Design and performance of fiber-reinforced concrete with adapted rheology for construction and repair of bridge structures

“The objective of this document is to design high-performance fiber-reinforced self-consolidating concrete (FR-SCC) for infrastructure repair and fiber-reinforced super-workable concrete (FR-SWC) for bridge construction. The investigated fibers included propylene synthetic fibers, hooked steel fibers, double and triple hooked steel fibers, hybrid crimped steel fiber and polypropylene multifilament fibers, and micro-macro steel fibers. The fiber volume varied between 0 and 0.75%. An expansive agent (EA) was incorporated to compensate for shrinkage and induce compression in the concrete at early age. Two types of EA (G and K) were employed at 0 to 8%, by mass of binder. The investigated FRSCC and FR-SWC mixtures achieved excellent passing ability and stability. Compared to non-fibrous mixtures, the optimized mixtures exhibited 30% and 110% increase in compressive and splitting tensile strengths, respectively, and developed high toughness. The combined use of EA and fibers led to a synergetic effect of increasing the resistance to restrained shrinkage cracking. Low cracking potential was observed for mixtures made with steel fibers combined with EA compared to high cracking potential in case of nonfibrous SCC. The optimized FR-SWC mixture, with some adjustments to reduce fluidity, was successfully used for the re-decking of a bridge in Missouri. The concrete exhibited high workability and was easily pumped, consolidated, and finished. After 18 months, no signs of cracking were observed in the deck, except for hairline cracks near the intermediate bent. The high-performance fibrous concrete can provide cost saving of up to 55% in areas with high traffic volume but limited savings in the low traffic volume areas”--Abstract, page iii