公路工程

为了解决现有冷铺冷拌乳化沥青混合料高温稳定性、黏结强度等不足,研究了SBR、SBS、水性环氧树脂、VAE乳液改性乳化沥青及乳化沥青混合料性能。采用先改性后乳化方法制备4种改性乳化沥青,基于改性乳化沥青蒸发残留物针入度、5℃延度、软化点、黏韧性试验确定了最佳改性剂掺量,并利用劈裂强度试验、无侧限抗压强度试验、动态压缩模量试验、贯入剪切试验和三大路用性能试验、四点弯曲疲劳试验、室内小型加速加载试验(MMLS1/3)对比分析了不同改性乳化沥青混合料的力学性能、路用性能和耐久性。结果表明,掺加SBR、SBS、水性环氧树脂、VAE这4种改性剂均可以显著提高乳化沥青的高温性能和黏韧性,建议用于乳化沥青改性剂时,SBR、SBS、水性环氧树脂、VAE这4种改性剂应不超过5%为宜。掺加SBR、SBS、水性环氧树脂、VAE这4种改性剂均可以显著提高乳化沥青混合料的力学性能、路用性能、抗疲劳性能和高温长期稳定性。建议将SBS、水性环氧树脂和VAE改性乳化沥青混合料应用于南方潮湿、高温多雨地区,SBR改性乳化沥青可用于我国北方等寒冷地区。工程实践表明,SBS、水性环氧树脂和VAE改性乳化沥青混合料兼具预防性与修复性养护功能,全寿命周期养护投资综合效益高,具有推广应用价值。

In order to solve the shortcomings of high temperature stability and bond strength of cold-cold emulsified asphalt mixture, the properties of SBR, SBS, waterborne epoxy resin, VAE emulsion modified emulsified asphalt and emulsified asphalt mixture were studied. Four modified emulsified asphalts were prepared by first modified emulsification method. The optimum modifier dosage was determined based on the penetration degree of modified emulsified asphalt evaporation, 5 ℃ ductility, softening point and viscosity test. Cleavage strength test, unconfined compressive strength test, dynamic compression modulus test, penetration shear test and three road performance test, four-point bending fatigue test, indoor small accelerated loading test(MMLS1/3) Mechanical properties, road performance and durability of different modified emulsified asphalt mixtures. The results show that the addition of SBR, SBS, waterborne epoxy resin and VAE can significantly improve the high temperature performance and viscosity of emulsified asphalt. It is recommended for SBR, SBS, waterborne epoxy when used as emulsified asphalt modifier. Resin, VAE four modifiers should not exceed 5%. Adding SBR, SBS, waterborne epoxy resin and VAE four modifiers can significantly improve the mechanical properties, road performance, fatigue resistance and long-term stability of emulsified asphalt mixture. SBS, waterborne epoxy resin and VAE modified emulsified asphalt mixture are recommended for use in humid, high temperature and rainy areas in the south. SBR modified emulsified asphalt can be used in cold regions such as northern China. The engineering practice shows that SBS, waterborne epoxy resin and VAE modified emulsified asphalt mixture have both preventive and repairing maintenance functions, and the comprehensive life cycle maintenance investment has high comprehensive benefits and has the value of popularization and application.