Experimental determination of chloride penetration in cracked concrete beams

摘要

Chloride-induced corrosion of reinforcement is one of the major causes of deterioration of reinforced concrete structures. This phenomenon is markedly influenced by the presence of service cracks.In this paper, the influence of flexural cracks on the chloride penetration in concrete was studied.Four cracked concrete beams under sustained loads and one unloaded beam were immersed in the 5% NaCl solution, with the condition of dry-wet cycles.After 15 cycles, the chloride ion content at each cracked section was determined by rapid chloride test (RCT) method. The experimental results indicated that the chloride concentration and the equivalent apparent chloride diffusion coefficient increased with the increase of crack width.Finally, a regressive calculation model of the chloride penetration in the cracked concrete was proposed, and its accuracy was validated by the test results.