高弹嵌段共聚物功能性微结构与沥青改性效应

Functional microstructure of high elastic block copolymer and modification effect on asphalt

为了实现聚脲弹性体(polyurea elastomer,PUA)材料对沥青路面材料的改性效应,基于其优良的承载及荷载分散特性,制备PUA颗粒及粉质材料,识别和表征PUA颗粒不同断面中的典型功能性微结构,明确典型结构的分布特点,分析PUA粉质材料的粒径组成及特征,解析低温精细研磨工艺对PUA材料中功能性结构的损坏效应,确定不同粒径PUA粉质材料对沥青流变性能的影响规律。研究结果表明:不同PUA粉质材料的粒度呈现正态分布特征,且不同PUA材料粒度组成之间均有交集;扫描微区中不同直径的球状结构呈现出独立存在状态,而且直径不同的球状结构之间形成了局部三角式分布;0.15和0.075 mm PUA颗粒微观形貌中的球状结构已不完整,部分出现明显的切割破坏;PUA材料能够显著降低沥青材料受到加载荷载重复后的累积变形,改善了沥青受荷载作用后的弹性恢复能力。

Based on the excellent load bearing and dispersing characteristics of PUA(polyurea elastomer)materials,PUA particles and silty materials were prepared to achieve its modification effect on asphalt pavement materials in this article.The typical functional microstructures in different sections of PUA particles were identified and characterized to clarify the distribution characteristics of typical structures.The particle size composition and characteristics of the PUA powder material were analyzed to investigate the damage effect of the low-temperature fine grinding process on the functional structures of the PUA material.The influence of PUA powder materials with different particle sizes on the rheological properties of asphalt was studied and determined.The research results show that the particle size distribution of different PUA silty materials presented the normal distribution characteristic,and the particle size composition of different PUA materials had the intersection.The spherical structures of different diameters in the scanning micro-area existed independently in the material section,and the spherical structures formed the triangular distribution in specific zone.The spherical structures in the micro morphology of 0.15 and 0.075 mm PUA particles are incomplete,and some obvious cutting failures appeared.PUA materials could reduce the cumulative deformation of asphalt materials suffering from repeated loads and improve the elastic recovery ability of asphalt after being loaded.2 tabs,13 figs,30 refs.