Dziadosz Sylwia, Słowik Mieczysław, Niwczyk Filip, Bilski Marcin
Faculty of Civil and Transport Engineering, Poznan University of Technology, Piotrowo 3, 60-965 Poznań, Poland.
Institute of Civil Engineering, Faculty of Civil and Transport Engineering, Poznan University of Technology, Piotrowo 5, 61-138 Poznań, Poland.
Materials (Basel). 2021 May 27;14(11):2888. doi: 10.3390/ma14112888.
The paper presents the results of laboratory investigation on asphalt binders relaxation at low temperature, carried out in a ductilometer using the tensile test with continuous force measurement. Polymer modified asphalt binder samples consisting of a 50/70 penetration grade bitumen mixed with a concentrate of styrene-butadiene-styrene (SBS) modified bitumen-a 160/220 penetration grade bitumen modified with a SBS copolymer in the amount of 9%-were tested. Therefore, polymer modified binders containing 3%, 4.5%, 6% and 7.5% SBS, respectively, were obtained and investigated. Tensile tests were performed at -16 °C on samples before aging and subjected to short-term aging (RTFOT). Test results in the form of relaxation curves have been mathematically described using a modified generalized Maxwell model. Based on the acquired results, it was shown that the increase of the SBS copolymer content in asphalt binder precipitates the relaxation process, while aging slows down this phenomenon. It has also been proven that with increased content of SBS elastomer in asphalt binder, the effect of short-term aging on binder's stress relaxation ability at low temperatures is reduced.
本文介绍了在延度仪中使用连续力测量拉伸试验对沥青结合料低温松弛进行的实验室研究结果。测试了由50/70针入度级沥青与苯乙烯-丁二烯-苯乙烯（SBS）改性沥青浓缩物混合而成的聚合物改性沥青结合料样品，该浓缩物为用9%的SBS共聚物改性的160/220针入度级沥青。因此，分别获得并研究了含有3%、4.5%、6%和7.5%SBS的聚合物改性结合料。在-16°C下对未老化和经过短期老化（旋转薄膜烘箱试验，RTFOT）的样品进行拉伸试验。使用改进的广义麦克斯韦模型对以松弛曲线形式呈现的试验结果进行了数学描述。基于所获得的结果表明，沥青结合料中SBS共聚物含量的增加会促使松弛过程加快，而老化会减缓这一现象。还证明了随着沥青结合料中SBS弹性体含量的增加，短期老化对结合料低温应力松弛能力的影响会降低。
