橡胶沥青老化性能的试验研究

Experimental research on aging properties of rubber asphalt

为了研究橡胶沥青的老化特征与规律,选取营口70~#和盘锦90~#2种基质沥青以及由其改性得到的橡胶沥青胶浆进行室内模拟老化试验,并将原样基质沥青与橡胶沥青胶浆进行对比,从针入度、软化点、延度以及弹性恢复4个角度进行分析。试验结果表明:废旧轮胎橡胶粉具有改善沥青胶浆性能的作用,能够降低沥青胶浆的针入度,但是由于胶浆中胶核的存在,需要增加试验数量才能保证试验的准确性;5℃和15℃延度的试验结果显示,为保障橡胶沥青胶浆稳定的延度性能,180℃施工时胶粉的掺入量应大于15%;随着胶粉掺量的增加,弹性恢复改变率逐渐趋于稳定。

In order to study the rubber asphalt aging characteristics and laws,selecting No.70 and No.90 two matrix asphalt and the rubber asphalt mortar modified by them to conduct indoor simulating aging test. And compared the original matrix asphalt with rubber asphalt mortar, analyzing it from the four angles of penetration, softening point,ductility and elastic recovery. The test results showed that waste rubber powder has the effect to improve the performance of asphalt mortar and can reduce the penetra- tion of asphalt mortar. But because of the existence of colloidal nucleus in mortar, it needs to increase the number of test to ensure the test accuracy. The results of 5℃ and 15 ℃ ductility tests show that the mixed powder amount should be greater than 15% when the construction temperature is 180 ℃ to guarantee the stable ductility performance of the rubber asphalt mortar. With the increase of rubber powder dosage, elastic recovery change rate gradually stabilized.