掺氧化镁膨胀剂混凝土的抗硫酸盐侵蚀性能研究

硅酸盐通报 ›› 2022, Vol. 41 ›› Issue (4): 1293-1300.

掺氧化镁膨胀剂混凝土的抗硫酸盐侵蚀性能研究

刘国强¹, 刘来宝²

1.兰州石化职业技术大学材料与土木工程系,兰州 730207;
2.西南科技大学材料科学与工程学院,绵阳 621010

收稿日期:2021-10-19 修回日期:2022-01-23 出版日期:2022-04-15 发布日期:2022-04-27
通讯作者: 刘来宝,博士,教授。E-mail:liulaibao@swust.edu.cn
作者简介:刘国强(1977—),男,副教授。主要从事无机非金属材料制备及应用研究。E-mail:lgq8421129@163.com
基金资助:
国家自然科学基金青年基金(51808464);国家自然科学基金面上项目(51978590)

Sulfate Corrosion Resistance of Concrete Mixed with Magnesia Expansive Agent

LIU Guoqiang¹, LIU Laibao²

1. Department of Material and Civil Engineering, Lanzhou Petrochemical University of Vocational Technology, Lanzhou 730207, China;
2. School of Materials Science and Engineering, Southwest University of Science and Technology, Mianyang 621010, China

Received:2021-10-19 Revised:2022-01-23 Online:2022-04-15 Published:2022-04-27

摘要/Abstract

摘要： 由于环境侵蚀,混凝土结构易开裂破坏,掺入适宜的外加剂可减轻其损伤劣化。本文研究了不同氧化镁膨胀剂掺量对混凝土抗侵蚀性能的影响,测试了混凝土经MgSO₄浸泡后的质量损失、强度变化,结合微观结构变化,评价了掺氧化镁膨胀剂混凝土的抗硫酸盐侵蚀性能。结果表明:硫酸盐长期浸泡环境下,混凝土试件的质量和力学性能均先增加后降低,掺入氧化镁膨胀剂以及降低硫酸盐溶液浓度都能降低硫酸盐的侵蚀速率;氧化镁膨胀剂的掺入一方面能够细化混凝土内部孔结构,降低硫酸盐的侵蚀损伤速率,延缓试件损伤开裂形成微裂纹;另一方面氧化镁膨胀剂填充了开裂后的微裂纹,阻断或减小了硫酸盐继续传输通道,从而抑制裂纹继续扩展。

关键词: 混凝土, 氧化镁膨胀剂, 抗硫酸盐侵蚀性能, 微观结构, 孔径, 损伤速率

Abstract: Due to environmental erosion, concrete structures are easy to crack and damage, and appropriate additives can reduce damage and deterioration. In this paper, the influence of different content of magnesium oxide expansive agent on the corrosion resistance of concrete was studied, the mass loss and strength change of concrete which soaked in MgSO₄ solution were tested. Combined with the microstructure changes, the sulfate corrosion resistance of the concrete mixed with magnesium oxide expansive agent was evaluated. The results show that the mass and mechanical properties of concrete specimens increase first and then decrease in the long-term sulfate immersion environment, and the sulfate damage rate can be reduced by adding magnesium oxide expansive agent and reducing the concentration of sulfate solution. Among them, on the one hand,the addition of magnesium oxide expansive agent refines the internal pore structure of concrete, reduces the rate of sulfate corrosion damage, and delays the damage cracking of specimens to form microcracks; on the other hand, magnesium oxide expansive agent fills the microcracks after cracking, blocking or reducing the sulfate continuous transmission channel, thus hindering the crack propagation.

Key words: concrete, magnesia expansive agent, sulfate corrosion resistance, microstructure, pore size, damage rate

中图分类号:

TU528.042

刘国强, 刘来宝. 掺氧化镁膨胀剂混凝土的抗硫酸盐侵蚀性能研究[J]. 硅酸盐通报, 2022, 41(4): 1293-1300.

LIU Guoqiang, LIU Laibao. Sulfate Corrosion Resistance of Concrete Mixed with Magnesia Expansive Agent[J]. BULLETIN OF THE CHINESE CERAMIC SOCIETY, 2022, 41(4): 1293-1300.

参考文献

[1] 黄冉.西部环境下结构混凝土耐久性研究[D].南京:东南大学,2017.
HUANG R. Durability reaserach of reinforced concrete under the western environment[D]. Nanjing: Southeast University, 2017 (in Chinese).
[2] 白伟亮,李悦.西部地区桥梁空心薄壁高墩混凝土开裂影响综述[J].建筑技术,2017,48(11):1200-1203.
BAI W L, LI Y. Summarization of cracking impact on concrete structure bridge with hollow thin-walled high pier in Western China[J]. Architecture Technology, 2017, 48(11): 1200-1203 (in Chinese).
[3] 田威,李小山,王峰.冻融循环与硫酸盐溶液耦合作用下混凝土劣化机理试验研究[J].硅酸盐通报,2019,38(3):702-710.
TIAN W, LI X S, WANG F. Experimental study on deterioration mechanism of concrete under freeze-thaw cycles coupled with sulfate solution[J]. Bulletin of the Chinese Ceramic Society, 2019, 38(3): 702-710 (in Chinese).
[4] 李涛,朱鹏涛,张彬,等.硫酸盐侵蚀下混凝土内腐蚀反应-扩散过程的实验研究[J].硅酸盐通报,2020,39(1):50-55.
LI T, ZHU P T, ZHANG B, et al. Experimental study on corrosion reaction-diffusion process of concrete under sulfate attack[J]. Bulletin of the Chinese Ceramic Society, 2020, 39(1): 50-55 (in Chinese).
[5] 韩宇栋,张君,高原.混凝土抗硫酸盐侵蚀研究评述[J].混凝土,2011(1):52-56+61.
HAN Y D, ZHANG J, GAO Y. Review of sulfate attack on concrete[J]. Concrete, 2011(1): 52-56+61 (in Chinese).
[6] 王旭,黄小青,蒙坤林.国内外水泥抗硫酸盐性能研究进展[J].石家庄铁道大学学报(自然科学版),2018,31(4):96-101.
WANG X, HUANG X Q, MENG K L. Research progress on sulfate resistance cement-based materials at home and abroad[J]. Journal of Shijiazhuang Tiedao University (Natural Science Edition), 2018, 31(4): 96-101 (in Chinese).
[7] 李镜培,李林,陈浩华,等.腐蚀环境中混凝土桩基耐久性研究进展[J].哈尔滨工业大学学报,2017,49(12):1-15.
LI J P, LI L, CHEN H H, et al. Advances in concrete pile durability in corrosive environment[J]. Journal of Harbin Institute of Technology, 2017, 49(12): 1-15 (in Chinese).
[8] MEMON S A, SHAH S F A, KHUSHNOOD R A, et al. Durability of sustainable concrete subjected to elevated temperature: a review[J]. Construction and Building Materials, 2019, 199: 435-455.
[9] 汤海昌.硫酸盐侵蚀下混凝土的耐久性分析[D].南京:南京理工大学,2008.
TANG H C. The durability analysis of concrete subjected to sulfate attack[D]. Nanjing: Nanjing University of Science and Technology, 2008 (in Chinese).
[10] 左晓宝,孙伟.硫酸盐侵蚀下的混凝土损伤破坏全过程[J].硅酸盐学报,2009,37(7):1063-1067.
ZUO X B, SUN W. Full process analysis of damage and failure of concrete subjected to external sulfate attack[J]. Journal of the Chinese Ceramic Society, 2009, 37(7): 1063-1067 (in Chinese).
[11] P·库马尔·梅塔,保罗·J·M·蒙蒂罗.混凝土微观结构、性能和材料[M]. 欧阳东,译.北京:中国建筑工业出版社,2016.
MEHTA P K, MONTEIRO P J M. Concrete microstructure, properties and materials[M]. OUYANG D, Transl. Beijing: China Architecture & Building Press, 2016 (in Chinese).
[12] MEHTA P K, PIRTZ D. Magnesium oxide additive for producing self-stress in mass concrete[C]//Proceeding of 7th International Congress on the Chemistry of Cement. Paris, 1980(3): 6-9.
[13] 莫立武,邓敏.氧化镁膨胀剂的研究现状[J].膨胀剂与膨胀混凝土,2010(1):2-9.
MO L W, DENG M. Research status of magnesium oxide expander[J]. Expansive Agents & Expansive Concrete, 2010(1): 2-9 (in Chinese).
[14] 游宝坤,齐冬有.关于氧化镁膨胀剂的评述[J].膨胀剂与膨胀混凝土,2010(4):8-10.
YOU B K, QI D Y. Review on magnesium oxide expander[J]. Expansive Agents & Expansive Concrete, 2010(4): 8-10 (in Chinese).
[15] 李鹏,苗苗,马晓杰.膨胀剂对补偿收缩混凝土性能影响的研究进展[J].硅酸盐通报,2016,35(1):167-173.
LI P, MIAO M, MA X J. Effect of expansive agent on the performance of shrinkage-compensated concrete[J]. Bulletin of the Chinese Ceramic Society, 2016, 35(1): 167-173 (in Chinese).
[16] 陈昌礼,林喜华.氧化镁膨胀剂及其在混凝土中的应用[J].科学技术与工程,2020,20(28):11413-11420.
CHEN C L, LIN X H. Magnesium oxide expansion agent and its application in concrete[J]. Science Technology and Engineering, 2020, 20(28): 11413-11420 (in Chinese).
[17] 周磊,王有志,章国宁,等.纳米MgO对水泥基材料性能影响研究进展[J].混凝土与水泥制品,2019(5):13-18.
ZHOU L, WANG Y Z, ZHANG G N, et al. Research progress of the influence of nano-MgO on performance of cement-based materials[J]. China Concrete and Cement Products, 2019(5): 13-18 (in Chinese).
[18] MO L W, DENG M, TANG M S, et al. MgO expansive cement and concrete in China: past, present and future[J]. Cement and Concrete Research, 2014, 57: 1-12.
[19] 赵鹏,陈昌礼.高掺粉煤灰下MgO对水泥砂浆压蒸膨胀变形和抗压强度的影响[J].混凝土,2018(12):104-106.
ZHAO P, CHEN C L. Effect of MgO on the autoclave-treated expansion deformation and compressive strength of the cement mortar under high fly ash[J]. Concrete, 2018(12): 104-106 (in Chinese).
[20] 曹丰泽,阎培渝.活性与养护温度对氧化镁膨胀剂膨胀性能的影响[J].硅酸盐学报,2017,45(8):1088-1095.
CAO F Z, YAN P Y. Influence of chemical activity and curing temperature on expansion properties of magnesium oxide expansive agents[J]. Journal of the Chinese Ceramic Society, 2017, 45(8): 1088-1095 (in Chinese).