An Experimental Study On The Corrosion-Induced Cracking And Crack And Crack Propagation In Concrete Cover

Reinforcement corrosion is one of the most important factors that influence the durability of concrete structures. Therefore, it is of great practical significance to the durability assessment and design of reinforced concrete structures to fully understand the corrosion-induced crack propagation and its effect on the degradation of structural properties.Through an accelerated corrosion test, the experimental phenomena, data, and variations during the accelerated process were observed and recorded. The effects of various factors on the corrosion-induced cracking and crack propagation in the concrete cover are studied. By performing a load-carrying test on concrete members, the failure characteristics and mechanisms of corroded members are analyzed. The conclusions of this study are summarized in the following points:(1) The larger the corrosion current density is, the shorter the time to surface cracking. Increasing the cover depth is beneficial to increase the time to surface cracking. The effect of the water/cement ratio on the time to surface cracking will be evaluated by the ratio of the tensile strength to elastic modulus of concrete.(2) The propagation velocity of cracks increases with an increase in corrosion current density but decreases as the cover depth increases. The water/cement ratio has little influence on the propagation velocity of cracks.(3) The larger the corrosion current density is, the slower the degradation velocity of the load-bearing capacity is. The critical crack width increases as the water/cement ratio increases. The larger the concrete cover depth id, the smaller the effect of the corrosion-induced crack on the load-bearing capacity is.(4) Repeated loading and increasing the corrosion-induced crack width will increase the mid-span deflection of beams. With the increase of the corrosion-induced crack width, the load-bearing capacity of concrete beams does not reduce directly until the critical crack width is surpassed.