Bond Properties of High-Strength Fiber Reinforced Concrete

Compact Reinforced Composite (CRC) is a special concept for high performance concretes, where ductility is achieved through incorporation of a large content of short, stiff and strong steel fibers (6 vol.%). This ductility combined with high strength (150-400 MPa) and the ability of the small fibers to provide an effective reinforcement against even small cracks, makes it possible to obtain exceptional bond properties for deformed reinforcing bars. Results show that full anchorage is achieved with an embedment length of only 5-10 diameters for ribbed bars, which has led to applications in buildings, where CRC is used for in-situ cast joints between pre-cast decks - joints which can transfer full moments with a width of 100 mm. This type of joint, which was used for a university building, has been extensively tested for different loading situations and for behavior in a standard fire. As the fiber reinforced matrix provides a strong, ductile joint which responds well to dynamic loads it is expected to perform well under seismic loads.