偶联剂改善沥青混凝土性能及油石界面试验研究

试验探讨了偶联剂作为油石界面改性剂对沥青混凝土性能改善的可能性.试验发现,偶联剂无论对酸性花岗岩石料还是中性玄武岩石料的沥青混凝土性能都具有明显的改善作用.添加偶联剂的沥青,对石料的黏附等级达到5级,而改性前的沥青与花岗岩和玄武岩的黏附等级仅为2级和3级;马歇尔稳定度比基质沥青混凝土提高10%～20%,马歇尔模数提高约6%,残留马歇尔稳定度提高18%～28%,3次冻融循环后的劈裂强度比相对于基质沥青混凝土提高25%～33%.红外光谱分析证实,偶联剂在花岗岩和玄武岩石料表面均形成一层偶联层.消耗石料表面残留水分、形成偶联化层和提高沥青在石料表面的润湿速度是硅烷偶联剂改善油石界面的根本原因.

Experimental research on modification of asphalt concrete performance and asphalt-aggregate interface by coupling agent

Asphalt aggregate interface is one of the crucial factors in asphalt concrete. A coupling agent applied as a modifier for asphalt aggregate interface is inves tigated in this paper. Experiments prove that the coupling agent can effectively improve the performances of asphalt concrete, no matter whether the aggregate is acidic granite or neutral basalt. The cohesiveness between asphalt and granit e or basalt can achieve grade 5. In contrast, it is only grade 2 and 3 if the as phalt is not modified by the coupling agent. Marshall stability, Marshall modu les and residual Marshall stability of asphalt concrete is increased by 10%-20% , about 6% and 18%-28% respectively. The retained tensile strength ratio after three freezing and thawing cycles can be increased by 25%-33%. Infrare d spectrograph analysis shows that the coupling agent reacts with the surface of aggregates. The improvement of the modified asphalt aggregate interface is ma inly due to the depletion of retained water in pores of aggregate, formation of coupling layer and speeding up of asphalt soakage by the coupling agent.