TLA掺量对湖沥青改性沥青高、低温性能的影响

Influence of TLA Dosage on High Temperature and Low Temperature Properties of Lake Asphalt Modified Asphalt

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。

The effect of different TLA content on high temperature and low temperature properties of lake asphalt modified asphalt is studied in this paper. The TLA contents of 15%, 25% and 35% of the lake asphalt modified asphalt were tested through dynamic shear rheology, creep and creep recovery experiment to evaluate itSs high-temperature property. And ductility test and BBR test were also applied to study it＇s low- temperature property. The results show that the rut factor and fail temperature of unaged asphalt and RTFO aging asphalt are improved greatly. The PG classification has improved by at least a high-temperature level when the TLA content changes from 15% to 35%. With the increasing content of TLA, zero shear viscosity of Lake asphalt modified asphalt increases gradually. And the high-temperature property of lake asphalt modified asphalt has improved evidently. However, the ductility values and creep rate of lake asphalt modified asphalt are decreased, while the creep stiffness increases continually. It shows that the addition of TLA is detrimental to the low-temperature property. Considering the high and low temperature of TLA is recommended 25 %-35%.