Performance of Bonded Bridge Deck Overlays in Alabama

Abstract

Bridge deck rehabilitation via overlaying has been widely used in colder regions of the U.S., 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 of 2000. The service life performance of the Alabama Department of Transportation's 19 bonded bridge deck overlays to date are as follows: 1) thin (6.4 mm or 1/4 in.) urethane polymer concrete (4 overlays) provided a service life of 3 years and left much to be desired before the 3 years; 2) thin (9.5 mm or 3/8 in.) polyester polymer concrete (12 overlays) has provided highly variable performance (4 of the overlays had service lives of less than 1 year, and the remaining 7 overlays are approximately 10 years old and continue in service; however, most are near the end of their service life); 3) thin (9.5 mm or 3/8 in.) epoxy co-polymer concrete (Flexogrid-2 overlays) has given excellent performance (both overlays are 8 years old, located on I-20 bridges, and remain in excellent condition); and 4) thin (12.7-19.1 mm or 1/2-3/4 in.) asphaltic based NOVACHIP (1 overlay) has been in service for 3 years (during this short period, it has and continues to perform in an excellent manner).