Effect of Dowel Bar Embedment Length on Joint Load Transfer Efficiency of MnROAD Concrete Pavement Test Cells

It is well understood that for heavily loaded concrete pavements, the use of dowel bars across transverse joints can significantly improve their performance. To function effectively, dowel bars must be properly aligned and have sufficient embedment length to transfer load to the surrounding concrete. The use of new high accuracy dowel bar location equipment has brought renewed interest toward understanding reasonable construction tolerances for dowel bar alignment. The thirteen-year history of pavement performance data from the Minnesota Road Research (MnROAD) facility provides a unique opportunity to examine the effects of dowel bar alignment on joint performance. Specifically, this study investigated the effects of dowel bar embedment length on joint load transfer efficiency. Results of the analysis show that most test cells demonstrate little effect on the overall level and variability of LTE from dowel embedment lengths as low as 10 cm (4 in). Findings of this study could lead to important changes in construction specifications for dowel bar embedment length.