改性纳米SiO_2对再生沥青胶结料性能的影响

Effects of nano-SiO_2 with modified surface on properties of recycled asphalt binder

为提高再生沥青的再生效果,文中采用RA-F0110型再生剂作为A型再生剂和OP-900型再生剂作为B型再生剂对旧沥青进行再生;采用硅烷偶联剂KH-550和KH-570对纳米SiO_2进行有机化表面改性;对比不同速率、不同搅拌时间、不同静置时间下纳米再生沥青的PG高温分级温度,确定纳米再生沥青的制备方法;对比添加不同种类不同掺量再生剂后再生沥青的PG连续分级确定再生剂的种类和掺量;对比不同纳米SiO_2掺量下纳米再生沥青的PG连续分级确定纳米材料的掺量。试验表明:纳米SiO_2在表面改性后团聚现象减少。纳米粒子被包覆,所以纳米粒子尺寸增大导致单个粒子的比表面积明显减小,纳米SiO_2在沥青中更加稳定,采用KH-550表面改性剂的效果优于KH-570。选用A型再生剂的再生沥青的再生效果优于选用B型再生剂的再生沥青。在相同再生剂掺量下,添加一定比例的纳米SiO_2,纳米再生沥青PG连续分级的高低温服务范围更宽广。当纳米材料的掺量为5%,A型再生剂掺量为15%时,纳米再生沥青胶结料的性能指标达到最佳。

In order to improve recycling capability of recycled asphalt, RA-F0110 recycling agents and OP-900 recycling agents are selected as A and B recycling agents for old asphalt, respectively;silance coupling agents KH-550 and KH-570 are used for surface modification of the nano-SiO?;the preparation method of nano-recycling asphalt was determined by comparing the performance graded HT of nano-recycling asphalt under different rates, different stirring time and different standing time;based on the performance graded tests with different kinds and different mixing amount of recycling agents, the kind of recycling agents and the mixing amount of recycling agents were determined;in the performance graded tests of DSR & BBR, the additive amount of nanophase materials was determined. The test results show that: after the surface modification of nano?SiC)2, the occurrence of agglomeration is reduced. Because the nano-SiO2 particles were wrapped, so that the increased size of nano?SiC)2 may lead to the obvious decrease of the specific surface area of individual particles, and the nano-SiO2 can be more stable in the asphalt. The improvement effect of KH-550 surface modifier shall be better than that of KH?570. The regeneration effects of the recycling agent A are better than those of the recycling agent B. With the same mixing amount of recycling agents, the recycling asphalt mixed with a certain proportion of nano?SiO2 can receive wider service temperature ranges with continous grading. When the mixing amount of nano?SiO2 is 5% and the amount of the recycling asphalt A is 15%, the optimal performance indexes can be attained for the nano-recycling asphalt.