Experiences with Dowel Bar Retrofit in California

The technique of Dowel Bar Retrofit (DBR) consists of the installation of dowel bars in concrete pavements originally built without them. This technique is relevant to California because the vast majority of jointed concrete pavements in the state were built without dowel bars, and these pavements are therefore at risk of developing or have already developed step faulting. Many state highway agencies in the United States have tried retrofitting dowel bars into joints and transverse cracks in their concrete pavements, and many have found that DBR extends the life of undowelled pavements by eliminating faulting. Industry records show that more than five million dowel bars have been used in DBR in more than 200 projects in at least 23 states. Information gathered from ten state agencies in the United States revealed positive and negative experiences with DBR. Mixed results have also been experienced in California, however, this paper focuses on the performance from three sites subjected to different climate and traffic loading conditions. These sites have seen excellent performance from the use of different types of dowel bars. The article also briefly mentions other DBR experiences in California.