有机飞机除冰液作用下普通混凝土的抗冻性微观机理分析

结合现有的冻融破坏理论，研究了以乙二醇为主要成份的飞机除冰液作用下普通混凝土冻融损伤失效规律与特点.采用X射线衍射仪、扫描电子显微镜和X射线能量色散谱仪，进行试件冻融后的物相组成、微观结构变化以及微区元素分析.实验结果表明：低质量分数乙二醇对混凝土抗冻剥蚀性比水严重，高质量分数乙二醇对混凝土的冻融破坏比水轻微.飞机除冰液质量分数越低，对混凝土的冻融破坏作用越严重；低质量分数乙二醇对普通混凝土的冻融破坏以表面剥落破坏为主，质量损失首先达到破坏标准.高质量分数乙二醇对普通混凝土的冻融破坏以相对动弹性模量首先达到破坏标准，主要表现为端部的严重冻疏.在乙二醇飞机除冰液冻融过程中普通混凝土内没有新物质生成，水化硅酸钙凝胶与氢氧化钙晶体未发生变化.普通混凝土在乙二醇飞机除冰液中的冻融破坏机理与水中一样，以结冰压破坏为主.
On the basis of freeze-thaw damage theories，the freeze-thraw damage pattern and feature of ordinary Portland concrete (OPC) were studied under the aircraft de-icer with ethylene glycol. The micro-phase compositions of specimens were analyzed by X-ray diffractometer，microstructure was observed by scanning electron microscopy and Micro area element was analyzed by energy dispersion X-ray. The main results were remarked as follows: The frost resistance of concrete under the action of lower concentration of EG was more serious than that of water，while the freezing and thawing damage in higher concentration of ethylene glycol was slightly lower than that of water. The lower concentration of aircraft deicing fluid results in more serious damage to the concrete. The freeze-thaw damage of OPC with low concentration of ethylene glycol was mainly the surface spalling failure，and the mass loss reached the standard of failure firstly. However，when immersed in high concentration of ethylene glycol，the freeze-thaw damage of OPC was that the relative dynamic elastic modulus first came up to the failure stand，which was mainly embodied in severe spalling at the ends. In a whole，the freezing and thawing damage was a physical damage mechanism. No new substances were formed during the freezing and thawing experiment in EG. The hydrated calcium silicate gel and crystal of calcium hydroxide were not changed in cement. The freezing thawing damage mechanism of OPC in EG solution was the same as that in water，which was mainly dominated by the freezing pressure.