High-performance fiber-reinforced concrete in a bridge deck

The purpose of this research was to compare the performance of high-performance fiber-reinforced concrete (FRC) with that of conventional concrete in a bridge deck. FRC is expected to increase toughness, provide enhanced residual strength, and minimize the occurrence and width of cracking in bridge decks. This report describes the development and testing of concrete mixtures containing synthetic fibers in the laboratory and the plant and the placement in the deck of the bridge carrying Route 11 over the Maury River in Lexington, Virginia. The deck was on steel beams. FRC was placed over one of the four piers. Comparisons with the control section without the fibers over a 5-year period indicated that FRC has fewer and narrower cracks, even though higher shrinkage occurred in the FRC specimens. Evaluation of fibers in continuous decks, especially over steel beams, should continue. However, particular attention must be devoted to mixture proportioning, slump, and air content. Further, the workability lost by the addition of fibers should be regained by the addition of a high-range water-reducing admixture, not water, or durability may decrease. Fibers can control cracking and minimize corrosion of the reinforcement in the concrete, thus extending the service life of the structure and reducing maintenance costs, leading to substantial savings.