Utilizing of iron filings in geopolymer mortar as a target for climate change mitigation

Abstract

Industrial waste is increasing consistently with increase of various industries, which leads to environmental pollution. Iron filings (IF) are a type of this waste, that results from cutting and grinding of iron. This research aims to recycle iron filings and use them as a partially sand replacement in construction works to protect the environment from pollution and preserve the depletion of sand as a natural resource. The recent studies investigated performance of cement concrete, mortars and pastes containing iron filings. So, this study aims to investigate the effect of partial replacement of sand by iron filings on properties of geopolymer mortars. On the other hand, the using of geopolymer mortars in this study as a green binder aims to prevent the negative effects of the cement industry. In this study, range of IF (10–50 wt %) was introduced as a replacement of sand in five alkali activated slag mortars activated with sodium hydroxide and sodium silicate solutions. One mixture served as a control without any IF. Different mortar properties such as setting time, flowability, compressive strength, flexural strength, porosity and abrasion resistance were investigated. The results indicated the setting time and flowability decreased as the ratio of IF replacement increased. However, ratio of 10 % IF replacement showed higher values of 38 MPa and 6.2 MPa for compressive and flexural strengths, respectively, and lower values for water absorption and porosity. Introduction IF replacement ratio of (10–30 %) showed enhancement in abrasion resistance, whilst introduction of (40–50 %) showed adverse effect.