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采用振动成型设备以压实度为指标确定了泡沫沥青冷再生混合料振动成型的振动时间。振动成型、静压成型、马歇尔成型及旋转压实成型试件在总空隙率相同的条件下,对比了不同成型方法混合料的力学强度,分析了强度差异产生的原因。基于CT检测手段,分析了不同成型方法混合料内部空隙分布状态、空隙分形维数、最可几孔径及平均孔径。结果表明:旋转压实的“揉搓作用”显著增大了冷再生混合料的间接拉伸强度,振动成型次之,静压成型与马歇尔成型混合料间接拉伸强度(ITS)较接近,而四种成型方法混合料的无侧限抗压强度差别不大;旋转压实及振动成型会影响泡沫沥青冷再生混合料内部细颗粒的分布,进而影响混合料内部空隙的分布状态,这两种成型方式混合料内部空隙数目多且等效半径小。不同压实方法的压实机理的差异导致混合料内部空隙平均孔径、空隙维数及最可几孔径存在差异。空隙特征的不同是引起冷再生混合料力学强度差异的本质原因。
Vibration molding equipment to compaction degree as an indicator to determine the foam asphalt cold recycled mixture vibration molding vibration time. Vibration molding, hydrostatic molding, Marshall molding and rotary compaction molding specimens under the same total void ratio, compared the mechanical strength of different molding methods mixture, analyzed the reason for the difference in strength. Based on the CT detection method, the distribution of internal void, the fractal dimension of voids, the most probable pore size and the average pore size of the mixture were analyzed. The results show that the rotary compaction “rubbing effect ” significantly increases the indirect tensile strength of cold reclaimed composites, the second is vibration forming, and the indirect tensile strength (ITS) of hydrostatic compaction and Marshall molding is closer, However, the unconfined compressive strength of the four molding methods is not different. Rotary compaction and vibration molding can affect the distribution of fine particles in the cold recycled mixture of foam asphalt and thus affect the distribution of void in the mixture A variety of molding methods Mixture number of internal voids and the equivalent radius of small. Differences in compaction mechanism of different compaction methods lead to differences in the average pore size, the voids dimension and the most probable pore size of the mixture. The difference of void characteristics is the essential reason for the difference of mechanical strength of cold recycled mixture.