Deficiencies and problems inherent in existing empirical and mechanistic design procedures have prompted an incremental design approach based primarily on the response of in-situ pavement to nondestructive tests. The first increment is designed with a structural section sufficient to preclude excessive subgrade deformation using conventional pavement design procedures. The second, if necessary, is placed in sufficient thickness to avoid excessive tensile strain of the asphalt concrete surfacing and, thus, premature fatigue cracking. Afield evaluation was conducted on incremental sections with and without fabric reinforcement, and on control sections designed using the standard California (empirical) procedure. On the basis of laboratory tests characterising all elements of the structural section, pavement designs for the site were developed using two empirical and one mechanistic-empirical procedure. These designs were compared to that designed by the incremental procedure. The results revealed that substantial savings in initial structural section costs are possible by incremental pavement design.
Abstract