Effect of joint spacing and pavement thickness on concrete overlay performance

Abstract

Concrete overlays provide cost-effective maintenance and rehabilitation strategies for pavement systems. A database has been developed in Iowa that records the historical performance of overlays based on records of International Roughness Index (IRI) and Pavement Condition Index (PCI) over a 20-year period. Based on these data concrete overlay service life has been modeled for various joint spacings. The data demonstrate that durability and service life can be improved. A review of PCI data indicates that improving construction quality to eliminate premature failure has the potential to add at least 10 years to the service life of PCC overlays. Even though concrete overlay technology is not a new concept, most of its design procedures still follow empirical methods, therefore this study applied AASHTOWare Pavement ME Design (Version 2.3.1) software to identify the effects of design para ms on concrete overlay service life. The theoretical insights provided by Pavement ME Design were compared with historical performance data and used to provide recommendations with respect to optimized joint spacing in overlay pavement structures. Comparison of the historical performance-related data with Pavement ME Design software results indicates that the Pavement ME Design software is conservative in predicting concrete overlay service life.