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Solution transportation in concrete partially exposed to Na2SO4 solution
Wick action is the key factor in understanding the salt weathering of porous materials. In this study, concrete discs were partially exposed to Na2SO4 solution to simulate the wick action in concrete. We evaluated the effects of the relative humidity (RH), solution concentration, and pore structures (different water to cement ratios) on the solution transport mechanism based on the water evaporation rate. Interestingly, we found that lower RH and larger W/C ratio accelerated evaporation, but the higher concentration of the solution slowed it down. The micro-analyzer results of NMR and XRD confirmed that the formation of ettringite and gypsum due to chemical sulfate attack blocked the pores in the concrete, resulting in a decrease in water evaporation. Na2SO4 crystallization distress was not detected in the concrete. Therefore, the solution transport process in the concrete discs could not be described by wick action.
Solution transportation in concrete partially exposed to Na2SO4 solution
Wick action is the key factor in understanding the salt weathering of porous materials. In this study, concrete discs were partially exposed to Na2SO4 solution to simulate the wick action in concrete. We evaluated the effects of the relative humidity (RH), solution concentration, and pore structures (different water to cement ratios) on the solution transport mechanism based on the water evaporation rate. Interestingly, we found that lower RH and larger W/C ratio accelerated evaporation, but the higher concentration of the solution slowed it down. The micro-analyzer results of NMR and XRD confirmed that the formation of ettringite and gypsum due to chemical sulfate attack blocked the pores in the concrete, resulting in a decrease in water evaporation. Na2SO4 crystallization distress was not detected in the concrete. Therefore, the solution transport process in the concrete discs could not be described by wick action.
Solution transportation in concrete partially exposed to Na2SO4 solution
Liu, Zanqun (Autor:in) / Zhu, Jiahui (Autor:in) / Yuan, Qiang (Autor:in) / Wang, Cheng (Autor:in) / Zhang, Fengyan (Autor:in)
Journal of Sustainable Cement-Based Materials ; 9 ; 371-381
01.11.2020
11 pages
Aufsatz (Zeitschrift)
Elektronische Ressource
Englisch
Microstructure Analysis of Concrete Exposed to Acidic Solution
British Library Conference Proceedings | 2011
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