王辉 熊梦日 杨震

摘   要：為探究废胶粉复合改性沥青性能与改性机理，采用软化点、5 ℃延度、弹性恢复、动态剪切流变试验指标等来评价其性能，通过微观形貌观测、红外光谱图、差示扫描量热法进行微观分析，将其与普通胶粉改性沥青、基质沥青进行对比，分析废胶粉复合改性沥青的改性机理. 结果表明，废胶粉复合改性沥青具有更高的PG高温等级，表现出更好的高温性能;储存48 h废胶粉复合改性沥青仅有少量的废胶粉大颗粒开始被沥青胶团吸附并下沉，至储存72 h后才出现明显的离析现象，储存稳定性能得到明显改善;微观形貌下废胶粉复合改性沥青大部分胶粉颗粒均匀分散在沥青中，排列致密，形成亚均相结构;废胶粉复合改性沥青表现为物理共混改性的同时存在化学反应;相较于单一的物理改性，在复合改性的作用下，整个体系呈致密交联型网络状结构，使得分子间结合牢固，低温性能方面表现更好.

关键词：改性沥青;废胶粉;化学改性;路用性能;储存稳定性;改性机理

中图分类号：U414                                文献标志码：A

Research on Performance and Mechanism of Crumb Rubber

Composite Modified Asphalt with Chemical Modifier

WANG Hui?，XIONG Mengri，YANG Zhen

（School of Traffic and Transportation Engineering，Changsha University of Science and Technology，Changsha 410114，China）

Abstract：In order to investigate the performance and modification mechanism of crumb rubber composite modified asphalt with chemical modifier，the conventional indexes such as softening point，5 ℃ ductility，elastic recovery rate，dynamic shear rheology test indexes are used to evaluated its performance. Compared with ordinary rubber-modified asphalt and SBS modified asphalt，the microscopic modification mechanism of crumb rubber composite modified asphalt was conducted by scanning electron microscope，Fourier infrared spectroscopy，and differential scanning calorimetry. The results show that crumb rubber composite modified asphalt has a higher failure temperature for performance grade（PG） of asphalt binder and shows better high-temperature performance. It can be known from the fluorescence microscope test，after 48 hours of storage，only some large rubber powder particles began to be adsorbed by the asphalt micelles and sank in the crumb rubber composite modified asphalt. After 72 hours of storage，the segregation has occurred obviously. Under the microscopic morphology， most of the rubber powders were evenly dispersed in the asphalt，arranged densely，and formed a sub-homogeneous structure in the crumb rubber composite modified asphalt. The infrared spectroscopy and the differential scanning calorimetry tests show that the physical blending modification and the chemical reaction existed simultaneously in the crumb rubber composite modified asphalt. Compared with a single physical modification， under the action of compound modification，the entire system appears a dense cross-linked network structure，which makes the intermolecular bonding firm，and performs better in terms of low-temperature properties.

Key words：modified asphalt;crumb rubber;chemical modification;pavement performance;storage stability;modification mechanism

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