【作者】 李毅强；

【导师】 熊光晶；

【作者基本信息】 汕头大学 ， 结构工程， 2005， 硕士

【摘要】 已有试验研究表明,用硅烷偶联剂溶液涂老混凝土表面,可提高新老混凝土的界面粘结强度。受其启发,本文提出以硅烷偶联剂溶液改善骨料与水泥浆界面层,从而大幅度提高大粒径骨料中等强度混凝土的耐久性的设想。作为课题研究的第一步,先着重探讨花岗岩/偶联剂/水泥砂浆界面层粘结强度的主要影响因素和作用机理。以偶联剂改性花岗岩/水泥砂浆界面层的拉拔强度和劈拉强度为指标,通过对比试验研究,探讨偶联剂溶液浓度,使用偶联剂溶液的时间和温度,还有砂浆材料配比等影响因素对界面强度的影响;结果表明,硅烷偶联剂可使花岗岩/水泥砂浆界面层强度大幅度提高;并提出了合理的偶联剂浓度、使用温度和时间。在上述试验研究结果的基础上并结合硅烷偶联剂化学和混凝土材料学,初步探讨了偶联剂在花岗岩/水泥浆界面层形成化学键的机理。其后,以硅烷偶联剂溶液浸泡大粒径花岗岩粗骨料,再拌制混凝土,结果显示混凝土的抗压强度有较大幅度的提高;为研发中等强度、耐久性良好的混凝土提供了新的技术途径。此外,本文还初步探讨了硅烷偶联剂与减缩剂共混改善新老混凝土界面层的方法。最后本文对今后的研究提出了设想与展望。更多还原

【Abstract】 Some existed experimental studies indicated that bond strength of new-to-old concrete interface could increase noticeably by coating old concrete surface with silane coupling agent. In the light of this, the idea to increase the durability of large diameter granite aggregate mid-strength concrete by modifying aggregates and cement paste interfacial layer with silane coupling agent was put forward. As the first part of the research programs, the main influencing factors of bond strength and the acting mechanism of granite/ silane coupling agent /cement paste interfacial layer was emphatically studied. Taking pull-off bonding strength and splitting tensile strength of granite/ cement paste interface modified by silane coupling agent as indexes, the influences of the solution consistency of silane coupling agent, temperature and time applied, and mix ratio of mortar materials on bond strength of granite/ cement pasteinterface were investigated through contradistinctive experimental studies. The results showed that bond strength of silane coupling agent modified granite/ cement paste interface had been greatly improved. Rational solution consistency of silane coupling agent, temperature and time applied were suggested. Based on the above experimental studies, silane coupling chemistry and concrete material, a mechanism that silane coupling agent may create chemical bonds between cement paste and granite interface was primarily put forward. Secondly, in order to develop a new technical method for producing mid-strength and durable concrete, large diameter granite aggregates were steeped in a silane coupling agent solution, followed by the mixing of the concrete. The test results showed that the compression strength of the modified concrete increased noticeably. In addition, the co-effect of silane coupling agent, shrinkage reducing admixture and fly ash on new-to-old concrete interfacial layer was primarily studied. Last, the suggestions and prospects for the future research were brought forward.更多还原