印刷电路板改性沥青流变特性和微观结构的研究

The asphalt modified with different printed circuit boards(PCBs) content(0, 5%, 10%, and 15%) was prepared in this study. The general properties, rheological properties, temperature sensitivity, fatigue resistance, and morphology of the PCBs modified asphalt were investigated by conventional tests, the Brookfield viscometry tests, the dynamic shear rheometer(DSR) tests, the bending beam rheometer(BBR) tests, and the fluorescence microscopy tests. And the influence of PCBs content on the above-mentioned properties was analyzed systematically. The results showed that the addition of PCBs could improve the high temperature performance, the low temperature performance, and the temperature sensitivity property of the modified asphalt, while compromising with the fatigue resistance of the modified asphalt. With the increase of PCBs content, the modified asphalt could have better softening points, viscosity, failure temperature, and temperature sensitivity, while its low temperature performance and fatigue resistance became worse to different degree. And the particle size of PCBs became bigger and non-uniform with an increasing PCBs content. According to the above-mentioned properties, the optimum PCBs content was specified at less than 10% in the modified asphalt system.     

TLA掺量对湖沥青改性沥青高、低温性能的影响

为研究不同TLA掺量对湖沥青改性沥青高温、低温性能的影响,对TLA掺量为15%、25%、35%的湖沥青改性沥青分别采用动态剪切流变试验、蠕变及蠕变恢复试验来研究其高温性能;采用延度试验和BBR试验研究其低温性能。试验结果表明:老化前的湖沥青改性沥青以及RTFO老化后的湖沥青改性沥青的车辙因子G*/Sinδ值和破坏温度(fail temperature)都得到较大的提高,TLA掺量为35%比掺量为15%的湖沥青改性沥青的PG分级至少提高一个高温等级;随着TLA掺量的增加,湖沥青改性沥青的零剪切粘度逐渐变大,高温性能得到显著改善;但是湖沥青改性沥青的延度值和蠕变速率m却在减小,蠕变劲度s值在不断增大,表明TLA的加入对其低温性能是不利的。综合考虑高温、低温性能,建议TLA的合理掺量控制在25%~35%之间。     

RAP掺量对泡沫温拌再生沥青混合料路用性能的影响

为探求RAP掺量对泡沫温拌沥青混合料路用性能的影响,以AC-20型泡沫温拌再生沥青混合料进行配合比设计,成型RAP掺量分别为20%、30%、50%、60%和80%的马歇尔试件。分别利用车辙试验、低温小梁弯曲试验、冻融劈裂试验来评价其高温性能、低温性能和抗水损害性能。试验结果表明:随着RAP掺量的增加,泡沫温拌再生沥青混合料的高温性能不断提高,而其低温性能和抗水损害性能不断变差,当RAP掺量大于50%时,泡沫温拌再生沥青混合料的低温性能和抗水损害性能已不再满足规范要求。综合考虑混合料的路用性能,确定RAP在泡沫温拌再生沥青混合料中的最佳掺量为40%,供生产及控制时参考。