基于汉堡车辙试验的沥青混合料性能诊断性分析与评价

Diagnostic analysis and evaluation of asphalt mixture performance based on Hamburg wheel tracking device test

为科学评价沥青混合料的高温抗车辙性能和水稳定性,进行汉堡车辙(Hamburg wheel tracking device,HWTD)试验,采用外观评价法、轮迹曲线评价法和变形曲线评价法3种诊断评价法,评价和统计分析多种沥青玛蹄脂碎石混合料(stone matrix asphalt,SMA)和密级配热拌沥青混合料(asphalt concrete,AC)进行HWTD试验后的芯样状态和结果。结果表明:采用外观评价法可客观反映芯样受轮碾破坏形态,对芯样损坏原因进行定性分析,宏观判断沥青混合料性能;采用轮迹曲线评价法可根据试件受压面的离散状态准确选取有效变形点位,进行变形曲线分析;采用变形曲线评价法可计算沥青混合料的最大车辙深度和剥落拐点,定量评价沥青混合料高温抗车辙性能和抗水损害性能;以蠕变阶段和剥落阶段的变形评价沥青混合料高温抗车辙性能更具可信度和准确性,可将其作为主要评价指标定量评价沥青混合料性能;计算剥落拐点受人为因素干扰极大,可将其作为辅助指标评价沥青混合料的抗水损害性能。

The Hamburg wheel tracking device(HWTD) test is used to scientifically evaluate the high temperature rutting resistance and water stability of asphalt mixture.Three diagnostic evaluation methods,including visual evaluation,track curve evaluation,and deformation curve evaluation,are employed to assess the core sample state and results of stone matrix asphalt(SMA) and asphalt concrete(AC) mixture after HWTD test.Results indicate that visual evaluation method objectively reflects core sample damage caused by wheel loading,qualitatively analyzes the reasons for core sample damage,and macroscopically assesses asphalt mixture performance.Track curve evaluation method accurately selects effective deformation points based on the discrete state of the loaded surface of the specimen for deformation curve analysis.Deformation curve evaluation method calculates the maximum rut depth and stripping inflection points of the asphalt mixture,quantitatively evaluating high temperature rutting resistance and water damage resistance.Evaluating asphalt mixture high temperature rutting resistance based on the creep stage and stripping stage is more reliable and accurate,serving as the main quantitative evaluation index for asphalt mixture performance.Calculation of stripping inflection points is greatly influenced by human factors,making it a supplementary index for evaluating the water damage resistance of asphalt mixture.