摘要
针对西北寒旱灌区混凝土结构在侵蚀冻融复合作用下的破坏问题,采用快速冻融试验,分别研究了水、3%NaCl、5%Na2SO4作用下混凝土试件质量损失、抗压强度及相对动弹性模量的变化规律,采用损伤度来描述混凝土的损伤情况,分析了盐冻作用机理,建立了相对动弹性模量和抗压强度相关联的力学衰减模型,并利用试验数据对其进行验证分析。结果表明:混凝土试件在不同的冻融介质作用下存在不同程度的损伤,在3%NaCl溶液中冻融试件损伤度最高达到清水冻融的5倍以上,75次冻融之前5%Na2SO4溶液对混凝土损伤有抑制作用,冻融环境下三种介质对混凝土损伤度大小排序为3%NaCl>5%Na2SO4>水;混凝土相对剩余抗压强度和相对动弹性模量相关性良好,服役中的混凝土结构可以通过测定相对动弹性模量评估抗压强度。相关研究可为寒旱区混凝土结构维护和病害预防提供参考。
In view of the damage of concrete structure under the combined action of erosion and freeze?thaw in northwest China cold and arid irrigation area,rapid freeze?thaw test was used to study the variation of mass loss,compressive strength and relative dynamic modulus of elas?ticity of concrete specimens under the action of water,3%NaCl and 5%Na2SO4 respectively.Damage degree was used to describe the dam?age of concrete,and the mechanism of salt?freeze was analyzed.The mechanical attenuation model related to the relative dynamic elastic mod?ulus and compressive strength was established and tested by experimental data.The results show that the concrete specimens have different degrees of damage under different freeze?thaw media.The damage degree of freeze?thaw specimens in 3%NaCl solution reaches 5 times of that in clear water.Before 75 freeze?thaw cycles,5%Na2SO4 solution restrains the damage of concrete.In freeze?thaw environment,the dam?age degree of three kinds of media to concrete ranks as follows:3%NaCl>5%Na2SO4>water;the relative residual compressive strength of concrete has good correlation with relative dynamic elastic modulus,and the concrete structure in service can evaluate the compressive strength by measuring relative dynamic elastic modulus.Relevant research can provide reference for concrete structure maintenance and dis?ease prevention in cold and arid areas.
作者
徐存东
李振
朱兴林
姚志鹏
王铭岩
张鹏
XU Cundong;LI Zhen;ZHU Xinglin;YAO Zhipeng;WANG Mingyan;ZHANG Peng(School of Water Conservancy,North China University of Water Resources and Electric Power,Zhengzhou 450046,China;Henan Provincial Collaborative Innovation Center of Water Resources Efficiency and Protection Engineering,Zhengzhou 450046,China;Henan Provincial Hydraulic Structure Safety Engineering Research Center,Zhengzhou 450046,China)
出处
《人民黄河》
CAS
北大核心
2019年第9期132-136,共5页
Yellow River
基金
国家自然科学基金资助项目(51579102,31360204)
河南省科技厅科技创新人才支持计划项目(174200510020)
河南省高校科技创新团队支持计划项目(19IRTSTHN030)
宁夏回族自治区水利科技专项(TYZB-ZFCG-2017-31)
关键词
盐冻
冻融介质
侵蚀破坏
损伤程度
衰减模型
混凝土
西北寒旱灌区
salt-freeze
freeze-thaw media
erosion damage
damage degree
attenuation model
concrete
northwest China cold and arid irrigation area
