Wei Jianguo, Shi Song, Zhou Yuming, Chen Zhiyuan, Yu Fan, Peng Zhuyi, Duan Xurui
School of Traffic and Transportation Engineering, Changsha University of Science and Technology, Changsha 410004, China.
Henan Railway Construction & Investment Group Co., Ltd., Zhengzhou 450018, China.
Materials (Basel). 2022 Mar 13;15(6):2112. doi: 10.3390/ma15062112.
Although several studies indicated that the addition of Styrene-Butadiene-Styrene (SBS) and Styrene-Butadiene Rubber (SBR) bring a lot of benefits on properties of asphalt binders, high production costs and poor storage stability confine the manufacture of better modified asphalt. To reduce the production costs, polyphosphoric acid (PPA) was applied to prepare better compound modified asphalt binders. In this research, five PPA (0.5%, 0.75%, 1.0%, 1.25% and 1.5%) and two SBR/SBS (4% and 6%) concentrations were selected. Dynamic shear rheometer (DSR) and Bending Beam Rheometer (BBR) tests were performed to evaluate the rheological properties of the compound modified asphalt. Rolling Thin Film Oven (RTFO) test was performed to evaluate the aging properties of the compound modified asphalts. The results indicate that SBS/SBR modified asphalts with the addition of PPA show better high-temperature properties significantly, the ability of asphalt to resist rutting is improved, and the elastic recovery is increased. However, the low-temperature properties of the compound modified asphalts are degraded by increasing the creep stiffness (S) and decreasing the creep rate (m). At the same time, RTFO tests results show that PPA was less prone to oxidation to improve the anti-aging ability of modified asphalts. Overall, the combination of 4% SBS and 0.75-1.0% PPA, the combination of 4% SBR and 0.5-0.75% PPA is recommended based on a comprehensive analysis of the performance of compound modified asphalt, respectively, which can be equivalent to 6% SBS/SBR modified asphalt with high-temperature properties, low-temperature properties, temperature sensitivity and aging properties.
尽管多项研究表明，添加苯乙烯-丁二烯-苯乙烯（SBS）和丁苯橡胶（SBR）能给沥青结合料的性能带来诸多益处，但高昂的生产成本和较差的储存稳定性限制了性能更优的改性沥青的生产。为降低生产成本，采用多聚磷酸（PPA）来制备性能更优的复合改性沥青结合料。本研究中，选取了五种PPA浓度（0.5%、0.75%、1.0%、1.25%和1.5%）以及两种SBR/SBS浓度（4%和6%）。通过动态剪切流变仪（DSR）和弯曲梁流变仪（BBR）试验来评估复合改性沥青的流变性能。采用旋转薄膜烘箱（RTFO）试验来评估复合改性沥青的老化性能。结果表明，添加PPA的SBS/SBR改性沥青显著展现出更好的高温性能，沥青抵抗车辙的能力得到提高，弹性恢复增加。然而，随着蠕变劲度（S）增大和蠕变速率（m）降低，复合改性沥青的低温性能有所下降。同时，RTFO试验结果表明，PPA不易氧化，从而提高了改性沥青的抗老化能力。总体而言，基于对复合改性沥青性能的综合分析，分别推荐4% SBS与0.75 - 1.0% PPA的组合，以及4% SBR与0.5 - 0.75% PPA的组合，它们在高温性能、低温性能、温度敏感性和老化性能方面可等同于6% SBS/SBR改性沥青。
