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工程科学与技术:2019,51(1):17-26
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带初始冻融损伤的混凝土材料受盐冻作用下性能劣化分析
(1.华北水利水电大学 水利学院, 河南 郑州 450046;2.河南省水工结构安全工程技术研究中心, 河南 郑州 450046;3.水资源高效利用与保障工程河南省协同创新中心, 河南 郑州 450046)
Analysis of Performance Deterioration of Concrete Material with Initial Freeze-thaw Damage Under Salt-freezing Condition
(1.School of Water Conservancy, North China Univ. of Water Resources and Electric Power, Zhengzhou 450046, China;2.Henan Provincial Hydraulic Structure Safety Eng. Research Center, Zhengzhou 450046, China;3.Collaborative Innovation Center of Water Resources Efficiency and Protection Eng., Zhengzhou 450046, China)
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投稿时间:2018-07-13    修订日期:2018-10-11
中文摘要: 为探明早期受冻后引起的带有初始损伤的混凝土材料在冻融循环与硫酸盐侵蚀耦合作用下力学性能的损伤演变规律,在制备混凝土试件养护期内,分别在7 d与14 d时实施冻融1次,使其产生不同程度的初始损伤,进而研究早期冻融造成的不同程度初始损伤对试件宏观性能与内部结构的影响作用。基于损伤力学理论,分别将混凝土试件的动弹性模量与抗压强度定义为损伤变量,对变量的损伤过程进行回归拟合分析,构建了由早期冻融造成的不同初始损伤试件在腐蚀受冻环境中的损伤演变方程。结果表明:两种带有不同初始损伤度的混凝土试件其各项力学性能的衰变过程受早期冻融影响均出现了“超前效应”,且该效应的出现幅度与初始损伤度有着极大联系;同时,通过对比分析混凝土超声脉冲传播速度与内部缺陷区的变化过程得知,早期冻融加速了空洞与裂缝的扩展速度,对混凝土综合性能的初始值与后期抗盐冻能力存在不利影响;动弹性模量与抗压强度损伤演变方程可作为相似损伤程度下混凝土力学性能衰减的通用公式,为相似环境下结构的服役状态评估和寿命预测提供理论依据,同时可以基于动弹性模量与抗压强度的损伤关系式对二者进行相互推导,降低了由于仪器不足等原因导致数据获取不足的局限性。
Abstract:In order to find out the damage evolution rule of the concrete with initial damage caused by early freezing under the coupling of freeze-thaw cycle and sulfate erosion, initial damage to concrete specimens by freezing and thawing them at the 7th and 14th day during the preparation of concrete specimens was carried. Based on this, different initial damage degree on macro performance and internal structure was researched. Then according to the principle of damage mechanics, the dynamic modulus of elasticity and compressive strength were defined as damage variables, by regression fitting analysis of damage process of variable, and the damage evolution equation of different initial damage specimen caused by early freeze-thaw was established in corrosion and freezing environment. The results indicated that two kinds of concrete specimens with different initial damage are affected by early freeze-thaw in the decay process of their mechanical properties and their form are "lead effect", which is closely related to the degree of initial damage. At the same time, the comparison and analysis of the change process of ultrasonic pulse propagation velocity and internal defect zone of concrete inferred that early freeze-thaw accelerates the propagation speed of cavity and crack, and the initial value of macroscopic mechanical properties of concrete and the ability of resisting salt and freezing in later stage are affected. The dynamic modulus of elasticity and the damage evolution equation of compressive strength can be used as a general formula for the attenuation of mechanical properties of concrete with similar damage degree, which can provide a theoretical basis for evaluating the service status and predicting the life of structures in similar environments. At the same time, the damage relationship between dynamic modulus of elasticity and compressive strength can be deduced from each other, which can reduce the limitation of data acquisition due to the shortage of instruments.
文章编号:201800787     中图分类号:TU528.1    文献标志码:
基金项目: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资助项目(174200510020);河南省高校科技创新团队支持计划资助项目(19IRTSTHN030);宁夏回族自治区水利科技专项资助(TYZB-ZFCG-2017-31)
作者简介:徐存东(1972-),男,教授,博士生导师,博士.研究方向:水工结构优化设计和水土环境.E-mail:xcundong@126.com
引用文本:
徐存东,程昱,王荣荣,连海东,张宏洋,白卫峰.带初始冻融损伤的混凝土材料受盐冻作用下性能劣化分析[J].工程科学与技术,2019,51(1):17-26.
XU Cundong,CHENG Yu,WANG Rongrong,LIAN Haidong,ZHANG Hongyang,BAI Weifeng.Analysis of Performance Deterioration of Concrete Material with Initial Freeze-thaw Damage Under Salt-freezing Condition[J].Advanced Engineering Sciences,2019,51(1):17-26.