心墙沥青混凝土孔隙率影响因素试验研究

Experimental Study on Influencing Factors of Porosity of Hydraulic Core Wall Asphalt Concrete

孔隙率为心墙沥青混凝土重要技术控制指标,其影响因素研究对沥青混凝土质量控制具有重要意义。在击实次数相同情况下,采用控制变量的方法,系统研究4种级配指数、4种沥青含量、4种填料含量条件下标准马歇尔试件孔隙率的变化规律。结果表明,沥青混凝土孔隙率随级配指数的增大而减小;随沥青含量的增大,呈先增大后减小趋势,沥青含量转折点为6.8%;随填料含量的增大,呈先减小后增大趋势,填料含量转折点为12%。灰色关联分析结果表明,级配指数对孔隙率的影响最大,填料含量次之,沥青含量最弱,且级配指数和填料含量对孔隙率的影响较大。研究结果可为目标孔隙率下心墙沥青混凝土配合比设计提供参考。

Porosity is an essential technical control index of core wall asphalt concrete,and the study of its influencing factors is of great significance to the quality control of asphalt concrete.Under the same number of compactions,using the method of control variables,the porosity variation of the standard Marshall specimen under the conditions of four gradation indexes,four asphalt contents,and four filler contents was systematic.The results show that the porosity of asphalt concrete decreases with the increase of the gradation index.With the rise of asphalt content,the porosity increases and decreases,and the turning point of asphalt content is 6.8%.With the growth of filler content,the porosity first decreases and then increases,and the turning point of filler content is 12%.The grey correlation analysis results illustrate that the gradient index has the most significant influence on the porosity,followed by the filler content,and the bitumen content is the weakest;additionally,the gradation index and filler content have a significant influence on porosity.These results can provide a reference for the design of asphalt concrete proportion for core walls with target porosity.