硫酸盐-干湿循环下UHPC耐久性及本构模型研究  

Sulfate Resistance of Ultra High Performance Concrete under Wet and Dry Cycling

作　　者：赵靖伟[1] 杨顺 ZHAO Jingwei;YANG Shun(Northwest Engineering Corporation Limited,Xi’an 710065,China;College of Water Conservanly and Hydrpower,Xi’an University of Technology,Xi’an 710048,China)

机构地区：[1]中国电建集团西北勘测设计研究院有限公司,西安710065 [2]西安理工大学水利水电学院,西安710048

出　　处：《西安工业大学学报》2024年第5期566-574,共9页Journal of Xi’an Technological University

基　　金：国家自然科学基金(52279139)。

摘　　要：为研究干湿循环作用下超高性能混凝土(UHPC)经不同浓度硫酸盐溶液侵蚀后的单轴压缩损伤特征及应力-应变行为,从而有效评价不同侵蚀程度下UHPC的力学性能,对四组UHPC试件进行了硫酸盐和干湿循环耦合试验,证明UHPC试件的质量及立方体抗压强度随干湿循环周期发展呈先上升后下降。利用声发射(AE)系统研究了单轴压缩模式下的损伤演化,将UHPC的单轴压缩损伤过程分为了四个阶段,结果表明,应力-应变曲线的阶段性发展与声发射特征参数的趋势关联紧密,UHPC的损伤演化与声发射振幅(AEA)联系紧密。最后根据应力-应变数据建立了侵蚀损伤本构模型,该模型能够准确地反应UHPC经硫酸盐和干湿循环耦合作用后的单轴压缩损伤演化规律,可为盐碱地区混凝土结构的设计和安全运行提供参考。In order to study the uniaxial compression damage characteristics and stress strain behavior of ultra high performance concrete(UHPC)after being attacked by sulfate solutions of different concentrations under the action of dry wet cycles,and thus effectively evaluate the mechanical properties of UHPC under different erosion degrees,four groups of UHPC samples were subjected to the coupling test of sulfate and dry wet cycles.The results show that the change of mass and compressive strength increases first and then decreases.Acoustic emission(AE)system was used to study the damage evolution under uniaxial compression mode,and the uniaxial compression damage process of UHPC was divided into four stages.The results showed that the stress strain curve and acoustic emission characteristic parameters showed a strong correlation,and the damage evolution of UHPC was closely related to the AEA in the process of stage change.Finally,based on the stress strain data,a constitutive model of erosion damage was established,which can accurately reflect the uniaxial compression damage evolution of UHPC under the coupling action of sulfate and dry wet cycles,and can provide references for the design and safe operation of concrete structures in saline alkali areas.

关 键 词：硫酸盐-干湿循环 超高性能混凝土 单轴压缩 声发射 

分 类 号：TU599[建筑科学—建筑技术科学]