Research On The Damage Of Concrete And The Influence For The Longitudinal Reinforcement Corrosion By Stirrup Corrosion

Reinforcement corrosion is one of the main factors of concrete structure durabilityfailure, Up to now, research on reinforcement corrosion more focused on study oflongitudinal reinforcement corrosion, however the stirrups and longitudinal reinforcementserve together in concrete structures, and mutual influence, the stirrups begin to corrode withtheir effective section areas and mechanical properties reduced. At the same time, the rustforces from those corroded stirrups would damage concrete cover, and stirrup in contact withthe longitudinal reinforcement generate galvanic corrosion, the stirrup corrosion increased andlongitudinal reinforcement corrosion decreased by cathodic protection. So the analysis ofconcrete cover by corrosion of stirrups and its effect on the longitudinal reinforcementcorrosion are important issues for the concrete structures durability research.This paper made30reinforced concrete prism specimens with dimension of150mm×150mm×450mm. making the corrosion test with the natural corrosion method ofconcrete in the general atmospheric environment，it received a protective layer of concretespecimen damage form and the weight loss rate of longitudinal reinforcement and stirrup，itresearched the concrete cover damage law under the influence of protective layer thickness、stirrup diameter and stirrup spacing，and further discusses the effects by three factors forstirrup corrosion. Results show that the thickness of concrete cover, diameter of stirrup andstirrup spacing is smaller, the greater the degree of stirrup corrosion and concrete coverdamage, namely the corrosive crack width is larger, and the influence of the diameter ofstirrup for stirrup corrosion is most sensitive, the influence of protective layer thickness andstirrup spacing on the corrosive crack on protective layer is significant.Based on the data-fitting of stirrup corrosion rate and crack width by the influence ofdifferent parameters, established with the relational model between the stirrup corrosion rateand corrosive crack width by considering the influence of the stirrup diameter and the thickness of protective layer. In accordance with the test of reinforcement corrosion amountunder the influence of different parameters, considering the interactions of the longitudinalreinforcement corrosion and stirrup corrosion, established the amount of longitudinalreinforcement corrosion evaluation model under the influence of the stirrup.