废旧胶粉掺量对改性沥青溶胀机理的影响

Microscopic characteristics of rubber modified asphalt in different rubber powder content

为了对废旧胶粉改性沥青的改性原理进行微观分析,利用热重分析、红外光谱测试和SEM电镜扫描等技术手段,从微观角度揭示了不同掺入量(20%、25%、30%、35%、40%)胶粉的70#沥青,经过高温处理后所发生的物理化学反应对改性沥青溶胀机理的影响。研究结果表明,胶粉与沥青具有较好的相容性,且能够较均匀地分布在沥青中,掺入沥青中的胶粉50%以上能够以橡胶相形式与沥青共存;高温使胶粉改性沥青发生氧化分解反应生成新的化学物质;橡胶改性沥青的溶胀性与稳定性随胶粉掺量的增加而有所增加,但高掺量的胶粉会影响改性沥青的性能,添加特殊的氧化剂可以使之显著改善。

In order to analyze the principle of modification of asphalt modified by crumb rubber powder,by means of thermogravimetric analysis,infrared spectroscopy,SEM scanning,the effect of physicochemical reactions of70#asphalt mixed with different quantities(20%,25%,30%,35%,40%)on the mechanism of the swelling of modified asphalt after high temperature treatment was revealed from microscopic angle.Results show that:Rubber powder have good compatibility with asphalt and can be distributed evenly in asphalt.In addition to a small part of the rubber powder that has reacted chemically,most of the rubber,more than50%of the rubber powder can exist as its original form;High temperature causes the rubber powder asphalt modified to generate new chemical matter by oxidation decomposition reaction.The swelling property and stability of modified asphalt will increase with the increase of the amount of rubber powder,but high content of the powder will affect the performance of modified asphalt,which can be improved remarkably by adding special oxidant.