ABSTRACT
Figure 2 shows the load displacement graph for the centre point of the beams. As expected the beams with only LWAC and no confinement experience very brittle behaviour after reaching load at spalling, i.e. no post-peak deformability. The spalling load is identified as the peak load when horizontal cracking in the compression zone occurs, followed by spalling of the concrete cover. The responses for the beams demonstrate the strong influence of the different confinement configurations on the behaviour. In the beams with fibres, transverse reinforcement or a combination of those two, the responses of the beams are very ductile. The peak load is at the same load level for all beams. Strain measurements confirmed the confinement effects where large compressive strains were observed before reaching the ultimate load. The tensile reinforcement remained in the elastic range before spalling but reached yield strain as the ductility increased. Beams with shear reinforcement but no fibres, show a very clear unloading after the first peak load, associated with spalling of the concrete cover in the compression zone. However, the shear links are able to maintain a cross-section and after some redistribution of stresses a second peak point can be identified.
