乳化沥青冷再生混合料性能优化及机理研究

Performance Optimization and Mechanism of Emulsified Asphalt Cold Recycled Mixtures

关键词:  乳化沥青冷再生混合料  路用性能  多指标加权  性能优化  抗裂增强机理

Key words:  emulsified asphalt cold recycled mixture  road performance  multi index weighted method  performance optimization  anti cracking enhancement mechanism

摘要:

为提升华南湿热地区乳化沥青冷再生混合料的路用性能，研究了乳化沥青用量、水泥掺量及铣刨料（RAP）掺量对冷再生混合料高温性能、水稳性能及疲劳性能的影响规律.通过多指标加权分析，对冷再生混合料进行了性能优化及影响因素优选，并借助扫描电镜（SEM）揭示了水泥乳化沥青胶浆的抗裂增强机理.结果表明：乳化沥青用量和水泥掺量对冷再生混合料高温性能的影响最为显著，RAP掺量对其水稳性能的影响最大，不同应力比下冷再生混合料疲劳性能受各因素影响的显著性存在差异；当乳化沥青用量（质量分数，下同）为35%，水泥掺量为20%，RAP掺量为80%时，冷再生混合料的综合性能最佳；水泥乳化沥青胶浆能改善冷再生混合料微观界面变形协调性，使其更好地传递和分散应力，减缓裂缝发育速率，抗裂效果显著.

Abstract:

In order to improve road performance of emulsified asphalt cold recycled mixtures in south China moist hot areas, the effects of emulsified asphalt content, cement content and reclaimed asphalt pavement（RAP）content on high temperature performance, water stability and fatigue property of cold recycled mixtures were studied. Based on multi index weighted method, the performance of cold recycled mixture and its influencing factors were optimized, the anti cracking enhancement mechanism of cement emulsified asphalt mortar was revealed by scanning electron microscopy. The results show that high temperature performance of cold recycled mixtures is mainly affected by emulsified asphalt dosage and cement content, while water stability is significantly affected by RAP content, and the fatigue property is significantly affected by various factors under different stress ratios. When the emulsified asphalt dosage is 35%（by mass, the same below）, the cement content is 20% and the RAP content is 80%, the overall performance of cold recycled mixtures reaches the best. The cement emulsified asphalt mortar can improve the micro interface deformation coordination of cold recycled mixtures, make it better to transmit and disperse the stress, and slow down the crack development rate which is remarkable for crack resistance.