不同抗剥落剂对胶粉改性沥青性能的影响

Effects of different anti-stripping agents on properties of crumb rubber modified asphalt

为探明不同抗剥落剂对胶粉改性沥青性能的影响,分析了3种不同类型的抗剥落剂(M1、T9和LOF-6500)及其掺量(质量分数为0.25%、0.50%和0.75%,下同)对胶粉改性沥青物理、流变、老化和与集料黏附性的影响。采用软化点、针入度、延度以及布氏旋转黏度试验测试胶粉改性沥青的物理性能,利用动态剪切流变仪测试了胶粉改性沥青的流变性能,使用薄膜烘箱老化试验(TFOT)和压力老化箱老化试验(PAV)分别模拟其短期和长期老化,并基于表面能试验测定了加入3种抗剥落剂的胶粉改性沥青与典型集料类型间的黏附功和剥落功。结果表明:M1、T9和LOF-6500有利于提升胶粉改性沥青的延展性和低温性能,适合于寒冷地区道路建设时使用,且在施工时无需调整拌合与压实温度;抗剥落剂的掺入并未改变胶粉改性沥青的高温性能等级(PG),对其高温性能影响较小,且有利于提升胶粉改性沥青的抗老化性能,其中,M1和LOF-6500对胶粉改性沥青的抗短期老化性能提升效果优于T9,但在抗长期老化性能提升上,T9和LOF-6500的效果明显优于M1。3种抗剥落剂均可增大胶粉改性沥青黏附功和减小剥落功,提升其与集料间的黏附性,有利于混合料的水稳定性提高,掺量0.75%的M1型或LOF-6500型抗剥落剂对胶粉改性沥青与集料黏附性提升效果最佳。综合考虑掺加抗剥落剂对胶粉改性沥青的物理、流变、老化和与集料的黏附性的影响,建议选用LOF-6500型抗剥落剂,且掺量0.5%~0.75%为宜。

In order to clarify the influence of different anti-stripping agents on the performance of crumb rubber modified asphalt,the effects of three kinds of anti-stripping agents(M1,T9 and LOF-6500)and their contents(0.25%,0.50%and 0.75%by the mass of asphalt binder,the same below)on the physical,rheological,aging and adhesion of crumb rubber modified asphalt were investigated.The physical properties of crumb rubber modified asphalt were tested by softening point,penetration,ductility and Brookfield rotational viscosity tests.The rheological properties of crumb rubber modified asphalt were tested by dynamic shear rheometer.The short-term and long-term aging of asphalt samples were simulated by thin-film oven aging test(TFOT)and pressure aging vessel(PAV),respectively.Also,the adhesion work and stripping work between the crumb rubber modified asphalt and the typical aggregate types were measured.The results show that M1,T9 and LOF-6500 are beneficial to improve the ductility and low temperature performance of crumb rubber modified asphalt,and are suitable for road construction in cold regions.There is no need to adjust mixing and compaction temperature during construction.The addition of anti-stripping agents has not changed the high-temperature performance grades of crumb rubber modified asphalt,meaning little effect on its high temperature performance,and is conducive to improving the anti-aging properties of crumb rubber modified asphalt.Specifically,M1 and LOF-6500 have better short-term aging resistance than T9,but T9 and LOF-6500 are better than M1 in improving long-term aging resistance.Besides,three kinds of anti-stripping agents can increase the adhesive work and reduce the stripping work of crumb rubber modified asphalt,improve the adhesion between crumb rubber modified asphalt and aggregate,and improve the water stability of mixture.And 0.75%dosage M1 or LOF-6500 has the best effect on improving the adhesion between crumb rubber modified asphalt and aggregate.Considering the influence of anti-stripping agents on the physical,rheological,aging and adhesion between aggregate and crumb rubber modified asphalt,LOF-6500 with a dosage ranging from 0.5%to 0.75%is recommended.5 tabs,16 figs,30 refs.