1373676 - Investigating Performance of Cold In-Place Recycled Asphalt Sections in Accelerated Pavement Testing Using Finite Element Modeling

Compared with the laboratory testing, the full scale accelerated pavement testing (APT) can provide results that are more representatives of field conditions. However, APT is expensive, time-consuming, and limited to test the pavement structures and properties. The numerical modeling can reduce the efforts for construction of pavement sections and instrumentation. This study numerically investigated the responses of cold in-place recycled (CIR) asphalt sections under moving aircraft and truck loadings. A 3D finite element (FE) model was built for an instrumented pavement section with a 25 mm high-performance thin-overlay (HPTO) layer, a 71 mm CIR layer, a 13 mm hot mix asphalt layer, a 406 mm base layer, a 305 mm compacted soil layer and subgrade layer. To determine the appropriate mesh size and model dimension, simulation results generated from elastic model were compared with predications obtained from BAKFAA and KENPAVE software tools. Then, the linear viscoelastic model was used to capture the deformation of the surface asphalt layer, with its Prony series parameters determined from experimental dynamic complex modulus tests. The nonuniform distribution and temporospatial variation of tire contact stresses was accounted for in the simulation. Good agreements were achieved between the calculated pavement responses (vertical and horizontal strains) at various locations and the measured responses from field accelerated pavement testing. This study is expected to provide useful suggestions for innovative pavement design under aircraft or truck loading conditions.