| 摘要: |
| 采用pH值为30，40，50的酸液浸泡CA砂浆试件，模拟酸雨对CA砂浆的侵蚀破坏作用.对酸液浸泡的CA砂浆进行抗压强度测试、差热（DTA）分析、扫描电镜能谱（SEM EDS）分析，并用生物显微镜观察酸液中微生物的生长状况，探讨模拟酸雨对CA砂浆的侵蚀破坏机理.结果表明：酸液的长时间浸泡将导致CA砂浆试件开裂、剥落，抗压强度降低.CA砂浆经过酸液长时间浸泡后，由内到外C S H凝胶含量降低，表面出现大量CaSO4·2H2O结晶，同时酸液中含有较多的丝状真菌和酵母菌，与现场观察到的无砟轨道CA砂浆填充层生物破坏严重的现象相符合.酸液对CA砂浆的侵蚀破坏过程包括C S H凝胶的溶蚀过程、CaSO4·2H2O结晶的膨胀破坏过程和生物的腐蚀过程. |
| 关键词: CA砂浆 酸雨 C S H凝胶 盐结晶 生物腐蚀 |
| DOI：103969/j.issn1007 9629201603010 |
| 分类号: |
| 基金项目:国家杰出青年科学基金资助项目（51425804）；国家自然科学基金资助项目（51208439）；教育部博士点基金资助项目（20120184120031）；中国铁路总公司科技开发计划项目（2013G009 D） |
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| Erosion Damage Mechanism of CA Mortar in Slab Ballastless Track under Simulating Acid Rain |
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ZENG Xiaohui1, YANG Kai1, WANG Ping1, YAN Hua2, YANG Rongshan1, QU Fulin1
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1.Key Laboratory of HighSpeed Railway Engineering, Ministry of Education, Southwest Jiaotong University,Chengdu 610031, China;2.Academy of Science and Technology, China Railway Eryuan Engineering Group Co.Ltd.,Chengdu 610031, China
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| Abstract: |
| In order to clarify the erosion damage mechanism of CA mortar in simulating acid rain, specimens were immersed in acid solution with pH of 30, 40 and 50 Compressive strength tests, differential thermal analyzer, scanning electron microscope with energy dispersive spectrometer as well as biological microscope were applied to analyze the erosion damage mechanism of CA mortar in simulating acid rain. The results show that long term immersion in acid solution causes the specimens to crack, spall and decrease of compressive strength. The quantity of C S H gels in the specimen reduces from the inside out, while lots of gypsum crystals are found on the surfaces of the specimens under above mentioned conditions. Whats more, lots of filamentous fungi and yeasts are contained in long term immersing acid solution, which is consistent to the situation of seriously biological damage of CA mortar on the scene. The destruction processes of CA mortar in acid solution include C S H gel dissolution process, gypsum crystallization expanding process and biological corrosion process. |
| Key words: CA mortar acid rain C S H gel salt crystallization biological corrosion |
