混凝土在醋酸钙镁除冰液作用下的冻融破坏机理  

The mechanism of freeze-thaw damage in concrete under a calcium magnesium acetate deicer

作　　者：马好霞 余红发 李创 白康 MA Haoxia;YU Hongfa;LI Chuang;BAI Kang(College of Civil Aviation, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China;College of Economics and Management, Nanjing Vocational University of Industry Technology, Nanjing 210046, China;Beijing Ancient City Real Estate Development Co., Ltd, Beijing 100124, China;Ji′nan City Construction Design and Research Institute Co., Ltd, Ji′nan 250101, China)

机构地区：[1]南京航空航天大学民航学院,江苏南京210016 [2]南京工业职业技术大学经济管理学院,江苏南京210046 [3]北京古城房地产开发有限公司,北京100124 [4]济南市城建设计研究院有限责任公司,山东济南250101

出　　处：《哈尔滨工程大学学报》2022年第2期304-310,共7页Journal of Harbin Engineering University

基　　金：江苏省博士后基金/A类项目(2021K003A);南京市建设行业科技计划项目(Ks2126);江苏省生产力学会2020年开放课题(JSSCL2020B002);国家重点基础研究发展计划(2015CB655100);国家自然科学基金项目(51178221,51678304).

摘　　要：为进一步研究冻融过程中醋酸钙镁除冰液对混凝土的冻融破坏机理,本文配置不同质量浓度的醋酸钙镁除冰液,进行其在低温下的结冰压力实验;制备硅酸盐水泥混凝土和抗硫酸盐水泥混凝土,进行其在水冻和醋酸钙镁除冰液盐冻环境下的冻融实验;同时对冻后的混凝土表层物相进行X射线衍射实验,使用扫描电子显微镜实验分析混凝土内部微观结构变化。实验结果表明:水的结冰压力稳定值最高,醋酸钙镁除冰液的I_(p)值随着除冰液浓度的升高而降低。混凝土在水中和醋酸钙镁除冰液中的冻融损伤主要是由内部的冻融微裂纹和外部剥落引起。20%粉煤灰掺量下,普通硅酸盐水泥混凝土的抗冻性明显优于抗硫酸盐水泥混凝土;醋酸钙镁除冰液对混凝土存在冻融破坏和化学腐蚀破坏作用,但短期的冻融循环过程中醋酸钙镁除冰液对混凝土的破坏现象依旧比水轻。Calcium magnesium acetate(CMA)solutions of different concentrations were prepared to test ice-formation pressures(I)under low temperatures to study the mechanism of freeze-thaw damage in concrete under CMA-type deicers.Portland cement concrete and sulfate-resistant cement concrete were prepared,and freeze-thaw experiments were carried out with freezing water and CMA deicers simultaneously.X-ray diffraction was conducted on the surfaces of frozen concrete,and scanning electron microscopy was used to analyze changes in the internal microstructure of the concrete.The I_(p) of water was the highest among all solutions,and the I_(p) of CMA deicers decreased with increasing concentration.The freeze-thaw failure of concrete in water and CMA deicers was mainly caused by internal micro-cracks and external mortar spalling.The frost resistance of Portland cement was significantly higher than that of sulfate cement with 20%fly ash.CMA deicers induced freeze-thaw and corrosion damage to concrete,but the damage was less than that of water in short-term freeze-thaw cycles.

关 键 词：混凝土 醋酸钙镁除冰液 氯化钠除冰液 结冰压 冻融破坏 微观分析 化学腐蚀 破坏机理 

分 类 号：TU528[建筑科学—建筑技术科学]