PPA/LSBR复合改性沥青及混合料性能研究

Research on properties of PPA/LSBR composite modified asphalt and mixture

为研究多聚磷酸(PPA)和液体丁苯橡胶(LSBR)复合改性沥青与混合料路用性能,选用2.0%掺量的LSBR和0.3%、0.6%、0.9%、1.2%、1.5%的PPA进行复配,采用针入度、软化点、延度、旋转黏度以及四组分试验,分析了改性沥青基本性能、感温性能以及组分变化;通过车辙试验、低温小梁弯曲试验、浸水马歇尔试验以及冻融循环试验,研究了复合改性后混合料的路用性能变化。结果表明,PPA可以有效改善LSBR改性沥青的温度敏感性,高温性能得到提升;随着PPA含量的增加,沥青质逐渐增加,胶质减小,导致沥青黏度增加;PPA/LSBR复合改性沥青混合料动稳定度较LSBR提高了77.2%,表现出良好的高温性能,破坏应变和冻融劈裂比较LSBR分别减小了6.1%与2.79%,但仍高出SBS改性沥青混合料2.0%与2.3%,其综合性能最佳。

In order to study the pavement performance of polyphosphate(PPA)and liquid styrene butadiene rubber(LSBR)composite modified asphalt and mixture,LSBR with 2.0%content and PPA with 0.3%,0.6%,0.9%,1.2%and 1.5%content are selected for compounding.Penetration,softening point,ductility,rotational viscosity and four component tests are adopted to analyze the basic performance,temperature sensing performance and component changes of the modified asphalt.The road performance changes of the composite modified mixture were studied by rutting test,low temperature trabecular bending test,immersion Marshall test and freeze-thaw cycle test.The results show that PPA can effectively improve the temperature sensitivity and high temperature performance of LSBR modified asphalt;With the increase of PPA content,asphaltene gradually increases and colloid decreases,resulting in the increase of asphalt viscosity;The dynamic stability of PPA/LSBR composite modified asphalt mixture is 77.2%higher than that of LSBR,showing good high temperature performance,Compared with freeze-thaw splitting,the failure strain and freeze-thaw splitting of LSBR are reduced by 6.1%and 2.79%respectively,but it is still 2.0%and 2.3%higher than that of SBS modified asphalt mixture,and its comprehensive performance is the best.