EXPERIMENTAL STUDY ON THE FROST RESISTANCE DURABILITY OF CONCRETE IN HIGH ALTITUDE AND COLD REGIONS
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摘要: 高海拔寒冷地区具有海拔高、气温低、昼夜温差大等特点。在冻融循环作用下，高海拔寒冷地区混凝土结构容易发生损伤而影响建筑物使用年限，当损伤严重时甚至威胁建筑物的安全。为了研究高海拔寒冷地区混凝土的工作性能、力学性能、抗冻耐久性以及冻融损伤机理，在某高海拔寒冷地区桥梁施工项目制作了4种不同混凝土试件，开展了混凝土冻融循环试验，并对不同冻融循环次数下的高寒混凝土试件进行了核磁共振试验。结果表明：从宏观力学性能来看，高寒引气减水混凝土的抗冻耐久性表现最佳。同时，4种高寒混凝土试件的抗冻耐久性与混凝土内部的小孔(<0.01 μm)和中孔(0.01 μm~0.05 μm)所占比例密切相关，即高寒混凝土内部的小孔和中孔所占比例越大，混凝土抗冻耐久性越好。Abstract: The cold regions at high altitude have the characteristics of high altitude, low temperature and large temperature difference between day and night. Under the action of freeze-thaw cycle, the concrete structure is prone to damage in the high altitude and cold regions, which affects the service life of buildings and even threatens the safety of buildings when the damage is serious. To study the working performance, mechanical properties, frost resistance durability and freeze-thaw damage mechanism of concrete in the high altitude and cold regions, four kinds of concrete specimens were produced in a bridge construction project, and the freeze-thaw cycle tests were carried out. At the same time, the Nuclear Magnetic Resonance (NMR) tests of concrete under different freeze-thaw cycles were carried out. The results show that the alpine air-entraining and water-reducing concrete has the best frost resistance durability from the perspective of macroscopic mechanical properties. At the same time, the frost resistance durability of the four alpine concrete specimens is closely related to the proportion of mesopores (<0.01 μm) and micropores (0.01 μm-0.05 μm) inside the concrete, i.e., the proportion of small pores and mesopores in the alpine concrete. A larger proportion leads to a better frost resistance of concrete.
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图 2 混凝土经历冻融循环后达到破坏时的形态
Figure 2. Failure modes of concrete specimens after different freeze-thaw cycles
图 3 混凝土质量损失率随冻融循环次数变化趋势
Figure 3. Relationship between mass loss rate of concrete and freeze-thaw cycles
图 4 混凝土动弹性模量随冻融循环次数变化趋势
Figure 4. Relationship between dynamic elastic modulus of concrete and freeze-thaw cycles
图 5 混凝土超声波波速变化趋势
Figure 5. Relationship between ultrasonic wave velocity and freeze-thaw cycles
图 6 混凝土抗折强度损失率随冻融循环次数变化趋势
Figure 6. Relationship between loss rate of flexural strength of concrete and freeze-thaw cycles
图 7 混凝土试件弛豫时间(T2谱)图
Figure 7. Relaxation time (T2 spectrum) diagram of concrete specimen
图 8 不同混凝土冻融破坏前后孔隙大小分布
Figure 8. Pore size distribution of different concrete before and after freeze-thaw damage
图 9 不同混凝土冻融破坏前后孔隙大小分布
Figure 9. Pore size distribution of different concrete before and after freeze-thaw damage
表 1 高寒混凝土配合比与强度
Table 1. Mix ratio and strength of cold-resistant concrete
配合比 水泥/(kg/m3) 碎石/(kg/m3) 砂子/(kg/m3) 水/(kg/m3) 引气剂/(kg/m3) 减水剂/(kg/m3) 抗折强度/MPa 抗压强度/MPa 高寒普通混凝土(P) 458 1046 641 165 0.00 0.00 8.66 52.7 高寒减水混凝土(J) 458 1046 641 165 0.00 4.58 10.44 55.4 高寒引气混凝土(Y) 485 1032 633 160 0.05 0.00 8.18 51.9 高寒引气减水混凝土(YJ) 485 1032 633 160 0.04 4.23 8.93 54.1 
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表 2 高寒混凝土试件工况表
Table 2. Working conditions of cold-resistant concrete
冻融次数 高寒普通混凝土 高寒减水混凝土 高寒引气混凝土 高寒引气减水混凝土 0次冻融循环 P-1~P-3 J-1~J-3 Y-1~Y-3 YJ-1~YJ-3 25次冻融循环 P-4~P-6 J-4~J-6 Y-4~Y-6 YJ4~YJ-6 ··· ··· ··· ··· ··· 175次冻融循环 P-22~P-24 J-22~J-24 Y-22~Y-24 YJ-22~YJ-24 200次冻融循环 P-25~P-27 J-25~J-27 Y-25~Y-27 YJ-25~YJ-27
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[1] 张一奔, 徐飞, 郑山锁. 冻融损伤混凝土研究综述[J]. 混凝土, 2021(3): 10 − 14. doi: 10.3969/j.issn.1002-3550.2021.03.003ZHANG Yiben, XU Fei, ZHENG Shansuo. Review of research on freeze- thaw damage concrete [J]. Concrete, 2021(3): 10 − 14. (in Chinese) doi: 10.3969/j.issn.1002-3550.2021.03.003 [2] 武海荣, 金伟良, 张锋剑, 等. 关注环境作用的混凝土冻融损伤特性研究进展[J]. 土木工程学报, 2018, 51(8): 37 − 46. doi: 10.15951/j.tmgcxb.2018.08.005WU Hairong, JIN Weiliang, ZHANG Fengjian, et al. A state-of-the-art review on freeze-thaw damage characteristics of concrete under environmental actions [J]. China Civil Engineering Journal, 2018, 51(8): 37 − 46. (in Chinese) doi: 10.15951/j.tmgcxb.2018.08.005 [3] 武海荣, 金伟良, 延永东, 等. 混凝土冻融环境区划与抗冻性寿命预测[J]. 浙江大学学报(工学版), 2012, 46(4): 60 − 67. doi: 10.3785/j.issn.1008-973X.2012.04.012WU Hairong, JIN Weiliang, YAN Yongdong, et al. Environmental zonation and life prediction of concrete in frost environments [J]. Journal of Zhejiang University (Engineering Science), 2012, 46(4): 60 − 67. (in Chinese) doi: 10.3785/j.issn.1008-973X.2012.04.012 [4] 宇晓, 张莹秋, 袁书成, 等. 混凝土抗冻耐久性研究进展[J]. 混凝土, 2017(4): 15 − 20. doi: 10.3969/j.issn.1002-3550.2017.04.005YU Xiao, ZHANG Yingqiu, YUAN Shucheng, et al. Review on frost resistance durability of different concrete m aterials [J]. Concrete, 2017(4): 15 − 20. (in Chinese) doi: 10.3969/j.issn.1002-3550.2017.04.005 [5] CHEN J X, DENG X H, LUO Y B, et al. Investigation of microstructural damage in shotcrete under a freeze-thaw environment [J]. Construction and Building Materials, 2015, 83: 275 − 282. doi: 10.1016/j.conbuildmat.2015.02.042 [6] JGJ 55−2011, 普通混凝土配合比设计规程[S]. 北京: 中国建筑工业出版社, 2011.JGJ 55−2011, Specification for mix proportion design of ordinary concrete [S]. Beijing: China Architecture and Architecture Press, 2011. (in Chinese) [7] 惠洪义, 邹通, 王超. 高寒地区超宽箱梁C50高性能混凝土配合比设计与应用[J]. 公路, 2017(2): 188 − 191.HUI Hongyi, ZOU Tong, WANG Chao. Mix proportion design and application of C50 High Performance Concrete for super wide box girder in Alpine Area [J]. Highway, 2017(2): 188 − 191. (in Chinese) [8] 张凯, 杨子江, 王起才, 等. −3℃养护下灌注桩引气混凝土抗压强度及抗冻性研究[J]. 兰州交通大学学报, 2018, 37(6): 20 − 25, 48. doi: 10.3969/j.issn.1001-4373.2018.06.004ZHANG Kai, YANG Zijiang, WANG Qicai, et al. Study on compressive strength and frost resistance of entrained concrete of pile under −3℃ curing [J]. Journal of Lanzhou Jiaotong University, 2018, 37(6): 20 − 25, 48. (in Chinese) doi: 10.3969/j.issn.1001-4373.2018.06.004 [9] 时旭东, 汪文强, 田佳伦. 不同强度等级混凝土遭受超低温冻融循环作用的受压强度试验研究[J]. 工程力学, 2020, 37(2): 211 − 220, 240. doi: 10.6052/j.issn.1000-4750.2019.03.0148SHI Xudong, WANG Wenqiang, TIAN Jialun. Experimental study on compressive strength of concrete with different strength grades subjected to cryogenic freezing-thawing cycles [J]. Engineering Mechanics, 2020, 37(2): 211 − 220, 240. (in Chinese) doi: 10.6052/j.issn.1000-4750.2019.03.0148 [10] SUZUKI T, OGATA H, TAKADA R, et al. Use of acoustic emission and X-ray computed tomography for damage evaluation of freeze-thawed concrete [J]. Construction and Building Materials, 2010, 24: 2347 − 2352. doi: 10.1016/j.conbuildmat.2010.05.005 [11] SICAT E, GONG F, UEDA T. Experimental investigation of the deformational behavior of the interfacial transition zone (ITZ) in concrete on freezing-thawing cycles [J]. Construction and Building Materials, 2014, 65: 122 − 131. doi: 10.1016/j.conbuildmat.2014.04.035 [12] CHEN Y, CEN G P, CUI Y H. Comparative study on the effect of synthetic fiber on the preparation and durability of airport pavement concrete [J]. Construction and Building Materials, 2018, 184: 34 − 44. doi: 10.1016/j.conbuildmat.2018.06.223 [13] TAMON U, MUTTAQIN H, KOHEI N, et a1. Mesoscale simulation of influence of frost damage on mechanical properties of concrete [J]. Journal of Materials in Civil Engineering, 2009, 21(6): 244 − 252. doi: 10.1061/(ASCE)0899-1561(2009)21:6(244) [14] KENNY N, SUN Y, DAI Q L, et al. Investigation of internal frost damage in cementitious materials with micromechanics analysis, SEM imaging and ultrasonic wave scattering techniques [J]. Construction and Building Materials, 2014, 50: 478 − 485. doi: 10.1016/j.conbuildmat.2013.09.061 [15] CHEN J X, ZHAO P Y, LUO Y B, et al. Damage of shotcrete under freeze-thaw loading [J]. Journal of Civil Engineering and management, 2017, 23(5): 583 − 593. doi: 10.3846/13923730.2016.1210224 [16] 李雪峰. 青藏高原地区混凝土抗冻设计及预防措施研究[D]. 南京: 东南大学, 2015.LI Xuefeng. Anti-frost design method and preventive measures for concrete structure in the Qinghai-tibet plateau [D]. Nanjing: Southeast University, 2015. (in Chinese) [17] 米永刚, 刘云贺. 高寒地区高性能混凝土配合比设计与耐久性研究[J]. 混凝土, 2020(7): 92 − 95. doi: 10.3969/j.issn.1002-3550.2020.07.022MI Yonggang, LIU Yunhe. Research on mix design and durability of high performance concrete in alpine region [J]. Concrete, 2020(7): 92 − 95. (in Chinese) doi: 10.3969/j.issn.1002-3550.2020.07.022 [18] 张凯, 王起才, 杨子江, 等. 多年冻土季节活动层区引气混凝土孔结构演变规律与抗冻性研究[J]. 硅酸盐通报, 2019, 38(3): 609 − 614. doi: 10.16552/j.cnki.issn1001-1625.2019.03.004ZHANG Kai, WANG Qicai, YANG Zijiang, et al. Evolution law of the pore structure and the frost resistance of the air-entraining concrete in seasonal frozen regions [J]. Bulletin Of The Chinese Ceramic Society, 2019, 38(3): 609 − 614. (in Chinese) doi: 10.16552/j.cnki.issn1001-1625.2019.03.004 [19] 罗大明, 牛荻涛, 苏丽. 荷载与环境共同作用下混凝土耐久性研究进展[J]. 工程力学, 2019, 36(1): 1 − 14, 43. doi: 10.6052/j.issn.1000-4750.2018.11.ST11LUO Daming, NIU Ditao, SU Li. Research progress on durability of concrete under load and environment [J]. Engineering Mechanics, 2019, 36(1): 1 − 14, 43. (in Chinese) doi: 10.6052/j.issn.1000-4750.2018.11.ST11 [20] 张艺欣, 郑山锁, 裴培, 等. 钢筋混凝土柱冻融损伤模型研究[J]. 工程力学, 2019, 36(2): 78 − 86. doi: 10.6052/j.issn.1000-4750.2017.11.0791ZHANG Yixin, ZHENG Shansuo, PEI Pei, et al. Study on freezing-thawing damage model of reinforced concrete column [J]. Engineering Mechanics, 2019, 36(2): 78 − 86. (in Chinese) doi: 10.6052/j.issn.1000-4750.2017.11.0791 [21] JTG F30−2014, 普通混凝土长期性能和耐久性能试验方法标准[S]. 北京: 中国建筑工业出版社, 2009.JTG F30−2014, Ordinary concrete long-term performance and durability test method standard [S]. Beijing: China Architecture and Architecture Press, 2009. (in Chinese) [22] 朱林奇, 张冲, 石文睿, 等. 结合压汞实验与核磁共振测井预测束缚水饱和度方法研究[J]. 科学技术与工程, 2016, 16(15): 22 − 29. doi: 10.3969/j.issn.1671-1815.2016.15.004ZHU Linqi, ZHANG Chong, SHI Wenrui, et al. Study on the method of prediction of irreducible water saturation by combining mercury intrusion and NMR logging data [J]. Science Technology and Engineering, 2016, 16(15): 22 − 29. (in Chinese) doi: 10.3969/j.issn.1671-1815.2016.15.004 -
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