Prediction of Spalling and Roughness in the Mechanistic-Empirical Pavement Design Guide

Abstract

This paper documents an assessment of the prediction of joint spalling and International Roughness Index (IRI) for jointed plain concrete pavements (JPCP) in the Mechanistic- Empirical Design Guide (MEPDG) report and software. The role of joint sealant type in the prediction of spalling is examined, as well as the sensitivity of predicted IRI to predicted spalling and other factors. Limitations of the predictive accuracy of the MEDG spalling and IRI models are detailed. Users of the MEPDG and its accompanying software should be aware of the inference space of the data from which these spalling and IRI models were developed, and the practical implications of using the MEPDG models to predict the effect of joint sealant type, joint spalling, climate, and other factors on roughness in jointed plain concrete pavements. The MEPDG software predicts essentially no spalling for joints with preformed sealant, but substantially more spalling – and exactly the same amount of spalling – for unsealed joints, hotpour- sealed joints, and silicone-sealed joints.