PE蜡温拌沥青与集料的界面作用研究

Study on the interfacial interaction between PE wax warm mix asphalt and aggregate

为研究废塑料裂解蜡(PEW)作为温拌剂对基质沥青与不同集料间界面作用的影响,以最佳掺量5%PEW与70#基质沥青混合制备成温拌沥青,通过Brookfield黏度分析PEW作为温拌剂对基质沥青的降黏效果;采用水煮法和水浸法分析不同粒径且不同集料(石灰岩、玄武岩和花岗岩)与温拌沥青的黏附效果,其中通过分析试验前后样品质量的变化,结合公式计算沥青残留率,更加直观地分析沥青与集料的黏附性;通过测定不同有机溶剂与沥青的接触角,基于表面自由能理论计算表面自由能和黏附功分析其黏附性。结果表明:掺量为5%PEW的温拌沥青的Brookfield黏度较基质沥青下降明显,拌合温度下降了20℃左右,且135℃的黏度较基质沥青下降了40.6%;传统的水煮法测出石灰岩与玄武岩的黏附等级相同均为5级,水浸法测出玄武岩与花岗岩的黏附等级相同均为3级,而引入沥青残留率可以定量分析水煮法与水浸法的试验结果,其中3种集料与两种沥青样品的黏附性由大到小依次是石灰岩、玄武岩、花岗岩;接触角试验所测得不同试剂与沥青样品接触角的大小为蒸馏水>丙三醇>甲酰胺,PEW的加入导致基质沥青的黏聚功从47.98mJ/m^(2)降低至37.06mJ/m^(2),降低了22.8%,不同沥青样品与不同集料在无水和有水状态下的黏附功大小为石灰岩>玄武岩>花岗岩,温拌沥青与集料的黏附功均小于基质沥青。

In order to study the effect of waste plastic cracking wax(PEW)as a warm mixing agent on the interfacial interaction between matrix asphalt and different aggregates,a warm mix asphalt was prepared by mixing the optimum content of 5%PEW with 70#matrix asphalt.The viscosity reduction effect of PEW as a warm mix agent on matrix asphalt was analyzed by Brookfield viscosity.The adhesion effect of different particle sizes and aggregates(limestone,basalt and granite)with warm mix asphalt was analyzed by boiling method and water leaching method.The change of sample quality before and after the test was analyzed,and the asphalt residue rate was calculated by combining the formula to analyze the adhesion of asphalt and aggregate more directly.By measuring the contact angle between different organic solvents and asphalt,the surface free energy and adhesion work were calculated based on the surface free energy theory to analyze the adhesion.The results showed that the Brookfield viscosity of the 5%PEW mixture decreased significantly compared with that of the matrix asphalt,the mixing temperature decreased by about 20℃,and the viscosity at 135℃decreased by 40.6%compared with that of the matrix asphalt.The traditional boiling method indicated that limestone and basalt had the same adhesion grades of 5,while the water leaching method showed the same adhesion grade of 3 for basalt and granite.The introduction of asphalt residue rate could quantitatively analyze the test results of the boiling method and the water leaching method,and the adhesion of the three aggregates and the two asphalt samples was,in descending order,limestone,basalt,and granite.According to the contact angle test,the contact angle between different reagents and asphalt samples was distilled water>glycerol>formamide.The addition of PEW resulted in a decrease of 22.8%in the cohesion work of asphalt matrix from 47.98mJ/m^(2) to 37.06mJ/m^(2).The adhesion work of different asphalt samples and aggregates in anhydrous and hydrous states was limestone>basalt>granite,and the adhesion work of warm mix asphalt and aggregates was smaller than that of matrix asphalt.