High Performance Fibre Reinforced Concrete for Double-Tee Beams

Abstract

<p>Modern admixtures as well as the addition of fibers allow producing concrete with extraordinary properties. With such high performance concrete it is now possible to establish structural elements perfectly adapted to practical requirements.</p><p>Precast prestressed double-tee beams allow building large industrial or commercial floors and parking decks in a fast and economic way. These double-tee beams are highly prestressed by bonded strands and contain only a reduced steel reinforcement. A certain problem thus arises in the design for shear resistance; according to national and international codes, the webs must contain a minimum shear reinforcement (stirrups) for which the laying interferes with production. The opportunity to replace these stirrups by a high performance concrete reinforced, if necessary, by steel fibers therefore seems attractive.</p><p>The University of Applied Sciences (UAS), Fribourg, carried out theoretical and experimental research on full-scale concrete double-tee beams in order to analyze the interaction between the quality of concrete, the addition of fibers and prestressing on flexural behavior and shear resistance.</p>