SBR/有机膨润土矿物复合改性沥青及混合料技术性能分析

李明扬 肖庆一 何川 任希鹏

摘要 膨润土以其对沥青良好的改性效果与低廉的价格常作为沥青的改性剂，其硅酸盐结构对沥青低温性能存在负面影响;丁苯橡胶（SBR）能显著提高改性沥青低温延度，降低温度敏感性，对高温性能提升有限。由单掺膨润土、SBR及复合改性（膨润土、SBR）后沥青的基础性能试验结果表明，两种改性剂复合改性可以相互克服单一改性剂的缺点，增强优势。PG分级和BBR试验结果表明，复合改性沥青高温失效温度和低温劲度模量极限温度均满足华北地区气候条件的要求。采用AC-13型、SMA-13型两种沥青混合料进行路用性能研究，结果表明通过采用复合改性技术的混合料高低温性能、水稳定性及耐疲劳性能均得到不同程度的改善提高。相比于SBS改性沥青技术，研究提出的复合改性沥青技术具有更好的路用性能表现及社会经济效益。

关 键 词 纳米膨润土;SBR;流变学试验;路用性能;经济效益

中图分类号 U414     文献标志码 A

Abstract Bentonite is often used as asphalt modifier for its good modification effect on asphalt and low price， but its silicate structure has a negative impact on the low temperature performance of asphalt; SBR can significantly improve the low temperature ductility of modified asphalt and reduce Temperature sensitivity，but with limited high temperature performance improvement. From the test results of the three major indexes of single-mixed bentonite， SBR and the two composite asphalts， it can be seen that the two modifiers can overcome each other's shortcomings and enhance their advantages. The PG classification and BBR test results show that both the high temperature failure temperature and the low temperature stiffness modulus limit temperature meet the temperature limit conditions in North China. Two gradations of AC-13 type and SMA-13 type are used to prepare composite modified asphalt mixture. According to the laboratory tests， the high and low temperature， water stability and fatigue resistance of the mixture have been improved. Compared with SBS， composite modified asphalt has better road performance and social economic benefits.

Key words nano bentonite; SBR; rheological test; road performance; economic benefit

0 引言

蒙脱土是一种具有天然的纳米级微观结构且亲水疏油的无机物，其表面经有机修饰后，可获得疏水亲油性[1]，与沥青充分结合形成剥离型或插层型纳米复合型结构，提高沥青的高温性能和流变性能。以蒙脱土为代表的硅酸盐类改性剂会伤害沥青低温性能，需添加外掺剂进行复合改性[2]。部分橡胶、树脂类材料以对低温的不敏感性及较低廉的价格，常被选做改性剂，树脂类改性剂和沥青相容性一般差距较大，无法很好地分散在沥青相中，很容易发生离析分层现象[3]。……