Effect of PCC Shoulders on Adjacent Concrete Lanes

Abstract

A structural evaluation of the Portland Cement Concrete (PCC) shoulder‐traffic lane longitudinal joint has been conducted. The influence of major design variables of PCC shoulder on the adjacent traffic lane through tying the common longitudinal joint together with an effective tying system was determined by using a finite element analysis program and data from field surveys of several concrete pavements with and without PCC shoulders. The major design variables studied include traffic lane‐shoulder tie, systems and load transfer efficiency, shoulder thickness, shoulder width, and tapering of PCC shoulder. Results of analytical and field studies show that the majority of these variables can have a significant effect on the performance of traffic lane. A minimum load transfer efficiency of 50%, attained through a combination of aggregate interlock and use of steel bars across the longitudinal joint will achieve the greatest structural benefits for the traffic lane as well as the shoulder. Shoulder width should be at least 3 ft‐5 ft (0.9 m–1.5 m) to contribute a significant structural benefit. PCC shoulder thickness as well as tapering the shoulder will only have a small effect on the structural behavior of the adjacent traffic lane when the two slabs are tied together.