MODELING DAMAGE TO RIGID PAVEMENTS CAUSED BY SUBGRADE PUMPING

The efficient utilization of construction and maintenance resources re quires the ability to effectively predict and model subgrade pumping i n rigid concrete pavements. A review of the evolution of a rigid pavem ent pumping model is presented in this paper, Extensions were made to an existing model to consider the effects of climate and drainage cond itions, as well as soil composition on pumping magnitudes. Additional modifications permit the effect of nonconventional vehicle configurati ons to be considered in the calculation of pumping values. Finally, th e process of calculating pumping volumes and distributing void areas w as altered to provide a more realistic effect. This improved model all ows proposed designs to be analyzed to determine optimum pavement char acteristics. The model is implemented in a finite-element-based method for analysis of pavements that also includes the effects of concrete cracking and fatigue. Urgent need for experimental data on the size an d growth of voids beneath a pavement slab is pointed out.