碳纳米管/SBS复合改性沥青低温蠕变性能

为探究碳纳米管/SBS复合改性沥青的低温蠕变性能,采用弯曲梁流变试验对复合改性沥青低温性能进行评价,探究老化对低温性能的影响,采用Burgers模型分析其不同状态下的粘弹性参数,采用综合柔量评价了复合改性沥青的低温抗裂性能。结果表明,较低掺量的碳纳米管可以改善SBS改性沥青的低温蠕变性能,但其掺量较高(>0.9%)时整体低温性能又会受到影响;老化使得复合改性沥青的低温性能变差,并且老化程度越深,低温性能下降越明显;在SBS改性沥青中掺入碳纳米管会降低改性沥青的应力松弛能力,使其更加趋于弹性体,对改性沥青的低温性能产生不利影响。从低温蠕变性能角度评估,碳纳米管的最佳掺量范围约为0.6%~0.9%。

青藏高原地区高标号沥青及改性沥青高低温性能试验研究

基于青藏高原地区特殊地形地貌、气候环境条件,旨在研究不同温度、频率等因素作用对不同高标号沥青及改性沥青的性能影响,通过DSR试验得到高温抗车辙因子和疲劳因子,以评价高标号沥青的高温稳定性和抗疲劳性能;通过BBR试验得到蠕变劲度和蠕变速率,以评价高标号沥青的低温抗开裂性能。

纳米SiO_2改性沥青老化性能及黏温特性研究

将掺量为5%的纳米SiO_2加入普通70#石油沥青中,通过高速剪切制取了纳米SiO_2改性沥青,并采用旋转薄膜烘箱对其进行了不同时间的老化,对不同老化时间后的纳米SiO_2改性沥青性能进行了测定;采用旋转黏度仪对不同温度下的纳米SiO_2改性沥青的旋转黏度进行了测定,并同普通70#沥青进行了对比,对纳米SiO_2改性沥青的黏温特性进行了研究;通过弯曲梁蠕变试验对纳米SiO_2改性沥青的低温蠕变特性进行了试验。结果表明:纳米SiO_2的掺加改善了沥青的抗老化性能;纳米SiO_2改性沥青在常温下的黏度明显高于普通石油沥青,而随着温度的升高,这一差距逐渐缩小;纳米SiO_2改性沥青混合料的施工温度高于普通石油沥青混合料,且当纳米SiO_2掺量为5%时,其最佳拌和温度为168~174℃,最佳压实温度为157~162℃;纳米SiO_2改性沥青的低温性能略逊于普通沥青。

The Correlation between Density and Low-Temperature Creep Property of Asphalt

The density of asphalt was measured with the pycnometer and densitometer. Creep properties of the asphalt were investigated with the bending beam rheometer at temperatures ranging from 0 ~C to -36 ~C. The asphalt density data used to correlate with the creep properties were calculated from the regression equation of density and temperature. The asphalt sample used to determine the creep property was aged by the standard RTFOT test and the PAV test. The test results showed that the asphalt density had a linear relationship with temperature changes. The logarithm of the creep stiffness and the slope of the logarithm of the stiffness at 60 seconds all demonstrated a linear relationship with the density, and the regression coefficient of these data was around 0.99. The creep stiffness and the slope of the creep stiffness can be calculated from the asphalt density at the same temperature.