热老化作用下橡胶改性沥青的低温流变性能

为探究老化作用下橡胶改性沥青(AER)及其复合改性沥青(AER/SBS)的低温流变性能,借助常规性能、低温弯曲试验和Burgers模型,研究了在不同老化状态、不同橡胶粉掺量下AER改性沥青及其复合改性沥青的低温流变特性,同时借助红外光谱(FTIR)方法定量分析老化对AER改性沥青官能团的影响,并将其官能团指数和低温指标...

Low Temperature Rheological Performance Analysis of Rubber Modified Asphalt under Heat Aging Process

In order to explore the low temperature rheological properties of rubber modified asphalt (namely the activated twin-screw extruded rubber (AER) powder modified asphalt) and AER/SBS (styrene-butadiene styrene) composite modified asphalt under aging. The low temperature rheological properties of AER modified asphalt and its composite modified asphalt under different aging conditions and different rubber powder content were studied using conventional performance, low temperature bending test and Burgers model. At the same time, the influence of aging on the functional group of AER rubber modified asphalt was quantitatively analyzed by infrared FTIR method, and the correlation between its functional group index and various low temperature indicators was analyzed. The results show that AER and SBS can improve the low temperature performance of asphalt under different aging conditions; the low temperature performance of AER/SBS composite modified asphalt is better than AER modified asphalt under short-term aging, while the opposite is true under long-term aging. Both AER and SBS modifiers can improve the stiffness modulus of asphalt and AER has a greater impact on asphalt stiffness modulus, while low temperature grading indexes (i.e., stiffness modulus S, creep rate m, and the ratio S/m) and viscoelasticity indexes (i.e., relaxation time λ and dissipation-storage energy ratio a has a strong correlation. The low temperature performance of AER modified asphalt has a high correlation with the fat index I_A and the fat long chain index I_AL: the greater the aliphatic index, the better the low temperature performance, while the aliphatic fat long chain index is the opposite.