Damage of Cement Paste in Sulfate Environment with Different Temperature and Drying-Immersion Cycles

Abstract:

Damage of cement paste under attack of sodium sulfate solution with different temperature and regime were carried out in this paper. Experimental study was executed on cement paste admixed by fly ash and GGBS. Sulfate concentration is 33.8g/l SO42- solution (5% by mass of Na2SO4). Two exposure regimes are employed in this study including immersion and drying-immersion cycles. In immersion regime, the temperature of sulfate solution is room temperature, 50°C and 80°C. Physical properties and sulfate ion distribution of paste were systematically tested during 150 days of sulfate exposure. And effects of raised temperature and drying-immersion cycles on deterioration of paste were also determined. The experimental results show that the strength, mass and expansion rate of paste improves initially and then progressively degrade until failure in sulfate environment. Beside chemical attack, which is major damage factor to paste in immersion regime, crystallized thenardite results in surface scaling of paste in drying-immersion cycles. Raised temperature and drying-immersion cycles accelerate the physical properties evolution process and increase the effective sulfate diffusion coefficient.

• Periodical: Applied Mechanics and Materials (Volumes 275-277)
• Pages: 2088-2092
• DOI: https://doi.org/10.4028/www.scientific.net/AMM.275-277.2088
• Online since: January 2013
• Authors: Xue Feng Wu, Zu Quan Jin, Tie Jun Zhao, Song Gao
• Keywords: Cement Paste, Drying-Immersion Cycles, Sulfate, Temperature

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