SBS 改性高 RAP 掺量热再生混合料温度敏感性及抗裂性能研究

摘要

热再生混合料 RAP 回收利用率低、抗裂性能不足是制约其适用性的关键技术指标，提出采用 SBS改性沥青生产厂拌热再生混合料，并基于车辙试验、小梁弯曲试验、四分点加载控制应变疲劳试验研究了不同 RAP掺量热再生混合料的温度敏感性、低温抗裂性抗疲劳开裂性能。试验结果表明：相比 SBS 改性沥青混合料，SBS 改性热再生混合料具有较好的抗永久变形能力，且随着 RAP 掺量增大改性热再生混合料温度敏感性降低；随着 RAP掺量增加，改性热再生混合料弯拉应变、单位体积破坏应变能均呈线性减小，RAP 掺量小于40％时，增大 RAP 掺量对改性热再生混合料低温抗裂性影响不大，RAP 掺量超过50％时，SBS 改性改性热再生混合料的疲劳性能显著降低，低温抗裂性和抗疲劳耐久性仍是制约改性热再生混合料 RAP 掺量的主要因素。%The RAP recycling utilization is low and the crack resistance is a key technology that limit the applicability of the indicators,In article using the SBS modified asphalt plant mix hot recycled mixture,and based on the rutting test,the trabecular bending test,four point load control strain fatigue test to study the temperature sensitivity,low temperature crack resistance,resistance to fatigue cracking performance of hot recycled mixture under different RAP content.The results show that:compared with SBS modified asphalt mixture,the SBS modification of hot recycled mixture has good ability to resist per-manent deformation,and the with the increase of RAP dosage,mixture temperature reduced susceptibili-ty;With the increase of dosage of RAP,modified hotrecycled mixture flexural strain and damage strain energy per unit volume is linearly decreases,and RAP content less than 40%,increasing the RAP con-tent of modified hot regeneration mixture has a little influence on the low temperature crack resistance, RAP content exceeds 50%,the fatigue property of modified SBS modified hot regeneration mixture signif-icantly reduced,low temperature crack resistance and fatigue resistance durability is still restricted modi-fied the main factors of hot recycled mixture RAP content.