Magnesium Sulfate Attack Resistance of Mortar with Coral Sand Powder

Abstract

Abstract: This paper investigated the magnesium sulfate resistance of mortar incorporating coral sand powder (CSP) combined with supplementary cementitious materials (SCMs). With erosion in magnesium sulfate (MgSO₄) solution at 5 and 20 ℃ for 365 d, the magnesium sulfate attack resistance of mortar was analyzed through appearance, length change, compressive strength, X-ray diffraction pattern and Fourier transform infrared spectroscopy. It is found that the mortar with CSP deteriorates seriously when it is eroded to 365 d in magnesium sulfate solution at 5 ℃. Sulfate resistantance Portland cement (SRPC) with 20% (mass fraction) CSP exhibits better magnesium sulfate attack resistance than ordinary Portland cement (OPC) with 20% (mass fraction) CSP. Fly ash and slag can effectively improve the magnesium sulfate attack resistance of mortar with CSP at 5 ℃, while silica fume reduces the magnesium sulfate attack resistance at 20 ℃. At 5 ℃, the mortar with CSP mainly undergos magnesium and thaumasite sulfate corrosion accompanied by a small amount of gypsum generation, while at 20 ℃, magnesium and gypsum-type sulfate corrosion mainly occurs.

Key words: coral sand powder, magnesium sulfate attack, thaumasite, fly ash, slag, silica fume

CLC Number:

TU528.01

MA Ying, LI Yuwei, TAI An. Magnesium Sulfate Attack Resistance of Mortar with Coral Sand Powder[J]. BULLETIN OF THE CHINESE CERAMIC SOCIETY, 2024, 43(4): 1380-1387.

References

[1] 路宇, 吴晨洁, 王德志, 等. 复掺再生砂和超细粉煤灰对超高性能混凝土抗硫酸盐侵蚀性能的影响[J]. 硅酸盐通报, 2023, 42(10): 3671-3678.
LU Y, WU C J, WANG D Z, et al. Effect of compounding recycled sand and ultra-fine fly ash on sulfate resistance of ultra-high performance concrete[J]. Bulletin of the Chinese Ceramic Society, 2023, 42(10): 3671-3678 (in Chinese).
[2] LI Y W, MA Y, SHEN X D, et al. Research on sulfate resistance of PC, SRPC and CSAC mortars incorporating coral waste filler[J]. Construction and Building Materials, 2022, 347: 128577.
[3] 张超, 温勇, 李宇航, 等. 内掺白云石水泥基材料抗硫酸盐侵蚀性能[J]. 硅酸盐通报, 2023, 42(7): 2317-2325.
ZHANG C, WEN Y, LI Y H, et al. Sulfate attack resistance of dolomite cement-based materials[J]. Bulletin of the Chinese Ceramic Society, 2023, 42(7): 2317-2325 (in Chinese).
[4] 徐良, 程华才, 马子宸, 等. 机制砂岩性与级配对混凝土抗硫酸盐侵蚀性能的影响[J]. 硅酸盐通报, 2022, 41(6): 1973-1980.
XU L, CHENG H C, MA Z C, et al. Effects of manufactured sand lithology and gradation on sulfate resistance of concrete[J]. Bulletin of the Chinese Ceramic Society, 2022, 41(6): 1973-1980 (in Chinese).
[5] 齐晓, 肖前慧, 邱继生, 等. 冻融循环与硫酸盐侵蚀共同作用下再生混凝土的微观结构研究[J]. 硅酸盐通报, 2023, 42(4): 1194-1204.
QI X, XIAO Q H, QIU J S, et al. Microstructure of recycled aggregate concrete under combined action of freeze-thaw cycles and sulfate attack[J]. Bulletin of the Chinese Ceramic Society, 2023, 42(4): 1194-1204 (in Chinese).
[6] MARTIN L H J, WINNEFELD F, TSCHOPP E, et al. Influence of fly ash on the hydration of calcium sulfoaluminate cement[J]. Cement and Concrete Research, 2017, 95: 152-163.
[7] 杨永敢, 康子豪, 詹炳根, 等. 初始损伤混凝土的抗硫酸盐侵蚀性能[J]. 建筑材料学报, 2022, 25(12): 1255-1261.
YANG Y G, KANG Z H, ZHAN B G, et al. Sulfate resistance of concrete with initial damage[J]. Journal of Building Materials, 2022, 25(12): 1255-1261 (in Chinese).
[8] ROSTAMI M, BEHFARNIA K. The effect of silica fume on durability of alkali activated slag concrete[J]. Construction and Building Materials, 2017, 134: 262-268.
[9] 孔亚宁, 周建伟, 高育欣, 等. 石膏矿渣水泥混凝土抗硫酸钠侵蚀性能研究[J]. 硅酸盐通报, 2022, 41(8): 2844-2850.
KONG Y N, ZHOU J W, GAO Y X, et al. Sodium sulfate corrosion resistance of gypsum slag cement concrete[J]. Bulletin of the Chinese Ceramic Society, 2022, 41(8): 2844-2850 (in Chinese).
[10] HARTSHORN S A, SHARP J H, SWAMY R N. Thaumasite formation in Portland-limestone cement pastes[J]. Cement and Concrete Research, 1999, 29(8): 1331-1340.
[11] TORRES S M, SHARP J H, SWAMY R N, et al. Long term durability of Portland-limestone cement mortars exposed to magnesium sulfate attack[J]. Cement and Concrete Composites, 2003, 25(8): 947-954.
[12] TOSUN K, FELEKOLU B, BARADAN B, et al. Effects of limestone replacement ratio on the sulfate resistance of Portland limestone cement mortars exposed to extraordinary high sulfate concentrations[J]. Construction and Building Materials, 2009, 23(7): 2534-2544.
[13] SKAROPOULOU A, KAKALI G, TSIVILIS S. Thaumasite form of sulfate attack in limestone cement concrete: the effect of cement composition, sand type and exposure temperature[J]. Construction and Building Materials, 2012, 36: 527-533.
[14] WU M, ZHANG Y S, JI Y S, et al. A comparable study on the deterioration of limestone powder blended cement under sodium sulfate and magnesium sulfate attack at a low temperature[J]. Construction and Building Materials, 2020, 243: 118279.
[15] LEE S T, MOON H Y, SWAMY R N. Sulfate attack and role of silica fume in resisting strength loss[J]. Cement and Concrete Composites, 2005, 27(1): 65-76.
[16] DEB S K, MANGHNANI M H, ROSS K, et al. Raman scattering and X-ray diffraction study of the thermal decomposition of an ettringite-group crystal[J]. Physics and Chemistry of Minerals, 2003, 30(1): 31-38.
[17] BARNETT S J, MACPHEE D E, LACHOWSKI E E, et al. XRD, EDX and IR analysis of solid solutions between thaumasite and ettringite[J]. Cement and Concrete Research, 2002, 32(5): 719-730.