Comparative Analysis of Fly Ash-based Geopolymer Concrete and Ordinary Portland Cement Concrete

Abstract

In Pakistan, the high year-over-year growth in the construction industry has led to a significant increase in the cost of construction materials, particularly cement. To reduce the cost of construction, alternative materials need to be sought. In Pakistan, approximately one million tons of fly ash are generated each year from coal-fired thermal power stations. A sample of fly ash was obtained from the 125 Megawatts Coal Fired Power Station Lakhra in Khanot, Hyderabad, Sindh Pakistan.A study was conducted on fly ash-based geopolymer concrete, using test data to identify the factors that influence its properties and to develop a simple method for designing geopolymer concrete mixtures. The mix design for fly ash was carried out using the standard ACI method. Various trial mixes were prepared using arbitrary ratios of cementitious materials, fine and coarse aggregates. The compressive strength of ordinary Portland cement (OPC) concrete was 64% and 57% for geopolymer concrete (GPC) after 7 days. At 14 days, the strength of OPC was 83% and 76% for GPC. The strength of OPC reached 97% after 28 days, while GPC reached 91%.