Impact of corrosion on axial load capacity of ageing low-strength reinforced concrete columns with different confinement ratios

Abstract

Many ageing structures in earthquake-prone regions are vulnerable to failure by seismic actions resulting from the poor detailing, environmental degradation and quality of materials used. Insufficient column confinement and corrosion of the embedded reinforcement have been identified as some of the problems existing within such structures. This paper summarises the results of an experimental investigation into ageing low-strength short-reinforced concrete (R.C.) columns with varying confinement levels and degrees of corrosion. The latter is introduced in a controlled manner using electrolysis. In total, thirty short R.C. columns (15 square and 15 circular) with three confinement ratios and steel corrosion loss (0% to ~30%) were subjected to monotonic axial load. The experimental results showed rebar buckling was more pronounced at higher corrosion rates and in sparsely confined columns. In addition, the load-carrying capacity of the R.C. columns was significantly affected by corrosion and the degree of confinement.