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The effects of both steel corrosion and repeated loading on performance of reinforced concrete beam were investigated. Repeated loads were applied to corroded reinforced concrete specimens with corrosion levels ranging from 0% to 5%. The experiments were conducted for the deflection, cracking, stiffness, bearing capacity and failure type of the corroded beams. For corrosion levels less than 5%, the residual deflection was about 3% of the maximum value of failure deflection. The deflection of beams of high corrosion levels were generally greater than those of low corrosion levels, while the flexural rigidity of the high corrosion levels decreased more in value than those of low corrosion levels. The failure modes of beams changed from plastic type to brittle type with the increase of corrosion level.

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The presence of chloride ions causes reinforced-concrete (RC) bridge piers in a corrosive environment to suffer from different degrees of corrosion damage. Investigation of the seismic performance of corroded RC bridge piers using cyclic loading is therefore of great value. In total, eight RC column pier specimens were experimentally investigated for their seismic performance and the influence of steel corrosion and axial repeated loading on that performance. It was demonstrated that corrosion had a significant influence on yield strength and ultimate load-bearing capacity of the column piers. Compared with non-corroded specimens, the load-bearing capacity was 18·27% lower when the corrosion of the longitudinal steel bar was 7·16%. Axial repeated loading had no significant influence on mechanical properties of the piers. Finite-element analysis was conducted to assess the effect of different parameters on the seismic performance of the piers, including concrete strength, longitudinal reinforcement ratio, axial compression ratio, height of column and stirrup ratio. As the ratio of axial compression stress to the strength was increased from 0·1 to 0·4, the maximum load-bearing capacity was increased by 27·3% from 55 kN to 70 kN. However, the ultimate displacement was significantly decreased by 42·9% from 35 mm to 20 mm.

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