Effect of Freezing and Thawing on Chloride Ion Erosion of Fiber Concrete

Abstract

the frost resistance of ordinary concrete is poor, and concrete is often destroyed in the engineering practice at low temperature. This test takes 1% polypropylene fiber concrete as an example to explore the effect of different mix ratio and different freezing thawing times on the diffusion of chloride ion. After repeated freezing and thawing, concrete members will be subjected to structural damage that can not be ignored. As the number of freeze-thaw increases, concrete shows a gradual increase in the mass loss rate and a relative decrease in relative dynamic elastic modulus. Whether or not the freeze-thaw cycle is applied, the chloride penetration of concrete increases with the increase of water cement ratio. In the freezing-thawing environment, the chloride diffusion of concrete increases rapidly with the increase of freeze-thaw times, finally, the least square method is used to fit the second law of Fick, and the mathematical solution of the new equation of chloride diffusion in concrete is obtained.