双螺杆挤出胶粉与RET复合改性沥青及其混合料性能研究

为解决传统橡胶沥青黏度大、施工温度高、易发生离析沉淀和橡胶粉掺量低的问题,采用微波活化和双螺杆挤出工艺对橡胶粉进行脱硫降解,同时为了进一步解决双螺杆挤出胶粉改性沥青高温性能损失大的问题,提出采用双螺杆挤出胶粉与反应型三元共聚物(RET)复配方案。采用针入度体系指标性能和Superpave沥青胶结料PG分级体系研究了10%、20%、30%橡胶粉复配0.5%、1.0%、1.5%RET改性沥青性能,进而通过三大路用性能试验和实体工程跟踪检测,验证了双螺杆挤出胶粉与RET复合改性沥青混合料路用性能。结果表明,用于TECRM/RET复合改性沥青适宜的双螺杆挤出胶粉掺量为20%~30%、RET掺量为1.0%~1.5%。在此复配方案下,TECRM/RET复合改性沥青的135℃黏度小于3.5 Pa·s、软化点大于65℃、25℃针入度40~60(0.1 mm)、25℃弹性恢复率大于80%、离析软化点差小于3.0℃,高低温PG分级达到了82、-24℃;双螺杆挤出胶粉改性沥青避免了普通橡胶沥青粘度大、易离析等弊端,是一种高低温性能和施工和易性能兼顾的改性沥青产品。相比SBS改性沥青混合料,TECRM/RET复合改性沥青混合料有突出的高低温性能和水稳定性优势。实体工程应用取得了优良的使用效果,研究成果为双螺杆挤出胶粉改性沥青推广应用提供可靠的技术保障。

Study on Properties of Twin-screw Extrusion Crumb Rubber Powder and RET Composite Modified Asphalt and Asphalt Mixture

In order to solve the problem of high viscosity,high construction temperature,easy segregation and precipitation,and low rubber powder content of traditional rubber asphalt,the rubber powder is desulfurized and degraded by microwave activation and twin-screw extrusion process,At the same time,in order to further solve the problem of large loss of high temperature performance of twin-screw extruded rubber powder modified asphalt,A double-screw extrusion rubber powder and a reactive terpolymer(RET)composite modified method were proposed.Using the performance of the penetration system index and the Superpave asphalt binder PG classification system,the performance of 10%,20%,30%rubber powder compounded 0.5%,1.0%,1.5%RET modified asphalt was studied,and then using the three roads performance test,And physical engineering tracking test,verifying the road performance of twin-screw extrusion rubber powder and RET composite modified asphalt mixture.The results show that the suitable amount of twin-screw extrusion rubber powder for TECRM/RET composite modified asphalt is 20%~30%,and the RET dosage is 1.0%~1.5%.Under this compounding scheme,the TECRM/RET composite modified asphalt 135℃viscosity is less than 3.5 Pa·s,softening point more than 65℃,25℃penetration is 40~60(0.1 mm),and 25℃elastic recovery rate is more than 80%,the separation softening point difference is less than 3.0℃,high and low temperature PG classification reaches 82℃,-24℃;twin-screw extrusion rubber powder modified asphalt avoids the disadvantages of ordinary rubber asphalt viscosity,easy segregation,etc.,The twin-screw extrusion rubber powder modified asphalt avoids the disadvantages of high viscosity and easy segregation of ordinary rubber asphalt,and is a modified asphalt product with high and low temperature performance,and ease construction performance.Compared with SBS modified asphalt mixture,TECRM/RET composite modified asphalt mixture has outstanding advantages of high and low temperature performance and water stability.The application of physical engineering has achieved excellent use results,and the research results provide reliable technical support for the promotion and application of twin-screw extruded rubber powder modified asphalt.