EFFECT OF SLAG AND GLASS ON CONCRETE PROPERTIES

Abstract

New innovative ways are being developed to recycle by-products and waste material in concrete that otherwise would end up in landfill. Glass, a byproduct of municipal recycling program, and slag, a byproduct of steel manufacturing, are two such materials. Therefore, the aim of this study was to evaluate the effect of partially substituting sand with glass powder and cement with slag on compressive strength and electrical resistivity of concrete. A total of 16 concrete mixtures including one control with different substitution level of sand with glass and cement with slag were designed and further tested for compressive strength. Portland cement was substituted with 0%, 10%, 20%, 30%, 40% and 50% slag by weight. On the other hand, fine aggregates (or sand) was substituted with glass sand, with level of 20%, 40%, 60%, 80% and 100% by weight. Additional selected mixes were prepared by substituting both cement (20%, 40%, 50%) and fine aggregates (20%, 40%, 60%) with slag and glass, respectively. Cement substitution with slag up to 40% was found to increase the compressive strength of concrete beyond which decrease in strength was noticed. Fine aggregate substitution with glass powder produced concrete weaker than the control specimens. Mixes prepared by substituting 40% cement with slag and 20% fine aggregates with glass powder produced highest strength among all the different combinations of slag and glass containing specimens.