Comportamiento a esfuerzo cortante de vigas prefabricadas pretensadas de hormigón autocompactable de alta resistencia

Shear behaviour precast prestressed high strength self compacting concrete beams

In this paper, results of a comprehensive experimental research on shear behaviour of precast prestressed I-beams made with high strength self compacting concrete are presented. In addition to the type of concrete, the influence of the existence of transversal shear reinforcement, of the amount of longitudinal web reinforcement and the prestress level were studied. Experimental results were compared with those obtained by using the expressions of several concrete codes, such as Eurocode 2, ACI and the Spanish Concrete Code EHE, and with the results of the MCFT. The results obtained from the study showed that there is a reduction in shear capacity for beams made with self compacting concrete of about 12 % in comparison with beams made with conventional vibrated concrete having the same compressive strength. All codes predictions used for conventional vibrated concrete were clearly conservative in its estimation of the ultimate shear strength for all beams specimens. Therefore it is concluded that they may be safely used for design of beams made with self compacting concrete.