Small-Scale Accelerated Load Test for Doweled Jointed Plain Concrete Pavement

AUTHORS: Donnelly, C.A.; and Vandenbossche, J.M.

ABSTRACT: Performance of dowel bars in jointed plain concrete pavements (JPCPs) can decrease due to damage accumulation around dowels. This damage is caused by repeated development of high bearing stresses, reducing the joint stiffness. This increases the potential for pumping to occur followed by the progressive development of faulting. The relationship between key design parameters and damage accumulation is not well established. This limits the prediction of long-term dowel performance, especially for alternative dowels. Many agencies are considering the use of alternative dowel bars with a range of diameters and stiffness and therefore need to evaluate the performance of these dowels to justify increased costs. In this study, a novel laboratory test setup was developed to characterize damage development around the dowels caused by repeated vehicle loads. The beam test was designed to replicate the stress state along the dowel present in a fullscale slab loaded adjacent to the transverse joint. A range of key parameters such as dowel diameter, dowel material, pavement thickness, and load magnitude can be tested with a lower cost and effort compared to full-scale slab testing. Beam specimens are subjected to repeated vehicle loads which damage the concrete surrounding the dowel. Deflection measurements made along the surface of the beams are used to quantify the reduction in dowel performance caused by damage around the dowel. This laboratory test will be used to evaluate a range of dowels and will enable an accurate estimation of the long-term performance of dowels. This will be particularly advantageous for agencies interested in implementing alternative dowels for long life paving projects.