Effect of Waste Glass Powder as A Pozzolanic Material in Concrete Production

Abstract

Over the years, the construction industry consumes large amount of materials. The negative environmental impact and high cost of cement are reasons for research efforts into discovering suitable replacements for cement in concrete production. Cement manufacturing industry is one of the carbon dioxide emitting sources. The global warming is caused by the emission of greenhouse gases to the atmosphere. Among the greenhouse gases, CO2 contributes about 65% of global warming. The global cement industry contributes about 7% of greenhouse gas emission to the earth's atmosphere. From observations with regard to the ineffective waste disposal practices in Nigeria, glass waste was analyzed and identified as having potential for use in concrete production. Wastes utilization would not only be economical, but may also help to create a sustainable and pollution free environment. In this paper, chemical test was undertaken on waste glass powder, and has been partially replaced in the ratio of 0%, 5%, 7.5%, 10%, 12.5% 15% and 20% by volume of cement in concrete. Fresh concrete tests like slump and compaction factor test were carried out along with hardened concrete tests which compressive strength, split tensile strength, and flexural strength. The result shows that waste glass powder is a suitable replacement for cement in concrete production. The chemical constituents of the WGP were SiO2 (71.30%), Al2O3 (2.4%), Fe2O3 (0.4%), CaO (8.20%), K2O (0.30%), MgO (0.43%), Na2O (10.42), Cr2O3 (0.03), TiO2 (0.20), and V2O5, NiO, MnO, S03 are not detected. Since SiO2, Al2O3, and Fe2O3 have a combined constituent percent in excess of 70% (i.e. 74.10%), WGP meets the requirement of a pozollana in accordance the relevant standards. The WGP concrete gave compressive strength in the range of 21.5 N/mm 2 for 20% ash and 28.8 N/mm 2 for 10% ash as compared to 27.8 N/mm 2 for 0% replacement at 28 days curing period. The result shows that 10% WGP should not be exceeded for a competitive value for compressive strength. The density of WGP-Cement concrete slightly reduced with increase of WGP at above 12.5% replacement, as 20% replacement is reduced by 2.76% as compared to 0% at 28days curing. Further work on the Water Absorption Capacity, permeability and durability parameters of WGP-Cement concrete is recommended.