Comparison of Stress Fields near Longitudinal Construction Joints of Tied and Doweled Sections in Portland Cement Concrete Pavements

Geuntae Hong,Seongcheol Choi,Jung Heum Yeon,Moon Won,Jiyoung Kim

doi:10.3390/su132011217

Abstract

In Portland cement concrete (PCC) pavements, tie bars are commonly used at longitudinal construction joints (LCJs) to prevent the lanes from separating. Meanwhile, the increase in multiple lanes due to greater traffic volumes has raised concerns about potential longitudinal cracking; this has led to the use of dowel bars instead of tie bars at LCJs. However, there is a paucity of studies focused on the comparison between the behaviors of concrete pavement based on the restrained conditions provided by tie and dowel bars at LCJs. In this study, we investigated the effects of the placement of tie and dowel bars at LCJs on the potential for longitudinal cracking in response to the increase in concrete stress that may occur when the lanes are tied together in PCC pavements. Field testing verified that the variation in concrete strain was more restrained in the case of a tie bar than a dowel bar, whereas it resulted in higher stress in the concrete element in the tie bar section. However, the use of dowel bars caused more movement in the transverse direction at LCJs as compared with tie bars. Thus, our results indicate that using dowel bars reduces the potential for longitudinal cracking; however, it may increase the potential for lane separation.

Highlights

The concrete strain was measured through concrete placement, only a portion of the data is shown because it represents the overall trend of variation in the entire monitoring period
Given the same variation in temperature, the variation in strain in the dowel bar section was greater than that in the tie bar section. This indicates that the movement of the measured concrete elements was more strongly restrained by the tie bar than the dowel bar, which agrees with the current practice
This study investigated the effects of the placement of tie and dowel bars in longitudinal construction joints (LCJs) on the stress development in concrete in a Portland cement concrete (PCC) pavement

Summary

Introduction

Tie bars have been used at longitudinal construction joints (LCJs) in Portland cement concrete (PCC) pavements to keep lanes from separating and, to a lesser extent, to provide enhanced load transfer efficiency between lanes or between an outside/inside lane and a tied shoulder [1]. Dowel bars have traditionally been used nearly exclusively at transverse contraction joints in jointed plain concrete pavements (JPCPs) to transfer load from one slab to the [2]. Because the actions of tie and dowels bars are remarkably different, their design methods are vastly different. Tie bars are designed based on subgrade drag theory (SGDT), which was developed several decades ago, whereas the design of dowels is primarily based on the work by Timoshenko, expanded later by Friberg and Bradbury [2]

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