ABSTRACT
Jorun-Marie Hisdal SINTEF Building and Infrastructure, Trondheim, Norway
Giedrius Zirgulis, Elena V. Sarmiento & Terje Kanstad Department of Structural Engineering, the Norwegian University of Science and Technology (NTNU), Trondheim, Norway
ABSTRACT: Within a relatively large Norwegian research programme, denoted COIN (Concrete Innovation Centre) covering a broad range of concrete research topics, fibre reinforced dapped end beams have been tested to study the structural behaviour of fibre concrete in discontinuity regions (D-regions). Ordinary strength concrete with 1% (80 kg/m3) 60 mm long end hooked steel fibres has been used. The shear reinforcement and the splitting tensile reinforcement in the beam ends used in the traditional solution have been partially or fully removed. The typical strut and tie models commonly used in practical design have been modified to include the effect of the fibres. A simplified reinforcement layout to be used for FRC is proposed, and gave similar capacity and ductility as the solution without fibres. Furthermore did the beams with fibres replacing all the transversal and splitting tensile bars, also give reasonable strength and ductility. In the current fibre project flowable concrete generally is preferred, and fibre distribution and orientation, and the influence of the casting process are major topics. Therefore fresh concrete testing has been carried out, and sections are cut and the amounts of fibres recorded and compared to theoretical values.
