Deterioration progress and performance reduction of 40-year-old reinforced concrete beams in natural corrosion environments

Deterioration progress and performance reduction were experimentally evaluated in 40-year-old corroded reinforced concrete (RC) beams. The corrosion process was natural, without acceleration by current application, admixture inclusion, or exposure to an artificial chloride environment. The mechanical performance of the beams was evaluated through a four-point bending test. The corroded steel reinforcing bars were extracted for corrosion evaluation and tensile testing. A good correlation was established between crack width and cross-section loss, as well as between cross-section loss and ultimate capacity loss. Furthermore, the relationship between deterioration progress and performance degradation with the exposure period for each deterioration stage was elucidated.