【作者】 冯玉龙；

【导师】 熊光晶； 陆小华；

【作者基本信息】 汕头大学 ， 结构工程， 2007， 硕士

【摘要】 力学实验表明，硅烷偶联剂（SCA）可显著提高花岗岩／水泥浆界面层粘结强度，为了给SCA改性混凝土的工程应用提供技术支持，本文采用三因素五水平正交设计方法，研究了SCA浓度、醇水比、浸泡时间，以及各因素之间交互作用对SCA改性花岗岩骨料混凝土立方体抗压强度的影响，确定了最优的配方。结果表明：醇水比4：1、浸泡时间1min、SCA浓度0.5％～1％时改性效果最佳。红外光谱（FTIR）和X射线能谱（XPS）实验已经证实SCA与花岗岩之间形成了较牢固的结合，但花岗岩表面SCA与水泥浆作用机理尚不清楚，为深入探讨SCA显著提高花岗岩／水泥浆界面粘结强度的机理，本文设计了一种新的实验方法，让水泥水化物直接在骨料表面沉积成晶，并用扫描电镜（SEM）观察表面结晶水泥水化物的形貌，用X射线衍射仪（XRD）观测表面结晶产物中Ca（OH）₂的含量和取向性，用XPS观测表面结晶水泥水化物各元素结合能的变化情况。微观实验结果表明：SCA改性对骨料—水泥浆界面过渡区的形成有重要影响；SCA改性前后花岗岩表面结晶水泥水化产物各元素结合能没有发生变化。更多还原

【Abstract】 Mechanical testing shows that interfacial bond strength between SCA-soaked granite andcement paste is extremely improved. In order to provide technology support for the practicalapplication of SCA modified concrete, a three-factor-five-level orthogonal design was set toinvestigate the influence of SCA concentration、ratio of ethanol / water、dipping time and theinteractions among the factors on concrete compressive strength with SCA modified graniteaggregates. The result shows that a combination of ethanol / water 4:1, dipping 1 min and SCAconcentration of 0.5%～1% yields an optimum solution.FTIR and XPS experiment has already identified that strong bonds can be formed betweenSCA and granite surface, but the action mechanism between SCA modified granite surface andcement pastes is still unknown. For deeply investigating the modifying mechanism of theinterfacial bond strength between SCA-soaked granite and cement paste, a new experimentalmethod to simulate crystallization of cement hydration products on aggregates surface wasdeveloped. The crystal morphology of the cement hydration products is observed by SEM; thecontents and orientation of Ca（OH）₂ on aggregate surface are observed by XRD; the chemicalshifts of each crystal cement hydration products element on aggregate surface by XPS. The resultshows that the SCA modification has an important influence on the formation ofaggregates-cement paste interfacial transition zone; no chemical shifts of crystal cementhydration products element is produced.更多还原