Mechanical properties of steel corrosion products in reinforced concrete

Abstract

The compressive modulus versus applied compressive stress for steel rebar corrosion products of varying composition and particle size is evaluated by consolidation tests with applied axial pressures of 0–30 MPa. The compressive modulus increases linearly with increasing applied stress, and the corrosion products are increasingly compressed with decreasing particle size under equivalent conditions. The effect of composition on the mechanical properties of corrosion products is not obvious under equivalent conditions. The elastic modulus of the corrosion products was observed to increase more or less linearly with increasing concrete cover thickness for a given concrete grade and steel rebar diameter, and the Poisson’s ratio was observed to decrease more or less linearly under the same condition. Based on elasticity theory, for common concrete grades (C20, C30, C40, C50) and standard values of concrete cover thickness (20–50 mm) and steel rebar diameter (10, 20, 30, 40 mm), the elastic modulus at the initiation of concrete cover cracking due to corrosion expansion is 2.5–30.8 MPa and the Poisson’s ratio is 0.46–0.49.