【作者】 李屹立；

【导师】 熊光晶； 陆小华；

【作者基本信息】 汕头大学 ， 结构工程， 2006， 硕士

【摘要】 宏观力学性能实验研究表明，经硅烷偶联剂(SCA)改性的花岗岩／水泥浆界面层粘结强度显著优于既有的界面层改性方法的粘结强度，故用SCA处理花岗岩骨料很可能是一种大幅度提高量大面广的普通混凝土强度和耐久性的有效方法。由于这是一种全新的改善混凝土中骨料和水泥浆体界面层性能的方法，有必要对其作用机理作深入的探讨。 笔者首先通过试验研究，探讨改性反应温度和时间对花岗岩／SCA／水泥浆界面层劈拉强度的影响，又用分光光度计和接触角测定仪分析SCA与花岗岩表面的结合形式，然后又利用傅里叶变换红外光谱(FTIR)和X射线光电子能谱(XPS)证实了SCA与花岗岩表面即使在常温下也可以产生化学键结合。综合分析试验结果表明，SCA与花岗岩表面有物理吸附、化学吸附和化学键三种牢固程度不同的结合形式，且随着反应温度和时间的提高，骨料表面化学吸附和化学键结合的SCA量增多。然而，宏观试验结果却表明，常温下反应时间较短时的效果最好。由此，笔者从物理和化学方面对花岗岩／SCA／水泥浆界面层的形成进行了初步探讨，提出了界面层微细观结构的改善和新的硅氧硅键的形成及其对粘结强度的提高的机理。最后本文对今后的研究提出了设想与展望。更多还原

【Abstract】 Several mechanical experimental researches have indicated that the bond strength of granite/silane coupling agent (SCA)/cement paste interfaces is much higher than that of the granite /cement interfaces obtained using existing granite surface modification methods. Hence SCA surface modification is likely to be a superior means to improve the strengths and durability of the billions of tons of concrete used worldwide. This is a new method to improve the bond strength between aggregates and cement paste. It is hence necessary to investigate the bond mechanisms.The influence of SCA/aggregates reaction time and temperature was investigated through an experimental study. Spectrophotometry and contact angle measurements were used to investigate the formation of the granite/SCA interfaces. Fourier transform infrared spectrometer (FTIR) and X-ray Photoelectron Spectroscopy (XPS) experiments had revealed that strong chemical bonds (even in room temperature) have formed on the modified surfaces of the granite. The results of all the experiments showed that physical adsorption, chemical adsorption and chemical bonds were formed between the SCA and the aggregates. The longer time and higher temperature at reaction, the more chemical adsorption and chemical bonds are formed. However, mechanical experiments indicated that higher aggregate/cements bond strengths were obtained at room temperation with short reaction time. The author investigated the formation of the granite/SCA/cement paste interfacial layers with respect to physical and chemical considerations. A mechanism describing the formation of the modified interfacial transition zone and its improvements to the aggregates/cement paste bond strength was proposed. Finally, propositions of future research were brought forward.更多还原