Performance of Bonded Bridge Deck Overlays in Alabama

Bridge deck rehabilitation via overlaying has been widely used in the colder regions of the United States but not in Alabama due to a warmer climate and nonuse of deicing salts on bridge decks. However, Alabama does have some experience with bonded deck overlays, and the purpose of this work is to document the performance of the overlays that were placed in Alabama prior to the Summer 2000. The service life performance of the Alabama Department of Transportation’s 19 bonded bridge deck overlays to date are as follows:  • Thin (6.4 mm or 1/4 in.) urethane polymer concrete (four overlays) provided a service life of 3 years and left much to be desired before the 3 years.  • Thin (9.5 mm or 3/8 in.) polyester polymer concrete (12 overlays) has provided highly variable performances. Four of the overlays had service lifes of less than 1 year. The remaining seven overlays are approximately 10 years old and continuing in service; however, most are near the end of their service life.  • Thin (9.5 mm or 3/8 in.) epoxy co-polymer concrete (Flexogrid) (two overlays) has provided excellent performance. Both overlays are 8 years old and located on I-20 bridges and remain in excellent condition.  • Thin (12.7–19.1 mm or 1/2–3/4 in.) asphaltic based NOVACHIP (one overlay) has been in service for 3 years. During this short period, it has and is continuing to perform in an excellent manner.