Diffusion of chloride ions into concrete under joint action of carbonation and salt spray
1.School of Civil Engineering, Zhengzhou University, Zhengzhou, Henan 450001, China; 2.School of Civil Engineering, Xi′an University of Architecture and Technology, Xi′an, Shaanxi 710055, China; 3.Tianjin Research Institute for Water Transport Engineering, M.O.T., Tianjin 300450, China
Abstract：To investigte the chloride ion erosion of concrete under marine atmospheric environment, the effect of concrete carbonation on chloride ion diffusion was discussed from three aspects of chloride ions concentration, chloride ion diffusion coefficient and concrete pore structure. The results show that free chloride ion content in concrete is enhanced after carbonation, and the decay of chloride ion concentration is slowed down. For ordinary concrete, the enhancement of chloride ion concentration by carbonation is obvious for low water cement ratio concrete. Compared to ordinary concrete with the same watercement ratio, the increasing of chloride ion concentration by carbonation is more obvious for fly ash concrete. The concrete porosity is decreased by carbonation, while the critical pore diameter and most probable pore diameter are increased with increased pore connectivity, resulting in the increase of chloride ion diffusion coefficient of concrete.
2013, Vol. 34 
