加固用丁苯混凝土长期黏结性能及机理研究  

Study on long-time interfacial bonding performance and mechanism of SBR modified cement-based concrete strengthened in RC structure

作　　者：农金龙[1] 易伟建[1] 黄政宇[1] 何伟[1] 

机构地区：[1]湖南大学土木工程学院,湖南长沙410082

出　　处：《建筑结构学报》2012年第12期112-120,共9页Journal of Building Structures

基　　金：国家自然科学基金项目(51178175)

摘　　要：研究了加固用丁苯乳液水泥基混凝土/砂浆/浆体与既有混凝土的长期黏结性能,对此类聚合物水泥基材料长期黏结性能作用机理进行试验研究。结果表明,丁苯浆体斜剪、直剪、受折、轴向拉伸及丁苯混凝土劈裂强度性能优越,丁苯砂浆的长期水泥水化程度较高和其特有的有益的水泥水化变化规律相关,丁苯砂浆受热和干缩变形规律不损害其长期黏结性能,有些变形甚至对其长期黏结性能有益,电镜照片显示其界面黏结效果良好,与其宏观良好的长期黏结性能相一致,诠释和推证了其长期黏结机理。研究成果有助于理解此类聚合物水泥基材料的中长期黏结性能,并对实际工程应用中正确选用界面黏结材料及评价黏结效果提供参考。The long-time interfacial bonding performance and mechanism of Styrene-Butadiene-Rubber（SBR） latex modified cement-based concrete/mortar/paste strengthened in RC structure were studied by some tests in this paper.The findings indicate that Styrene-Butadiene-Rubber（SBR） latex modified cement-based mortar has a good long-time interfacial bonding performance.The slanting shear,flexural,direct shear and direct axial tension tests were conducted to evaluate SBR latex modified cement-based paste resistance to the breaking stress in strengthened RC structure.At the same time,splitting strength of SBR latex modified cement-based concrete is high.Semi-adiabatic exothermal hydration test was used to study the hydration interaction between SBR and cement in the mortar.The dry shrinkage and heating deformation tests were utilized to research characteristics of SBR latex modified cement-based mortar encountered with temperature and humidity change.Scanning electron microscope（SEM） was employed to read the microscopic structure of transition region in SBR latex modified cement-based mortar strengthened in RC structure.Long-time interfacial bonding mechanism was thoroughly discussed to based on data of these associated tests.

关 键 词：丁苯混凝土 砂浆 浆体 受热变形 干缩变形 试验研究 长期黏结性能 长期黏结机理 

分 类 号：TU528.41[建筑科学—建筑技术科学] TU502