Pore Structure Characteristics and Chloride Ion Corrosion Resistance Mechanism of Coal Gangue Concrete under Drying-Wetting Cycles

Abstract

Abstract: Chloride ion corrosion is an important factor affecting the durability of concrete.The chloride ion corrosion resistance of coal gangue concrete by drying-wetting cycles test was studied, and the effect of coal gangue volume substitution rate (0%, 20%, 40%, 60%) on the chloride ion concentration distribution and apparent diffusion coefficient was analyzed. The pore structure parameters of coal gangue concrete were determined by mercury intrusion porosimetry, and the fractal dimension of pore volume was calculated. The influence of pore structure on chloride ion corrosion resistance of coal gangue concrete was studied. The results show that with the increase of the content of coal gangue, the free chloride ion concentration decreases first and then increases, while the apparent diffusion coefficient increases first and then decreases. Compared with the concrete without coal gangue, when the content of coal gangue is 40%, the compactness of concrete is the best and the fractal dimension of pore volume is the largest. At this moment the chloride ion concentration is the lowest and the chloride ion corrosion resistance of coal gangue concrete is the best. The apparent diffusion coefficient of chloride ion decreases by 35.68%.

Key words: concrete, coal gangue, drying-wetting cycle, chloride ion corrosion, diffusion coefficient, pore structure

CLC Number:

TU528.1

QIU Jisheng, ZHANG Ruyi, HOU Bowen, GUAN Xiao, GAO Xujun, LI Leilei. Pore Structure Characteristics and Chloride Ion Corrosion Resistance Mechanism of Coal Gangue Concrete under Drying-Wetting Cycles[J]. BULLETIN OF THE CHINESE CERAMIC SOCIETY, 2021, 40(12): 3993-4001.

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