Abstract:The damage of PE sheath is the direct cause of the corrosion of steel strand in the cable-stayed cable. In order to study the corrosion morphology and mechanical property degradation of steel strand under different damage forms of the sheath, the mechanical property parameters of corroded steel strand was determined by static tensile test based on the electrochemical accelerated corrosion test. The results show that the corrosion forms of the steel strand under two damage modes of the PE sheath are different. When the PE sheath is damaged circumferentially, the corrosion products accumulate at both ends of the damage port, while when the PE sheath is damaged longitudinally, the corrosion products accumulate on both sides. Through corrosion damage assessment of the steel strand, it is found that the corrosion rate of steel strand increases exponentially with time when the sheath is damaged in the circumferential direction, but linearly when it is damaged longitudinally, indicating that the corrosion damage of the former is more harmful than the latter. The bearing capacity of the corroded steel strand after circumferential damage is smaller than that of the longitudinal damage mode. In terms of elastic modulus and tensile strength, when the damage rate of the steel strand is less than 20% in the circumferential failure, the damage rate of the steel strand decreases rapidly and then decreases slowly, while in the longitudinal failure, the elastic modulus and tensile strength of the corroded steel strand decrease linearly with the damage rate. In the case of circumferential failure of PE casing, the mechanical property loss of corroded steel strand is great, which should be paid attention to in practical engineering.