Durability of CFRP-steel interface modified by liquid rubber under chlorine salt erosion

Fifty-four carbon fiber reinforced resin composite (CFRP)-steel double lap specimens were designed to study the effects of liquid rubber modifier content and corrosion age on the mechanical properties of CFRP-steel modified interface under the erosion of two kinds of chlorine salts: High temperature water bath and dry-wet cycles at normal temperature. The results show that under the action of high temperature water bath and dry-wet cycles at normal temperature, the unmodified specimens show CFRP interlayer stripping failure and steel/binder interface stripping failure, respectively, while the liquid rubber modified specimens could transform the failure mode into adhesive cohesion failure, among which 10wt% liquid rubber has the best effect on improving interface durability. After 180 days of high temperature water bath and dry-wet cycles chloride salt erosion at normal temperature, the ultimate load retention rates of the specimens increase by 28.11% and 29.94%, respectively, compared with that of the unmodified specimens. Based on the experimental results, modified interface bond-slip models are established which are suitable for two kinds of chlorine salt erosion environments, and the predicted results are in good agreement with the experimental results.