A New Interlayer Model For The Bending Stress Analysis Of Bi-layer Cement Concrete Pavements

Stress analyses for the bonded and unbound bi-layer cement concrete pavements [BLCP] have been presented in the Specification for Cement Concrete Pavement Design in China. Based on Kirchhhoff’s assumptions, an interlayer model proposed in 2013 by ZHENG, Z-model, is able to study the interlayer transition from bonded and unbound states in BLCP. A new parameter c is introduced in Z-model to characterize the interlayer condition between bonded and unbound conditions. The shift of position of the neutral plane of BCLP is relative to c and is derived in different cases. And bending rigidity is obtained from the formula for neutral plane. This paper also made a comprehensive analysis of the influence of pavement thickness and material properties on the natural plane and bending rigidity of the slab. Finally, using self-programmed Visual Basic program, bending stress distributions were calculated for the BLCP on Winkler’s foundation of different pavement thicknesses and material properties. The results are of reference value to fully understanding of stress distributions in BLCP. This study lays a foundation for the design of BLCP with different interlayer conditions.