ABSTRACT

Polyethylene (PE) and polyethylene glycol (PEG) with three different molecular weights are employed to modify bitumen, which is denoted as the polymer-modified bitumen (PMB). The samples, PMB-L, PMB-M and PMB-H, indicate PE/PEG modified bitumen in which PEG molecular weight is from low to high. PEGs and PMBs exhibit different crystallisation and melting behaviours measured by a differential scanning calorimeter. Rutting resistance and elastic property of PMBs under high temperature are studied by a rheometer. By analysing the complex modulus variation with temperature increment, it is found that the rheological stability is better for PMB-L and PMB-H, revealing a non-monotonous relationship with PEG molecular weight. The mechanical property of PMBs under low temperature is detected by their tensile behaviour and glass transition temperature, both of which reflect the weak ductility and low-temperature property of PMB-H. The reason for different properties of PMBs is interpreted by the phase structure and their stability, especially by the size and location of the PEG-rich phase.

摘要

采用三种不同分子量的聚乙烯（PE）和聚乙二醇（PEG）对沥青进行改性，称为聚合物改性沥青（PMB）。样品PMB-L、PMB-M和PMB-H表示PEG分子量从低到高的PE/PEG改性沥青。PEG 和 PMB 表现出不同的结晶和熔化行为，由差示扫描量热仪测量。通过流变仪研究了高温下PMBs的抗车辙性能和弹性性能。通过分析复数模量随温度升高的变化，发现PMB-L和PMB-H的流变稳定性更好，与PEG分子量呈非单调关系。低温下PMBs的力学性能通过它们的拉伸行为和玻璃化转变温度来检测，两者都反映了 PMB-H 的弱延展性和低温特性。PMBs 不同性质的原因可以通过相结构及其稳定性来解释，尤其是富含 PEG 相的大小和位置。