Kentucky Research: A Flexible Pavement Design and Management System

Various strategies for designing pavement structures are discussed. Initial full-life design, stage designs and planned extensions of service life, final design, surface renewals for deslicking, no-defect designs for high-type high-volume facilities, and allowable-defect designs are considered. Economics enter in terms of salvage value of existing pavements and alternate designs using different proportions of materials within the structure. The elastic model represented in Chevron\u27s n-layered computer program is the basis for theoretical relationships. Ranges of values are given for input variables such as Young\u27s moduli, Poisson\u27s ratio, thicknesses for layers, tire pressure, and load. The Kentucky CBR is related to modulus by E = 1500 x CBR and is correlated with the AASHO Soil Support value and other strength relationships. The modulus of crushed stone base is shown to be a function of the moduli of the asphaltic concrete and sub grade. Appropriate relationships are given