FLEXURAL BEHAVIOR OF REINFORCED, PRESTRESSED AND COMPOSITE SELF-CONSOLIDATING CONCRETE BEAMS

The structural behaviour of reinforced, prestressed self-consolidating concrete beams and of composite steel – self- consolidating concrete beams was investigated. The flexural behaviour at service stage and at ultimate limit state was experimentally studied by means of four-point bending tests on six beams. The experimental program considered two beams for each structural type. The reinforced beams included shear reinforcement, the prestressed beams presented sliding tendons with parabolic layout, while the composite beams consisted in steel profiles embedded in concrete. Only one beam of these latter was provided with shear connectors. The results showed that self-consolidating concrete (SCC) exhibits slightly higher strength with respect to normal vibrated concrete (NVC). Nevertheless, Eurocode 2 predictions related to NVC give good results in terms both of ultimate bending moment and of moment-curvature diagrams. On the contrary, it is not able to correctly predict the crack spacing and the crack width. These can be better described by introducing some amendments to the experimental coefficients of the formula proposed by the considered Code.