坡缕石改性沥青混合料施工稳定性研究

Study on Construction Stability of Palygorskite Modified Asphalt Mixture

采用沥青离析试验、添加物含量对比试验、马歇尔强度试验以及冻融劈裂试验,系统研究了坡缕石粉对SBS改性沥青的相容稳定性和沥青混合料的路用性能稳定性的影响规律。试验结果表明,坡缕石表面改性能够减少与沥青的离析程度,提升坡缕石粉与沥青的相容性;采用湿法拌合,坡缕石改性沥青混合料的马歇尔强度及冻融劈裂强度比均为最优;采用干法拌合,增加拌合时间,也能够达到湿法拌合的效果。基于此,对于无机微粉类改性沥青应先进行表面改性,采用湿法拌合施工;也可增加拌合时间,采用干法进行拌合施工。

The influence of palygorskite on the compatibility stability of SBS modified asphalt and the road performance stability of asphalt mixtures were studied by asphalt segregation test,additive content comparison test,Marshall strength test and freezethaw splitting test.The results showed that,the degree of segregation between palygorskite powder and asphalt was reduced,the compatibility between palygorskite powder and asphalt was improved by surface modification.The Marshall strength and the freezethaw splitting strength ratio of palygorskite modified asphalt mixture were the best via wet mixing,the effect of Marshall strength and freeze-thaw splitting strength ratio were the same as wet mixing by increasing mixing time when the dry mixing method was used.Based on this,the construction of inorganic micro powder modified asphalt mixture should adopt by wet mixing,and surface modification of inorganic substances should be used firstly.And dry mixing can be used via increasing the mixing time.