Chloride ion Erosion of Cracked Concrete under Load

Abstract

In order to study the effect of load on chloride ion erosion before cracking, cracking critical state and instability failure state, three-point bending beam fracture test was carried out. The specimens were loaded at three loading levels: pre-crack load, crack load and peak load, then chloride ion content in the cracked section of the concrete was measured by borehole sampling method after immersion in 8% sodium chloride solution for 30,60,90 days. The test results show that at the same depth of cracking section, the content of chlorine ion increases with the load level. The chloride ion content with wedge erosion is significantly higher than that without wedge erosion under the same conditions and the increasing trend of chloride ion content under peak load is more significant. The chloride diffusion coefficient decreases with erosion time when the load is less than the initiation load, and chloride ion diffusion coefficient increases slowly with erosion time when load is greater than the initiation load. The stress intensity factor of concrete is positively correlated with chloride ion diffusion coefficient.