This paper examines and analyzes the test results produced from a comprehensive test program designed to study the axial behaviour of reinforced concrete columns subjected to steel corrosion under service loads. Several small size concrete columns with various reinforcement configurations were subjected to accelerated corrosion condition in the laboratory. After a target level of corrosion the column specimens were tested to study the failure mode, load-strain behaviour, crack load and ultimate load. The corrosion level was measured based on the loss in weight of the reinforcement1. Uncorroded columns were used as control samples and tested in parallel with the corroded samples.