Simulated physicomechanical and Electrochemical Impedance Spectroscopy Assessment of Basalt Powder Waste Added to Portland Cement in Different Corrosive Media

Abstract

A basalt stone-crushing plant's byproduct is basalt powder. Proposing the use of these byproducts presents significant disposal, environmental pollution and health risk issues. Basalt can be employed as a novel mineral additive and had obvious potential for pozzolan activity. This study evaluated basalt powder's (BP) usage as a partial replacement (5, 10, 20%) of ordinary Portland cement (OPC) to enhance cement pastes properties. The conducted investigations were to ascertain physicomechanical properties and corrosion resistance using electrochemical impedance spectroscopy (EIS) of cement pastes with a partial addition of basalt powder in different solutions of 5% NaCl and 5% MgCl2 for up to 270 days. Infra-red spectroscopy (IR), X-ray diffraction (XRD), Scanning Electron Microscopy (SEM) and Energy-dispersive X-ray spectroscopy (EDX) were also performed to investigate the hydration process and microstructure formation of the basalt blended paste. Results showed that replacing OPC with basalt powder improved the compressive strength of cement pastes. This is a result of the addition of basalt powder filler. The results of the BP20% specimen in 5% NaCl showed the highest values of Rp 953 ohms.cm2 after 270 days. This indicates high corrosion resistance as a result of binding by high Al2O3, which reduced free chloride in the solution. Furthermore, the decrease in iron rebar bonds in 5% MgCl2 compared to 5% NaCl showed a highly adherent protective layer developed on the surface of the rebar.