Development of an Analytical Model to Predict the Field Permeability of Asphalt Pavements

Abstract

Measurement of the field permeability of asphalt pavement is affected by three-dimensional flow, saturation, and other field boundary conditions. Therefore, field permeability testing is generally avoided for compaction quality control, mix evaluation, and evaluation of moisture intrusion or damage of asphalt pavements. Instead, laboratory permeability is used for asphalt mix (compaction) evaluation. Because most transportation agencies and paving contractors collect field cores for compaction and mix quality evaluation, an analytical model to predict field permeability can be useful in the study of the hydraulic conductivity of field pavements. This study used an analytical model to determine the field permeability of asphalt pavement by using laboratory tests for permeability and permeable pores of cores. Permeability and the permeable porosity of two sizes of asphalt cores were determined in the laboratory with a falling head permeameter that was modified with a salt concentration–measuring meter. The parameters were then used in the analytical model to predict field permeability. The predicted values from the model were found to compare reasonably well with the full-scale field permeability values. The results of the analytical model were compared with the results from existing models, and the developed analytical model showed an improvement over the existing models. The model can be a useful tool in the study of the hydraulic behavior of asphalt.