Microsilica and Waste Glass Powder as Partial replacement of Portland Cement: Electrochemical Study on the Corrosion Performance of Steel Rebar in the Blended Concrete

Abstract

Today, steel reinforced concrete has been extensively used as building material which is typically exposed to corrosive media, causing corrosion of steel rebar. Here, a partial replacement by microsilica (MS) and Waste Glass Powder (WGP) in ordinary Portland cement (OPC) were used to produce reinforced concrete and its effects were investigated on corrosion resistance of carbon steel rebar in 3.5 wt% NaCl solution. Electrochemical impedance spectroscopy measurements were used to study the electrochemical corrosion behavior of carbon steel rebar. The absorption results revealed that the mixtures containing 10% MS and 10% WGP (10MS10WGP) considerably improved water absorption of concrete structure. Partial replacement of OPC by MS, either with or without WGP, revealed a significant increase in both one and four-week compressive strengths. The electrochemical results indicated that the 10MS10WGP specimen has higher value of corrosion resistance than the other samples. The surface of 10MS10WGP shows low corrosion products and thin pits which can be related to the decrease of water absorption and Cl- ion permeability into the concrete structure.