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为准确掌握摊铺过程中沥青混合料在螺旋分料器中的离析原因及分布规律,基于混合料在螺旋内的运动特性,分析了螺旋作用下混合料颗粒的轴向速度及圆周速度与螺旋半径、节距、转速及摩擦因数之间的关系,并通过现场试验给出了混合料离析在螺旋中的分布规律。结果表明:沥青混合料在螺旋作用下产生的离析主要受螺旋结构和运动参数的影响;随着螺旋半径的增大,混合料的轴向速度单调递增,圆周速度先增大后减小,并在螺旋主要工作区(螺旋半径14～20cm)圆周速度与轴向速度较为接近,能够通过改变螺旋转速、螺旋与混合料的相对位置来调整混合料的运动特性,限制混合料颗粒的离析;螺旋上部的沥青含量比其底部高出2%,螺旋中部的沥青含量比两侧高出0.7%,沥青混合料级配均值在其规定的范围内,但螺旋上部的混合料规格偏细;采用混合料满埋螺旋的方法,可解决螺旋悬挂处沥青含量的离析,但不能解决螺旋上下处的离析。
In order to accurately understand the segregation reason and distribution regularity of asphalt mixture in the spiral distributor during paving, based on the movement characteristics of the mixture in the helix, the influences of the axial velocity and the peripheral velocity of the mixture particles on the helix Radius, pitch, rotation speed and friction coefficient, and the distribution of the mixture segregation in the spiral was given through field experiments. The results show that the segregation of asphalt mixture under helical effect is mainly affected by the helical structure and the movement parameters. As the helical radius increases, the axial velocity of the mixture increases monotonously, and the circumferential velocity first increases and then decreases In the spiral main working area (spiral radius 14 ~ 20cm), the circumferential velocity and axial velocity are close to each other, and the movement characteristics of the mixture can be adjusted by changing the relative rotation speed and the relative positions of the helix and the mixture, so as to limit the segregation of the mixture particles; The bitumen content in the upper part is 2% higher than the bottom part, and the bitumen content in the middle part of the spiral is 0.7% higher than that on both sides. The average gradation of the asphalt mixture is within the specified range, but the specification of the mixture in the upper part of the spiral is too thin. Full buried spiral method can be resolved at the helical suspension asphalt content segregation, but can not solve the upper and lower spiral segregation.