细骨料级配对沥青混凝土力学性能影响研究

Study on the influence of fine aggregate gradation on the mechanical properties of asphalt concrete

心墙沥青混凝土的力学性能直接影响着土石坝工程的稳定及防渗安全。为了研究细骨料颗粒级配对沥青混凝土力学性能影响规律,在沥青、粗骨料、填料配合比相同的情况下,按细骨料颗粒级配分别设置了5种级配偏差:-20%、-10%、0%、10%、20%,并制作相应的沥青混凝土试件,对其进行相关性能试验分析。试验结果表明,细骨料颗粒级配对沥青混凝土力学性能有一定影响,细骨料中级配偏差由-20%增加至20%时,40℃马歇尔稳定度降低了3.2%、劈裂抗拉强度降低了12.7%、单轴压缩强度降低了8.7%,而应变值均呈现出不同程度的增加,40℃马歇尔流值增加了10.3%、劈裂抗拉对应变形增加了4.1%、单轴压缩应变值增加了8.9%。由此得出,细骨料颗粒级配是影响沥青混凝土力学性能的重要因素。

The mechanical properties of core wall asphalt concrete directly affect the stability and impermeability safety of earth-rock dam projects.In order to study the influence rule of fine aggregate particle gradation on the mechanical properties of asphalt concrete,five different particle gradations of fine aggregate are set with gradation deviations of -20%,-10%,0%,10% and 20%,respectively,under the same asphalt,coarse aggregate,and filler mix ratio.Corresponding asphalt concrete specimens are made and subjected to relevant performance tests and analysis.The test results show that the fine aggregate particle gradation has a certain influence on the mechanical properties of asphalt concrete.When the gradation deviation of the fine aggregate is increased from -20% to 20%,the Marshall stability at 40℃ decreases by 3.2%,the splitting tensile strength decreases by 12.7%,and the uniaxial compression strength decreases by 8.7%.Meanwhile,the strain values show different degrees of increase,with the Marshall flow value at 40℃ increasing by 10.3%,the splitting tensile corresponding strain increasing by 4.1%,and the uniaxial compression strain value increasing by 8.9%.Therefore,it can be concluded that the fine aggregate particle gradation is an important factor affecting the mechanical properties of asphalt concrete.