Evaluating base widening methods

Pavement widening can increase roadway capacity and improve safety, but results in a longitudinal joint between the existing and widened section that is susceptible to longitudinal pavement cracking. Previous research on construction methods focused on the pavement layer but this research looks at the effects of joint type on the base layer. Two base widening joint types, vertical and tapered, are commonly implemented by the Wyoming Department of Transportation. The objective of this study is to determine the most suitable base widening technique for durable pavement sections resistant to longitudinal cracking along the joint line. Field and laboratory evaluations were carried out on 28 existing pavement widening projects to determine the strength of the base layer as well as the occurrence and severity of longitudinal cracking. Results indicate that the tapered joint type has better strength in terms of the Dynamic Cone Penetrometer and Falling Weight Deflectometer analyses, less longitudinal cracking, and lower cost.