Mechanical Properties and Freeze-Thaw Cycling Resistance of Magnesium Phosphate Cement Mortar Prepared at Low Temperatures in Highland Regions
CHEN Xin1, LIU Wen1, CUI Anqi1, ZHENG Haitao2, HUANG Xin1, YANG Wencui1, GE Yong1,*
1 School of Transportation Science and Engineering, Harbin Institute of Technology, Harbin 150090, China 2 Zhengzhou Engineering Co., Ltd., of China Railway Seventh Group, Zhengzhou 450052, China
Abstract: Magnesium phosphate cement mortar is particularly suitable for repairing damaged concrete structures in high-and-cold regions due to its outstanding strength development potential at low temperatures and its characteristic of not requiring heat retention and moisture preservation for curing. The study utilized on-site experimental methods, employing variables such as molding temperature, magnesium-phosphate mass ratio, and curing mode, to investigate the flexural and compressive strengths of magnesium phosphate cement mortar under various conditions at different ages, thereby clarifying the development patterns of its mechanical properties in high-altitude and low-temperature conditions. Further, the study identified the factors affecting the freeze-thaw cycling resistance of magnesium phosphate cement mortar formed at low temperatures in high-altitude regions, using molding altitude, temperature, and magnesium-phosphate mass ratio as variables, and air-void structure and water saturation as intermediate indicators. The scaled mass of the surface exposed to salt solution during unilateral freeze-thaw cycles and changes in relative mass and dynamic elastic modulus during freeze-thaw cycles were used as direct indicators. The findings reveal that natural curing, compared to constant low-temperature curing, is beneficial for early strength development but has a negative impact on later strength development. Low-temperature forming benefits the later strength of magnesium phosphate cement mortar under natural curing. Each of the molding altitude, temperature, and magnesium-phosphate mass ratio of mortar negatively correlates with the air content, but positively correlates with the air-void bubble spacing coefficient and water saturation. Under experimental conditions, lower values of these three variables enhance the mortar's freeze-thaw cycling resistance. A molding temperature of -10 ℃ with a magnesium-phosphate mass ratio of 4 is most beneficial for mortar strength, while a ratio of 3 is most advantageous for freeze-thaw cycling resistance. These research outcomes provide technical recommendations and theoretical support for the application of magnesium phosphate cement mortar in high-and-cold regions.
1 Zhou C H, Cheng W M, Qian J K, et al. Journal of Geo-Information Science, 2019, 11(6), 707 (in Chinese). 周成虎, 程维民, 钱金凯, 等. 地球信息科学学报, 2019, 11(6), 707. 2 Long X J, Li X J. Scientia Geographica Sinica, 2017, 37(10), 1577 (in Chinese). 龙晓君, 李小建. 地理科学, 2017, 37(10), 1577. 3 Chen X, Liu X, Tian B, et al. Materials, 2020, 13(18), 3975. 4 Ge X. The research on effect of plateau climatic conditions on concrete performance and cracking mechanism. Ph. D. Thesis, Harbin Institute of Technology, China, 2019 (in Chinese). 葛昕. 高原气候条件对混凝土性能及开裂机制影响的研究. 博士学位论文, 哈尔滨工业大学, 2019. 5 Zhong X H, Li H J, Ye Y S, et al. In:Symposium for 10th Anniversary of the Qinghai-Tibet Railway Service. Lhasa, 2016, pp.38 (in Chinese). 仲新华, 李化建, 叶阳升, 等. 青藏铁路运营十周年学术研讨会论文集. 拉萨, 2016, pp.38. 6 Tian B, Li L H, Ge Y, et al. Plateau concrete, China Communications Press, China, 2022, pp.1(in Chinese). 田波, 李立辉, 葛勇, 等. 高原混凝土, 中国交通出版社, 2022, pp.1. 7 Liu X, Chen X, Tian B, et al. Journal of the Chinese Ceramic Society, 2021, 49(8), 1743 (in Chinese). 刘旭, 陈歆, 田波, 等. 硅酸盐学报, 2021, 49(8), 1743. 8 Chen X, Liu X, Feng Y R, et al. Journal of Building Engineering, 2023, 72, 106663. 9 Wang P M, Li N, Xu L L, et al. Journal of the Chinese Ceramic Society, 2017, 45(2), 242 (in Chinese). 王培铭, 李楠, 徐玲琳, 等. 硅酸盐学报, 2017, 45(2), 242. 10 Lyu Y, Bai E L, Wang Z H, et al. Materials Reports, 2023, 37(Z2), 22090233 (in Chinese). 吕炎, 白二雷, 王志航, 等. 材料导报, 2023, 37(Z2), 22090233. 11 Haque M A, Chen B. Construction and Building Materials, 2019, 211, 885. 12 Jia X W, Li J M, Wang P, et al. Construction and Building Materials, 2019, 229, 116927. 13 Huang X M, Liu G D, Zheng Y Z Z, et al. Journal of Building Engineering, 2023, 76, 107278. 14 Yuan J, Zhang Z C, Chen X, et al. Concrete, 2022(8), 10 (in Chinese). 袁杰, 张志超, 陈歆, 等. 混凝土, 2022(8), 10. 15 Jia X W, Luo J Y, Zhang W X, et al. Materials, 2020, 13 (23), 5587. 16 Yuan J, Huang X, Chen X, et al. Construction and Building Materials, 2022, 345, 128337. 17 Yang Q B, Zhang S Q, Wu X L. Cement and Concrete Research, 2022, 32, 165. 18 Ma C, Chen B. Construction and Building Materials, 2016, 113, 255. 19 Zeng X H, Lan X L, Zhu H S, et al. Cement and Concrete Composites, 2021, 122, 104139. 20 Zuo S H, Yuan Q, Huang T J, et al. Cement and Concrete Composites, 2023, 135, 104848. 21 Liu X, Chen X, Li L H, et al. Journal of Harbin Institute of Technology, 2021, 53(9), 26 (in Chinese). 刘旭, 陈歆, 李立辉, 等. 哈尔滨工业大学学报, 2021, 53(9), 26. 22 Chen X, Liu X, Li L H, et al. Materials Reports, 2022, 36(12), 20100140 (in Chinese). 陈歆, 刘旭, 李立辉, 等. 材料导报, 2022, 36(12), 20100140. 23 Zhang A, Yang W C, Ge Y, et al. Construction and Building Materials, 2020, 249, 118787. 24 Materak K, Wieczorek A, Bednarska D, et al. Construction and Building Materials, 2023, 406, 133400. 25 Chen X, Liu X, Dong S H, et al. Journal of Xi'an University of Architecture & Technology (Natural Science Edition), 2021, 53(2), 202 (in Chinese). 陈歆, 刘旭, 董淑慧, 等. 西安建筑科技大学学报(自然科学版), 2021, 53(2), 202. 26 Ke G J, Zhang J, Tian B, et al. Cement and Concrete Research, 2020, 135, 106142. 27 He R, Yang Z, Gan V J L, et al. Journal of Cleaner Production, 2021, 321, 128783. 28 Lan X L, Zhu H S, Zeng X H, et al. Journal of Building Engineering, 2023, 69, 106179. 29 Shah H A, Yuan Q, Zuo S H. Construction and Building Materials, 2021, 274, 121835. 30 Chen X, Li L H, Liu X, et al. Bulletin of the Chinese Ceramic Society, 2021, 40(4), 1220 (in Chinese). 陈歆, 李立辉, 刘旭, 等. 硅酸盐通报, 2021, 40(4), 1220. 31 Wang Y Z, Yang W C, Zhang A, et al. Cement and Concrete Research, 2024, 175, 107378. 32 Liao T C, Huang X, Yuan J, et al. Ceramics-Silikáty, 2022, 66(4), 540.
渝公网安备50019002502923号 版权所有：《材料导报》编辑部
2024, Vol. 38 
