Cracking characteristics of corroded RC beams under repeated loading

The cracking characteristics of corroded reinforced concrete (RC) beams under repeated loading were experimentally studied. A total of 15 test specimens (three non-corroded and 12 corroded RC beams) were investigated. The effects of steel corrosion and repeated loads on the RC beams were evaluated with respect to cracking and failure shape. Beams of different corrosion percentages were evaluated. The results from the experiments indicate that cracking of concrete is generally influenced by corrosion, but the effect is less significant for beams of low corrosion percentages. However, repeated loading had a significant effect on the corroded beams: the number of loading cycles before failure for these beams was less than for the uncorroded beams. It was also found that the crack widths of corroded RC beams increased significantly with steel corrosion percentage under repeated loading, and a relation between crack spacing and steel corrosion level was generated accordingly. The average crack spacing of corroded RC beams tended to increase generally with steel corrosion level under repeated loading.