Resistance of Concrete to Na₂SO₄ Freeze-Thaw Cycles and Failure Mechanism Analysis

Abstract:

Rapid freeze–thaw cycle experiments were carried out on concrete specimens with 0.4, 0.5, and 0.6 water–cement (w/c) ratio in 0% (tap water), 1%, and 5% Na₂SO₄ solutions, respectively, to study the performance of ordinary concrete resistance to sulfate freeze–thaw cycle. The specimens underwent visual inspection, and mass losses and relative dynamic elastic modulus (RDEM) were measured regularly. Scanning electron microscope observation and X-ray diffraction analysis were conducted on partial specimens after the freeze–thaw cycle experiment. Research results show that due to the coupling effects of freeze–thaw cycle and sulfate corrosion, freeze–thaw cycles of concrete in Na₂SO₄ solution caused more damages than in tap water. Higher Na₂SO₄ concentration produced severe damages. Concrete with different w/c ratios exhibit different sulfate freeze–thaw cycle resistances, and concrete with lower w/c ratio usually produces stronger resistance. RDEM loss is considered the control index to determine concrete failure. The corrosion products in Na₂SO₄ solution freeze–thaw cycle are mainly ettringite and gypsum. With the increase in Na₂SO₄ concentration, ettringite formation gradually decreases and gypsum formation gradually increases.

• Periodical: Key Engineering Materials (Volume 711)
• Pages: 335-342
• DOI: https://doi.org/10.4028/www.scientific.net/KEM.711.335
• Online since: September 2016
• Authors: Guo Li*, Jian Min Du, Xiao Suo Wu, Kun Yang
• Keywords: Concrete, Failure Mechanism, Freeze-Thaw Cycle, Na₂SO₄, Resistance

References

[1] G.F. Peng, Q. Ma, H.M. Hu, et al., The effects of air entrainment and pozzolans on frost resistance of 50–60 MPa grade concrete, Constr. Build. Mater. 27(2007)1034-1039.

DOI: 10.1016/j.conbuildmat.2006.02.002

[2] B. Łaźniewska-Piekarczyk, The frost resistance versus air voids parameters of high performance self compacting concrete modified by non-air-entrained admixtures, Constr. Build. Mater. 48(2013)1209-1220.

DOI: 10.1016/j.conbuildmat.2013.07.080

[3] A. Neville, The confused world of sulfate attack on concrete, Cem. Concr. Res. 8(2004)1275-1296.

[4] G. Li, J.Z. Chen, D.Q. Guo, Sulfate corrosion of concrete with fly ash or slag in saline soil environment, Journal of Xuzhou Institute of Technology (Natural Science Edition). 30(2015) 70-75. (in Chinese).

[5] J.J. Valenza, G.W. Scherer, A review of salt scaling: I. Phenomenology. Cem. Concr. Res. 37(2007)1007-1021.

[6] J.J. Valenza, G.W. Scherer, A review of salt scaling: II. Mechanisms. Cem. Concr. Res. 37(2007)1022-1034.

[7] A. Amini, S.S. Tehrani, Combined effects of saltwater and water flow on deterioration of concrete under freeze-thaw cycles, J. Cold Reg. Eng. 25(2011)145-161.

DOI: 10.1061/(asce)cr.1943-5495.0000029

[8] C.W. Miao, R. Mu, Q. Tian, W. Sun, Effect of sulfate solution on the frost resistance of concrete with and without steel fiber reinforcement, Cem. Concr. Res. 32(2002)31-34.

DOI: 10.1016/s0008-8846(01)00624-x

[9] H.F. Yu, W. Sun, L.H. Yan, Q. Wang, Research on freezing-thawing durability of air-entrained concrete exposed to salt lakes, Journal of Wuhan University of Technology. 3(2004)15-18. (in Chinese).

[10] R. Mu, C.W. Miao, J.P. Liu, W. Sun, Effect of NaCl and Na2SO4 solution on the frost resistance of concrete and its mechanism, J. Chin. Ceramic Soc. 6(2001)523-529. (in Chinese).

[11] L.D. Yuan, D.T. Niu, L. Jiang, Y.Z. Sun, Q.N. Fei, Study on damage of concrete under the combined action of sulfate attack and freeze-thaw cycle, B. Chin. Ceram. Soc. 6(2013)1171-1176. (in Chinese).

[12] Y.Q. Zhang, H.F. Yu, W. Sun, J.Y. Zhang, Frost resistance of concrete under action of MgSO4 attack, Journal of Building Materials. 5(2011)698-702. (in Chinese).

[13] L. Jiang, D.T. Niu, L.D. Yuan, Q.N. Fei, Durability of concrete under sulfate attack exposed to freeze–thaw cycles, Cold Regions Science and Technology. 112(2015)112-117.

DOI: 10.1016/j.coldregions.2014.12.006

[14] H. Sommer, The precision of the microscopical determination of the air-void system in hardened concrete, Cem. Concr. Aggreg. 1(2)(1979)49-55.

DOI: 10.1520/cca10403j

[15] E. Siebel, Air-void characteristics and freezing and thawing resistance of superplasticized air-entrained concrete with high workability, in: V.W. Malhotra (Ed. ), ACI Special Publication SP-119, 1989, pp.297-319.

DOI: 10.14359/2506

[16] R. Mu, C.W. Miao, J.P. Liu, W. Sun, Effect of sodium sulphate solution on the frost resistance of concrete, Journal of Building Materials. 4(2001)311-316. (in Chinese).

[17] Christiane Foy, Michel Pigeon, Nemkumar Banthia. Freeze-thaw durability and deicer salt scaling resistance of a 0. 25 water-cement ratio concrete. Cem. Concr. Res. 1988, 18(4): 604-614.

DOI: 10.1016/0008-8846(88)90053-1

[18] K. Rose, B.B. Hope, A.K.C. Ip, Statistical analysis of strength and durability of concrete made with different cement, Cem. Concr. Res. 19(1989)476-486.

DOI: 10.1016/0008-8846(89)90036-7

[19] K. Sotiriadis, E. Nikolopoulou, S. Ysivilis, Sulfate resistance of limestone cement concrete exposed to combined chloride and sulfate environment at low temperature, Cem. Concr. Comps. 8(2012)903-910.

DOI: 10.1016/j.cemconcomp.2012.05.006

[20] Y. Ge, W.C. Yang, J. Yuan, B.S. Zhang, A.L. Xiong, Freezing resistance of concrete in sulfate solution, Concrete. 8(2005)71-73. (in Chinese).

[21] X.P. Su, Q. Wang, W.H. Wang, H.Y. Sun, Frost resistance and durability mechanism of concrete under saline-alkali condition in seasonal frozen soil area, Journal of Jilin University: Earth Science Edition. 4(2014)1244-1253. (in Chinese).

[22] L. Jiang, D.T. Niu, Y.Z. Sun, Q.N. Fei, Ultrasonic testing and microscopic analysis on concrete under sulfate attack and cyclic environment, Journal of Central South University. 21(2014) 4723-4731.

DOI: 10.1007/s11771-014-2482-6