Two sessions on "Performance of Overlays of Polymer Concretes" sponsored by Committee 548 on Polymers in Concrete were held at the Spring Convention in Denver, Colorado in March 1995. Five papers were presented at the first session titled: "Performance of Polymer Concrete Overlays Part I: Over 10 Years", and six papers were presented at the second session titled: "Performance of Polymer Concrete Overlays Part II: Less than 10 Years Old". All eleven papers published in this volume are case studies. Since different types of overlays-including thin overlays, polymer, epoxy and sulfur concrete are successfully in service on bridge decks, highways and garages, these authors feel that it is important to share their knowledge with the readers of this publication.