Development of the Miniaturized Pressuremeter Test to Evaluate Unbound Pavement Layers

The development of a reliable field test that can be utilized to determine in situ pavement characteristics is discussed in this work. The developed device, which is a modified version of the PENCEL pressuremeter has a 6-in. inflatable probe capable of measuring field stress-strain response of the soils without worrying about edge effects of thin unbound granular layers. A roadway project was selected to conduct some preliminary field measurements in its subgrade layer. The PENCEL pressuremeter (PPMT) along with the miniaturized pressuremeter (MPMT) were used during the testing program to check the performance of the new device, and to validate its results. The results indicated that strength and stiffness properties of poorly graded sand subgrade, measured from running the miniaturized pressuremeter, compare well with those measured from the PENCEL pressuremeter. The MPMTdata can be employed as essential inputs to evaluate existing pavement structures as part of a pavement-management system, and as critical inputs in empirical design methods of new flexible pavements and/or pavement overlays.