Experimental Research on Interlayer Strain Transfer of Semirigid Asphalt Pavement and Influencing Factors

Interlayer strain transferring effect of homogeneous or heterogeneous materials is obtained by small-scale interlayer bonding test model to quantitatively evaluate the interlayer bonding of semi-rigid asphalt pavement. The influencing factors are also analyzed. Results show that interlayer strain transferring effect between homogeneous materials is strong. The interlayer contacting is continuous, while the interlayer contacting between heterogeneous materials is discontinuous. Interlayer contacting can be assumed continuous in the structure calculation of homogeneous materials, while Goodman model is recommended for heterogeneous materials. Temperature and load level significantly influence strain transfer between layers. Specifically, with the increase in temperature, interlayer strain value and strain differences of homogeneous or heterogeneous materials become large, and interlayer strain transferring effect becomes poor. As the load level increases, strain transferring effect between homogeneous materials is gradually weakened and not conducive to the combination of interlayer. Meanwhile, strain transferring effects between heterogeneous materials are improved, and cooperation deformation of upper and lower materials occurs easily under compressive stress. Interlayer contacting can be assumed continuous between asphalt or semi-rigid material layers in the structure calculation to ensure that the theoretical model corresponds to the practical situation, while the assumption is semi-continuous or semi-sliding between asphalt and semi-rigid material layers.