Dowel Bar and Slab Size Recommendations Based on the Mechanistic-Empirical Pavement Design Guide

This paper provides guidelines on two major concrete pavement design features: dowel bars and slab size. The analysis of dowel bars focused on low volume roads and streets (LVRS), whereas heavier loaded pavements were considered for the analysis of slab size effect. Design charts are recommended based on the newly released NCHRP 1-37A Mechanistic-Empirical Pavement Design Guide (M-E PDG). The dowel design charts allow the user to determine if dowel bars are necessary for LVRS, based on four climatic regions, two base erodibility indexes, and the selected slab thickness. In this analysis, the number of one-way average annual daily truck traffic (AADTT) was limited to 100. In contrast, the analysis of slab size was presented for traffic levels up to AADTT of 7,000 and slab thickness up to 40.6 cm (16 in). In addition, two climatic conditions (dry and wet) were analyzed. Dowel and slab size performance data also are presented. The slab size performance data are based on numerous existing studies in the literature. Although the amount of studies on dowel performance is not as extensive as slab-size effect studies, some very informative studies have been conducted especially on dowel bar misalignment. Dowel bar misalignment tolerances for LVRS are suggested based on these studies.