硫改性沥青机理分析

游离硫与交联硫的结构、性能差异较大，对沥青作用机理截然不同。应用聚合物补强、增韧等改性理论对这两种不同形式的硫的改性机理分别进行分析。认为游离硫对高温性能改善不明显并降低低温性能，交联硫则能同时改善高、低温性能。根据游离硫、交联硫含量与延度的对应关系，认为硫的存在形式是影响沥青低温性能的关键因素。当游离硫与交联硫比例大于6．5时沥青低温变形能力降低，小于6．5时低温变形能力提高。可利用此比例作质量控制指标，并应采取各种措施降低此比例以提高硫改沥青性能。从粘附面积、强度两方面分析粘附性能，认为硫改性沥青对石料润湿能力强，极性强，酸值高，能改善沥青一石料粘附性。分析老化因素及老化阶段，认为硫改性沥青能抑制各种老化因素的作用，并减小高温施工阶段的物理老化。

Study on Mechanism of Sulphur Modified Asphalt

Because of the great difference between free sulphur and cross-linking sulphur in structure, performance and modification mechanism, this paper analyses the mechanism of sulphur modified asphalt from two aspects of free sulphur and cross-linking sulphur, applying the theory of reinforcing and toughening polymer. The free sulphur can＇ t improve high-temperature performance and does harm to low-temperature performance while cross-linking sulphur can improve high - temperature and low-temperature performance together. According to the relationship between ductility and content of free and cross-linking sulphur, the form of sulphur is the key factor of low-temperature performance. When the proportion of free sulphur and cross-linking sulphur is higher （lower） than 6.5/1.0, the ductility performance of asphalt becomes worse（better）. This proportion can be used as evaluating index, and polytechnic measure can be taken to reduce the proportion for high performance. Sulphur modified asphalt has higher wetting ability, stronger polarity and higher acidity, so the adhesion area is bigger, adhesion strength is higher, and asphalt-rock is stronger. Asphalt with cross-linking structure can resist aging factors and prevent physical aging in the process of high-temperature construction.