Accelerated laboratory pavement model test on cemented base and clay subgrade

A pavement model test box (PMTB) can be used to study the behavior of pavement materials in a laboratory environment that is close as possible to those occurring in the actual pavement. This paper presents a new laboratory PMTB test setup with extensive instrumentations to measure soil deformations and strains and investigates the suitability of the PMTB for determining fatigue, stiffness modulus, and permanent deformation properties of a pavement structure. The tested pavement structure was constructed with a cementitiously stabilized granular base layer of 250 mm thickness with 1.5 % general blend cement-fly ash and a clay subgrade layer of 330 mm thickness. The cyclic load testing was continued at a frequency of 3 Hz up to 8 millions load cycles and measured horizontal tensile strain at the bottom of the stabilized base layer was used to determine the fatigue life of the stabilized layer. The findings indicate that, by measuring the vertical deformations and different depth levels and the horizontal tensile strain at the bottom of the stabilized layer with the instruments used in this study, stiffness moduli of the granular base material and subgrade material can be determined reliably from PMTB testing.