Effects of Carbonation on Microscopic Pore Characteristics and Water Absorption Performance of Concrete
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1.Key Laboratory of Performance Evolution and Control for Engineering Structures of the Ministry of Education, Tongji University, Shanghai 200092, China;2.Department of Structural Engineering,Tongji University, Shanghai 200092, China

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TU528.1

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    Abstract:

    Capillary water absorption tests on non-carbonated and carbonated concrete specimens with different water-cement ratios were conducted to investigate the effects of carbonation on capillary water absorption performance of concrete. Mercury intrusion porosimetry (MIP), backscattered electron microscopy (BSE) and thermogravimetric analysis (TGA) were used to identify the pore structure of concrete before and after carbonation. The results show that the water absorption performance of carbonated concrete greatly decreases, and absorption capacity declines by 20.0% to 26.5%, and the water absorption coefficient falls by 30.8% to 37.8%. Compared with non-carbonated concrete, the most probable pore diameter of the carbonated concrete decreases by 13.9 nm to 15.1 nm, with the highest reduction rate reaching 41.8%. The reduction is more significant for concrete with higher water-cement ratios. The carbonation process is found to result in the transformation of calcium hydroxide into calcium carbonate and a decrease in pore diameter. The calculation results indicate that the model proposed by Lucas-Washburn et al. is still effective for carbonated concrete water absorption, and the selection of the most probable pore diameter as the equivalent pore diameter has the best model performance.

    Reference
    [1] 岳清瑞.工程诊治与智慧运维[R].上海:同济大学,2020.YUE Qingrui. Engineering diagnosis and smart operation & maintenance[R] Shanghai: Tongji University, 2020.
    [2] SONG C, JIANG C, GU X L, et al. Calibration analysis of chloride binding capacity for cement-based materials under various exposure conditions[J]. Construction and Building Materials, 2022,314:125588.
    [3] 王昆,屈文俊,李沛豪,等.再碱化后的钢筋混凝土长期电化学研究[J].同济大学学报(自然科学版), 2012, 40(3): 353.WANG Kun, QU Wenjun, LI Peihao, et al. A long-term electrochemical study on carbonated reinforced concrete after realkalisation[J]. Journal of Tongji University (Natural Science), 2012,40(3):353.
    [4] 史才军,卢豹,潘萧颖,等.利用二氧化碳固化技术制备绿色混凝土材料和制品[J].江苏建筑,2018,189(2):14.SHI Caijun, LU Bao, PAN Xiaoying, et al. Preparation of green concrete materials and products with CO2 curing technology[J]. Jiangsu Construction, 2018,189(2):14.
    [5] 史才军,邹庆焱,何富强.二氧化碳养护混凝土的动力学研究[J].硅酸盐学报,2010,38(7):1179.SHI Caijun, ZOU Qingyan, HE Fuqiang. Study on CO2 curing kinetics of concrete[J]. Journal of the Chinese Ceramic Society, 2010,38(7):1179.
    [6] SONG B X, HU X, LIU S H, et al. Chloride binding of early CO2-cured portland cement-fly ash-GGBS ternary pastes[J]. Cement and Concrete Composites, 2022,134:104793.
    [7] BOSANQUET C, LV H. On the flow of liquids into capillary tubes[J]. London, Edinburgh, and Dublin Philosophical Magazine and Journal of Science, 1923,45(267): 525.
    [8] QUERE D. Inertial capillarity[J]. Europhysics Letter, 1997, 39(5): 533.
    [9] 顾祥林,徐宁,黄庆华,等.混凝土结构时间多尺度环境作用研究[J].同济大学学报(自然科学版),2012,40(1):1.GU Xianglin, XU Ning, HUANG Qinghua, et al. Study on temporal multi-scale environmental action for concrete structures[J]. Journal of Tongji University (Natural Science), 2012,40(1):1.
    [10] 张庆章,顾祥林,张伟平,等.混凝土中毛细压力?饱和度关系模型[J].同济大学学报(自然科学版),2012,40(12):1753.ZHANG Qingzhang, GU Xianglin, ZHANG Weiping, et al. Model on capillary pressure-saturation relationship for concrete[J]. Journal of Tongji University (Natural Science), 2012, 40(12):1753.
    [11] FRIES N, DREYER M. An analytic solution of capillary rise restrained by gravity[J]. Journal of Colloid and Interface Science, 2008,320(1): 259.
    [12] LUCAS R. Rate of capillary ascension of liquids[J]. Kolloid Zeitschrift,1918,23(15):15.
    [13] WASHBURN E W. The dynamics of capillary flow[J]. Physical Review, 1921,17:273.
    [14] 阮欣,刘栩,陈艾荣.考虑应力状态的二维混凝土碳化过程数值模拟[J].同济大学学报(自然科学版),2013,41(2):191.RUAN Xin, LIU Xu, CHEN Airong. Two-dimensional numerical simulation of carbonation process with a consideration of stress state[J]. Journal of Tongji University (Natural Science), 2013,41(2):191.
    [15] JIANG C, GU X L, HUANG Q H, et al. Carbonation depth predictions in concrete bridges under changing climate conditions and increasing traffic loads[J]. Cement and Concrete Composites,2018,93:140.
    [16] American Society of Testing and Materials. Standard test method for measurement of rate of absorption of water by hydraulic cement concretes: ASTM C1585-13[S]. Pennsylvania: American Society for Testing and Materials, 2013.
    [17] ZHANG C Y, ZHANG S F, YU J W, et al. Water absorption behavior of hydrophobized concrete using silane emulsion as admixture[J]. Cement and Concrete Research, 2022,154:106738.
    [18] 朱光俊,孙亚琴.传输原理[M].北京:冶金工业出版社,2009.ZHU Guangjun, SUN Yaqin. Principles of transmission[M]. Beijing: Metallurgical Industry Press, 2009.
    [19] ISHIDA T, MAEKAWA K, KISHI T. Enhanced modeling of moisture equilibrium and transport in cementitious materials under arbitrary temperature and relative humidity history[J]. Cement and Concrete Research, 2007,37(4):565.
    [20] WELTY J R, WICKS C E, WILSON R E, et al. Fundamentals of momentum, heat, and mass transfer[M]. 5th ed. New York: John Wiley &Sons, Inc, 2009.
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SONG Chen, JIANG Chao, GU Xianglin. Effects of Carbonation on Microscopic Pore Characteristics and Water Absorption Performance of Concrete[J].同济大学学报(自然科学版),2024,52(4):567~573

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  • Received:April 19,2023
  • Online: April 30,2024
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