The combined effect of load and corrosion on the flexural performance of recycled aggregate concrete beams

To investigate the combined effect of load and steel corrosion on the flexural performance of recycled aggregate concrete beams, considering three types of aggregate replacement ratios (i.e., 0%, 50%, and 100%) and four levels of load (i.e., 0, 0.2, 0.4, and 0.6), 12 beams were designed for accelerated corrosion test and four-points bending test. The load was applied to beams by using a designed loading device before the accelerated corrosion test. After the accelerated corrosion test, four-point bending test was conducted to measure the flexural performance of beams. The results showed that, with the increase of load level applied to beams before accelerated corrosion test, the number of bending cracks on the bottom of corroded beams after four-points bending test decreased, while the average spacing of bending cracks increased. The effect of aggregate replacement ratio on the average spacing of bending cracks was more significant than that of steel corrosion. Yield moment capacity and ultimate moment capacity of corroded beams had a strong linear relationship with the maximum mass loss of tensile reinforcement, and both of which decreased with the increase of load level and aggregate replacement ratio. For every 1% maximum mass loss of the tensile reinforcement, the reduction of ultimate moment capacity of beams was approximately 4-6 times larger than that of ordinary concrete beams. The degradation model for ultimate moment capacity of corroded beams proposed in this paper had satisfactory prediction accuracy.

Automated summary

This study investigates the combined effect of load and steel corrosion on the flexural performance of recycled aggregate concrete beams. The results show that the load level and aggregate replacement ratio have an impact on the number and spacing of bending cracks in the beams, and the maximum mass loss of tensile reinforcement has a linear relationship with the ultimate moment capacity of the beams.