Influence of Nanoclay on Concrete Subjected to Freeze-Thaw Cycles and Bond Behavior between Rebar and Concrete

This paper explores the effects of nanokaolinite clay (NKC) on the behavior of cement-based materials concrete. The resistance of NKC modified cement-based materials to freezing-thaw cycles and the corrosion processes of rebar embedded in the concrete were investigated. Ordinary Portland cement was partially substituted with NKC in ratios of 0%, 1%, 3%, and 5% by weight. The Rapid Freeze-Thaw Cabinet was used to measure the resistance of ordinary Portland cement concrete and concrete with clay to deterioration caused by repeated cycles of freezing and thawing, compressive strength were measured at regular intervals. The corrosion conditions of the rebar embedded in the concrete were studied by an electrochemical accelerated penetration system, pullout tests were performed to assess the bond properties including bond-slip curve, ultimate bond strength between concrete and rebar before and after corrosion. It is revealed that the introduction of NKC improves the freeze-thaw resistivity values and bond behavior in the concrete specimens compared to the control concrete; the corrosion of the rebar embedded in the concrete is impeded efficiently.