Evaluating Sulphate Resistance of Cement-Based Systems by Sulphate Content Determination after Exposure

Abstract:

This paper describes approaches to evaluating the resistance of cement-based composites to sulphate attack. The conventional approach of evaluation by means of measuring expansion is discussed in comparison with the sulphate diffusion, which was quantified as a function of depth. Besides CSA Types GU and HS, a 30:70 blend of fly ash and cement Type GU was also examined. The specimens so produced were immersed in a sulphate solution as per ASTM C1012 and retrieved variously after 7, 14, 28, 56 and 84 days of exposure. As expected, Type HS cement performed best with minimum expansion and sulphate ingress. On the other hand, the Type GU cement showed lower expansion and sulphate ingress in comparison to the fly ash blended binder. Although bearing identical porosity, the blended binder had the smallest median pore size. Therefore, the sulphate ingress and consequent ettringite production likely cracks the blended system more than the other two. Significantly, after longer durations of sulphate exposure, the blended system showed higher tensile strength which implies a healing of cracks through ettringite formation.

• Periodical: Key Engineering Materials (Volume 711)
• Pages: 1037-1044
• DOI: https://doi.org/10.4028/www.scientific.net/KEM.711.1037
• Online since: September 2016
• Authors: Vivek Bindiganavile*, Chi Qian Ou, Zheng Chen, Yaman Boluk
• Keywords: Cement-Based Composites, Compressive Strength, Expansion, Fly Ash, Pore Size Refinement, Splitting Tensile Strength, Sulphate Ingress

References

[1] Mamun M, Bindiganavile V. Sulphate resistance of fibre reinforced cement-based foams. Construction and Building Materials. 2011; 25(8): 3427-42.

DOI: 10.1016/j.conbuildmat.2011.03.034

[2] Santhanam M, Cohen MD, Olek J. Effects of gypsum formation on the performance of cement mortars during external sulfate attack. Cement and Concrete Research. 2003; 33(3): 325-32.

DOI: 10.1016/s0008-8846(02)00955-9

[3] C114-13 A. Standard Test Methods for Chemical Analysis of Hydraulic Cement,. ASTM International, West Conshohocken, PA. (2013). p.32. DOI: 10. 1520/C0114-13.

[4] Wang JG. Sulfate attack on hardened cement paste. Cement and Concrete Research. 1994; 24(4): 735-42.

DOI: 10.1016/0008-8846(94)90199-6

[5] Tixier R, Mobasher B. Modeling of damage in cement-based materials subjected to external sulfate attack. I: formulation. Journal of Materials in Civil Engineering. 2003; 15(4): 305-13.

DOI: 10.1061/(asce)0899-1561(2003)15:4(305)

[6] Tixier R, Mobasher B. Modeling of damage in cement-based materials subjected to external sulfate attack. II: Comparison with experiments. Journal of Materials in Civil Engineering. 2003; 15(4): 314-22.

DOI: 10.1061/(asce)0899-1561(2003)15:4(314)

[7] Al-Amoudi OSB. Attack on plain and blended cements exposed to aggressive sulfate environments. Cement and Concrete Composites. 2002; 24(3): 305-16.

DOI: 10.1016/s0958-9465(01)00082-8

[8] Torii K, Kawamura M. Effects of fly ash and silica fume on the resistance of mortar to sulfuric acid and sulfate attack. Cement and Concrete Research. 1994; 24(2): 361-70.

DOI: 10.1016/0008-8846(94)90063-9

[9] Torii K, Taniguchi K, Kawamura M. Sulfate resistance of high fly ash content concrete. Cement and Concrete Research. 1995; 25(4): 759-68.

DOI: 10.1016/0008-8846(95)00066-l

[10] Tian B, Cohen MD. Does gypsum formation during sulfate attack on concrete lead to expansion? Cement and Concrete Research. 2000; 30(1): 117-23.

DOI: 10.1016/s0008-8846(99)00211-2

[11] C39/39M-14a A. Standard Test Method for Compressive Strength of Cylindrical Concrete Specimens,. ASTM International, W. Conshohocken, PA. (2014). p.7.

[12] C496/C496M-11 A. Standard Test Method for Splitting Tensile Strength of Cylindrical Concrete Specimens,. ASTM International, West Conshohocken, PA. (2011). p.5.

[13] C1012/1012M-13 A. Standard Test Method for Length Change of Hydraulic-Cement Mortars Exposed to a Sulfate Solution,. ASTM International, West Conshohocken, PA. (2013). p.8.

DOI: 10.1520/c1012-03

[14] C265-08 A. Standard Test Method for Water-Extractable Sulfate in Hydrated Hydraulic Cement Mortar,. ASTM International, West Conshohocken, PA. (2008). p.3. DOI: 10. 1520/C0265-08.

DOI: 10.1520/c0265-99

[15] Sahmaran M, Kasap O, Duru K, Yaman I. Effects of mix composition and water–cement ratio on the sulfate resistance of blended cements. Cement and Concrete Composites. 2007; 29(3): 159-67.

DOI: 10.1016/j.cemconcomp.2006.11.007

[16] Santhanam M, Cohen MD, Olek J. Mechanism of sulfate attack: a fresh look: part 1: summary of experimental results. Cement and Concrete Research. 2002; 32(6): 915-21.

DOI: 10.1016/s0008-8846(02)00724-x

[17] Detwiler, RJ, Mehta, PK. Chemical and physical effects of silica fume on the mechanical behaviour of concrete. ACI Mater. J. 86(6): 609-614.