Properties of Self-Compacting Concrete Incorporating Waste Foundry Sand

Abstract

Self-compacting concrete (SCC), a recent innovation in concrete technology, has numerous advantages over conventional concrete. Self-compacting concrete, as the name indicates, is a type of concrete that does not require external or internal compaction, because it becomes levelled and consolidated under its self-weight. SCC can spread and fill all corners of the formwork, purely by means of its self-weight, thus eliminating the need of vibration or any type of consolidating effort . ABSTRACT Foundry sand is a high quality silica sand used as a moulding material by ferrous and nonferrous metal casting industries. It can be reused several times in foundries but, after a certain period, cannot be used further and becomes waste material, referred to as used or spent foundry sand (UFS or SFS). The majority of spent moulding sands are classified as nonhazardous waste (i.e. not corrosive, ignitable, reactive or toxic). This report demonstrates the possibilities of using waste foundry sand as partial replacement of sand in concrete. This experimental investigation was performed to evaluate the strength and durability properties of concrete, in which natural sand was partial replaced with waste foundry sand (WFS). Natural sand was replaced with four percentage (0%, 10%, 15%, 20%) of WFS by weight. Fresh properties of self-compacting concrete were studied. Compression test and splitting tensile strength test were carried out to evaluate the strength properties of concrete at the age of 7, 28, and 56 days. In case of durability properties, sulphate resistance was evaluated at the age of 7, 28 and 56 days and Rapid Chloride Permeability test was conducted at age of 28 days. Test results showed that there is increase in compressive strength, splitting tensile strength of self-compacting concrete by incorporating waste foundry sand (WFS) as partial replacement by sand up to 15%. Resistance of concrete against sulphate attack and rapid chloride permeability were also improved for concrete mixes. Test results indicated that there was better enhancement in strength and durability properties of concrete up to 15% replacement of fine aggregate with WFS.