纳观尺度沥青相态力学特性老化行为

选取原样、短期老化和长期老化的基质沥青与SBS改性沥青为研究对象, 利用原子力显微技术的定量纳米力学(QNM)性质功能模块测试了沥青纳观相态的力学性质; 利用Nano Scope Analysis软件对沥青相态力学图像进行量化分析, 重点分析了相态模量和黏附力这2个指标; 采用细观力学领域中的Halpin-Tsai模型研究了沥青多相态力学性质的复合行为, 并探究了纳观尺度沥青相态力学特性的老化行为。分析结果表明: 基质沥青中蜂形相态和基质相态的纳观模量分别集中在600.0和18.3 MPa, 纳观黏附力分别集中在10.3和18.6 nN; SBS改性沥青中蜂形相态和基质相态的纳观模量分别集中在899和35 MPa, 纳观黏附力分别集中在30.2和38.4 nN; 对于基质沥青, 原样、短期老化和长期老化沥青的复合模量分别为111、138和187 MPa, 复合黏附力分别为16.7、14.3和4.2 nN; 对于SBS改性沥青, 原样、短期老化和长期老化沥青的复合模量分别为158、313和547 MPa, 复合黏附力分别为32.2、35.0和15.8 nN; 沥青纳观相态结构中, 蜂形相态属于高模量、低黏附力相态, 而基质相态属于低模量、高黏附力相态; SBS改性沥青的相态模量与黏附力显著高于基质沥青; 随着老化程度的增加, 沥青相态的力学性质发生变化, 且不同相态的老化行为存在显著差异; 采用QNM技术可有效辨别纳观尺度沥青相态的力学特性, Halpin-Tsai模型可用于量化沥青相态力学性质的复合行为。 

Aging behaviors of nanoscale mechanical properties of asphalt phases

The original, short-term aging and long-term aging base asphalts and SBS modified asphalts were selected as the research objects, the atomic force microscopy with quantitative nano mechanical(QNM) property function mode was used to measure the mechanical properties of the asphalts in nanoscale phases. The software Nano Scope Analysis was applied to quantitatively analyze the mechanical images of asphalt phases. Two indicators such as the phase modulus and adhesion were mostly analyzed. The Halpin-Tsai model in the field of mesoscale mechanics was used to study the composite behaviors of mechanical properties of the asphalts in multiple phases, and the aging behaviors of mechanical properties of the asphalt phases in nanoscale were investigated. Analysis result shows that the nanoscale moduli of bee phase and base phase in the base asphalt are concentrated at 600.0 and 18.3 MPa, respectively, and the corresponding nanoscale adhesion are concentrated at 10.3 and 18.6 nN, respectively. The nanoscale moduli of bee phase and base phase in the SBS modified asphalt are concentrated at 899 and 35 MPa, respectively, and the corresponding nanoscale adhesion are concentrated at 30.2 and 38.4 nN, respectively. For the base asphalt, the composite moduli of original, short-term aging and long-term aging asphalts are 111, 138, and 187 MPa, respectively, and the composite adhesion are 16.7, 14.3, and 4.2 nN, respectively. For the SBS modified asphalt, the composite moduli of original, short-term aging and long-term aging asphalts are 158, 313, and 547 MPa, respectively, and the composite adhesion are 32.2, 35.0, and 15.8 nN, respectively. In the nanoscale phase structure of asphalt, the bee phase has a high modulus and a low adhesion, while the base phase has a low modulus and a high adhesion. The phase modulus and adhesion of SBS modified asphalt are significantly higher than that of base asphalt. As the aging degree increases, the mechanical properties of asphalt phases change, and the aging behaviors of different phases vary significantly. Therefore, the QNM technology can effectively identify the nanoscale mechanical properties of asphalt phases, and the Halpin-Tsai model can be used to quantify the composite behaviors of mechanical properties of asphalt phases.