Recycle option for metallurgical by-product (Spent Foundry Sand) in green concrete for sustainable construction

Abstract

Reuse of waste materials as construction material is very much essential to achieve sustainable construction. Utilization of waste materials as construction material not only help in protection of environment but also result in monetary savings. Spent Foundry Sand (SFS) is the waste material generated by metal casting industry. This paper presents study on economic and environmental benefits of recycling of SFS in concrete as sand replacement. Strength and durability properties of green concrete made with SFS as sand replacement are also presented. Natural sand in concrete was replaced with SFS at 0, 5, 10, 15 and 20% replacement levels by weight. To assess the performance of green concrete made with SFS, compressive strength, splitting tensile strength, deicing salt resistance and chloride permeability tests were performed. At age of 28 days, green concrete mixtures containing SFS as sand replacement displayed up to 26% and 12.87% improvement in compressive strength and splitting tensile strength over that of control concrete, respectively. Similarly, concrete mixtures made with SFS exhibited 7.2–17.7% lower chloride ion penetration and 6.6–26.42% improvement in salt scaling resistance on use of SFS. The green concrete mixtures showed very slight scaling after 50 cycles of freezing and thawing in the presence of deicing salt compared to slight to moderate scaling shown by control concrete. The incorporation of up to 20% SFS as sand replacement results improvement in strength and durability properties of green concrete over those of control concrete. Green concrete made with SFS is economical and reduces negative impact on environment by reducing CO2 emissions.