a rapid pace increasing the cost of production due to an insufficiency of natural resources. This paper presents the results of an experimental investigation on the influence of waste foundry sand (WFS) as a fine aggregate replacement on the fresh, strength and micro-structural properties of self compacting concrete (SCC). Initially, control SCC was designed and then, fine aggregates were replaced with 5, 10, 15, 20, 25 and 30% of WFS by volume. The fresh state properties of SCC were evaluated using slump flow, T-500, V-funnel-box, and U-box test. Strength and microstructural investigations were carried up to the age of 365 days. Tests results indicate all concrete mixes exhibited the properties of fresh state SCC. The 28-day compressive strength of control SCC was 58 MPa. There was 6.38-18.76% reduction in the strength of SCC with the use of 5-30% WFS at 28 days. Micro-structural results of XRD and SEM validate the experimental results. Hence, WFS could be suitably used in the manufacturing of SCC. (C) 2019 Elsevier Ltd. All rights reserved.