盐类结晶破坏环境下隧道衬砌混凝土适宜含气量研究  

Study on Appropriate Air Content of Tunnel Lining Concrete in the Environment of Salt Crystallization Damage

作　　者：黄法礼 李化建 陶建强 王振 易忠来 谢永江 HUANG Fali;LI Huajian;TAO Jianqiang;WANG Zhen;YI Zhonglai;XieYongjiang(Railway Engineering Research Institute,China Academy of Railway Sciences Corporation limited,Beijing 100081,China;State Key Laboratory for Track Technology of High-speed Railway,Beijing 100081,China;College of Materials Science and Engineering,Chongqing University,Chongqing 400045,China)

机构地区：[1]中国铁道科学研究院集团有限公司铁道建筑研究所,北京100081 [2]高速铁路轨道技术国家重点实验室,北京100081 [3]重庆大学材料科学与工程学院,重庆400045

出　　处：《铁道建筑》2019年第12期74-78,共5页Railway Engineering

基　　金：国家自然科学基金(51578545);中国铁路总公司科技研究开发计划(N2018G029)

摘　　要：为提高盐类结晶破坏环境下隧道衬砌混凝土结构耐久性,以隧道衬砌混凝土为研究对象,系统研究了含气量对混凝土工作性能、力学强度、孔结构、气泡参数和抗硫酸盐结晶破坏性能的影响。结果表明:含气量对混凝土力学性能的影响存在临界值,当混凝土含气量小于4.6%时含气量对混凝土抗压强度影响较小,当混凝土含气量大于4.6%时随着含气量的增大混凝土强度降低幅度较大;硫酸盐干湿循环条件下,随着干湿循环次数的增加混凝土强度略微增大,干湿循环次数达到90次之后混凝土强度开始明显降低;随着含气量增大,混凝土内部无害孔和少害孔比例明显减少,有害孔和多害孔的比例显著增大;新拌混凝土含气量与硬化混凝土含气量、气泡参数之间均具有良好相关性,控制新拌混凝土含气量大于4%时即可满足盐类结晶破坏环境下对混凝土气泡参数的要求;混凝土抗硫酸盐侵蚀性能随含气量增大呈现先增大后减小的趋势。In order to improve the durability of tunnel lining concrete structure in the environment of salt crystallization damage,the influence of air content on the working performance,mechanical strength,pore structure,bubble parameters and sulfate crystallization damage resistance of concrete was studied by taking tunnel lining concrete as the research object.The results show that there is a critical value for the influence of air content on the mechanical properties of concrete.The influence of air content on the compressive strength of concrete is small when the air content of concrete is less than 4.6%,and the strength of concrete decreases greatly with the increase of air content when the air content of concrete is more than 4.6%.The strength of concrete increases slightly with the increase of drying and wetting cycles,and the strength of concrete begins to decrease obviously after the drying and wetting cycles reaches 90 under the condition of sulfate drying and wetting cycles.The proportion of harmless holes and less harmful holes in concrete decreases,while the proportion of harmful holes and more harmful holes increases with the increase of air content.There is a good correlation between the air content of fresh concrete and the air content and the bubble parameters of hardened concrete.When the air content of fresh concrete is more than 4%,it can meet the requirements of bubble parameters of concrete in the environment of salt crystallization damage.The sulfate resistance of concrete increases first and then decreases with the increase of air content.

关 键 词：隧道衬砌 混凝土 试验研究 含气量 盐类结晶破坏 耐久性 孔结构 强度 气泡参数 

分 类 号：TU528[建筑科学—建筑技术科学]