Ice-Formation Expansion of Salt Solution and its Effect on Frost Damage of Concrete

Abstract:

In order to explain the deterioration mechanism of air entrained concrete subjected to freeze-thaw cycles in water, NaCl, Na₂SO₄ and composite solution, The damage of concrete and ice-formation expansion of salt corrosion solution are tested. The experimental results show that the damage degree of concrete under salt frost is NaCl solution>composite solution>water>Na₂SO₄ solution. Considering the chloride penetrated into concrete and following 2^nd Fick’s Law, the ice-formation expansion resulted by NaCl solution in surface layer of concrete is higher than that in inner, and the expansion stress at outer layer is 1.73 times of that at inner layer according to the proposed function. The expansion stress difference between the internal and external layer causes spalling damage of concrete in chloride salt frost. The ice-formation expansion of Na₂SO₄ solution increases with its raising concentration and it is higher than that of NaCl solution at the same temperature. However, the corrosion products are ettringite and gypsum after sulfate salt frost, and the volume of solid corrosion products is barely change, or even reducible.

• Periodical: Key Engineering Materials (Volume 633)
• Pages: 281-285
• DOI: https://doi.org/10.4028/www.scientific.net/KEM.633.281
• Online since: November 2014
• Authors: Zu Quan Jin, Tie Jun Zhao, Song Gao, Su Yuan Zhang
• Keywords: Concrete, Damage of Pore, Ice-Formation Expansion, Salt Frost

References

[1] Yang Quanbing. Effects of sodium chloride concentration on saturation degree in concrete under freezing-thaw cycles, Journal of the Chinese Ceramic Society, 35(2007) 96-100.

[2] Kejin Wang, Daniel E. Nelsen, Wilfrid A. Nixon. Damaging effects of deicing chemicals on concrete materials, Cement & Concrete Composites, 28(2006) 173-188.

DOI: 10.1016/j.cemconcomp.2005.07.006

[3] Parviz Soroushian, Mohamed Elzafraney. Damage effects on concrete performance and microstructure, Cement & Concrete Composites, 26(2004) 853-859.

DOI: 10.1016/j.cemconcomp.2003.05.001

[4] Bjon Johannesson. Dimensional and ice content changes of hardened concrete at different freezing and thawing temperatures, Cement & Concrete Composites, 32(2010) 73-83.

DOI: 10.1016/j.cemconcomp.2009.09.001

[5] Yang Quanbing. Mechanisms of deicer-frost scaling of concrete (I) capillary-uptake degree of saturation and ice formation pressure, Journal of building materials, 10(2007)522-527.

[6] Josef P. Kaufmann. Experimental identification of ice formation in small concrete pores, Cement and Concrete Research, 34(2004) 1421-1427.

DOI: 10.1016/j.cemconres.2004.01.022

[7] JIN Zuquan, HOU Baorong, Zhao Tiejun, Zhang Peng. Chloride penetration and pore structure of air entrained concrete subjected to freeze-thaw cycles, Journal of Central South University (Science and Technology), 43(2012) 1963-(1968).