Shear behaviour of hybrid composite-concrete beams: Experimental failure and strain analysis

The combination of high performance composites and concrete results in hybrid composite-concrete elements which no longer resemble the traditional reinforced concrete structures. Consequently, these hybrid elements have a different structural behaviour that requires new evaluation procedures. This paper focusses on hybrid TRC-composite-concrete elements which are used as a substitute for reinforced concrete beams within a floor system. Their shear behaviour is experimentally investigated by the examination of ten short-span hybrid beams with different geometries. Visual inspection shows that shear failure occurs by an inclined flexural shear crack in the concrete. A rosette strain gauge analysis proves that the principal strain and stress orientations are in accordance with theoretical predictions. Finally, the small influence of shear deformation on the total deflection of these beams is illustrated.