Fractal characteristics and damage evaluation of corroded beams under four-point bending tests based on acoustic emission techniques

•Proposed a modified damage evolution model of corroded reinforced concrete beams based on the acoustic emission technique.•Three damage stages can be determined by the acoustic emission ringing counts and strength deterioration behavior.•The acoustic emission fractal dimension analysis could well reflect the whole stage's crack development.•The trends of fractal dimension values provide an early warning point for the corroded beam's failure.