LAUSR

ABSTRACT The initial full-scale experiment in Costa Rica began in 2012 under a program that has been identified as PaveLab. The main purposes were to identify the effect of typical construction practices in the country: use of granular vs. cement-treated bases (CTB), and thin vs. thick HMA layers. The effect of moisture was also considered: sections under optimal moisture conditions were compared to sections where the water table was raised to approximately the middle of the subbase. The recorded information includes: stress and strain measurements for the top layers of the structure, vertical pressure in supporting layers, surface roughness and deflection data. Preliminary results show the importance of considering the effect of water on the stability of pavement structures. It was noted that even though the CTB layer showed higher initial stiffness as compared to a granular base, the loss of stiffness associated to load-induced damage occurred at a significantly higher rate than that observed at the other layers. Similarly, the results showed that an increase in HMA layer thickness results in higher overall structural capacity, independent of the supporting layers. The data is currently being used to calibrate fatigue, permanent deformation and surface roughness transfer functions.