密级配沥青混合料压实特性分析研究

Analysis and Study on the Compaction Characteristics of Dense Aggregate Asphalt Mixtures

为了对密级配沥青混合料的压实特性进行对比分析,采用Superpave设计法对设计的4种级配混合料的密实度曲线自然坐标下Nini、Ndes时的压实速率,半对数坐标下N_(ini)~N_(des)平均压实速率以及能量特性参数CEI、TDI_(96)、TDI_(98)进行了分析。分析结果显示:随着沥青用流量的增加,沥青所起到的润滑作用增强,混合料的可压实性增大;在减少中间部分骨料增加细集料用量情况下,骨架形成的内摩阻力在施工期可以实现在低沥青用量下达到压实效果,降低了施工期的设备能耗,能量特征参数表明经过压实达到预期密实效果后,骨架内摩阻力得到突显,可抵抗更多的交通荷载作用;对密实度曲线斜率和能量特性参数综合对比分析,表明采用能量特性指数相比曲线斜率能更加合理的表征密级配沥青混合料的压实特性。

In order to compare and analyze the compaction characteristics of dense aggregate asphalt mix-tures,the compaction rate under natural coordinates,average compression rate N_(ini)~N_(des) under semi-logarith-mic coordinates and real velocity and energy characteristic parameters CEI,TDI_(96),TDI_(98) of four kinds of de-signed aggregate mixtures density curves are analyzed by the Superpave design method.The analysis results show that with asphalt flow rate increase,the lubricating effect of the asphalt increases,and mixture com-pactability increases.In the case of reducing aggregate and increasing fine aggregate in middle part,the inter-nal friction resistance formed by skeleton can achieve the compaction effct under low amount of asphalt during construction period,which reducing equipment energy consume during construction period.The energy char-acteristic parameters show that internal friction resistance of the skeleton is highlighted after compaction a-chieves expected compaction effect,which can bear more traffic loads.The comprehensive comparative analy-sis of compaction curve slope and energy characteristic parameters shows that energy characteristic indexes characterize the compaction characteristics of the dense aggregate asphalt mixtures more reasonably than that of curve slope.