Comparison of Pavement Layer Responses Between HMA/PCC Pavement Designs with Heavy Vehicle Loads Using RPAS

The rapid energy sector development and the strong increase in vehicle axle loads has resulted in premature failure of asphalt pavements and, as a consequence, concrete pavements are being considered. However, current design methods assume the significantly heavier vehicle loads will have an elastic impact on the pavement layers and has led pavement engineers to thicken the concrete layer to withstand the heavy loads resulting in a more costly option compared to an asphalt pavement design. Moreover, the current design procedure of concrete pavements discretize the supporting layers using the Winkler foundation model, which makes it incapable of properly considering the impact that heavier truck loads have on the foundation layers. For this reason, researchers at the University of Texas at El Paso (UTEP) developed the Rigid Pavement Analysis System (RPAS), a finite element analysis program that has the capabilities of modeling the foundation layers using a 3-D foundation model, which considers the additive impact of adjacent wheel loads in the subgrade. RPAS has linear elastic theory capabilities and can also be used for the analysis of asphalt pavements when considering the appropriate material properties. This paper presents a comparison study conducted for the Texas Department of Transportation (TxDOT), Odessa District, between a hot mix asphalt (HMA) pavement design and a Portland cement concrete (PCC) pavement design to evaluate the effects that heavy loads have on each pavement layer responses (stresses and strains). The results determined that the PCC pavement provided adequate concrete stresses and significantly reduced the subgrade strains.