Results of “pseudo-static” tests with cyclic horizontal load on r.c. panels made with wood-concrete caisson blocks

In recent years, the seismic behaviour of reinforced concrete bearing panels structures has been the object of several research works. This paper presents a summary of the results obtained in a wide experimental/analytical correlation campaign carried out as a joint effort between the Università di Bologna and the EUCENTRE labs in Pavia. This effort was devoted at the assessment of the seismic performances of lightly reinforced concrete bearing panels. The panels are made using leave in place wood-concrete caisson blocks. In order to obtain a correct characterization of seismic behavior (stiffness, strength, ductility) of such panels, a number of tests were performed both upon two dimensional (3.0 m by 3.0 m) panels and upon 6 meter tall H shaped substructure. In the experimental tests a number of horizontal loading cycles were imposed to the structures, while the vertical load was kept constant The results obtained show a good agreement between the experimental data and their analytical counterparts. Also a high (cinematic) ductile behavior of the panel was observed, with vertical re-bars loaded up to yielding (it was never observed a failure in shear). The maximum horizontal load loads applied to the structural systems were found to be always comparable in magnitude (and often wide superior) to the applied vertical loads. All systems tested showed a residual bearing capacity w.r.t. the vertical loads, also when large lateral deformations were developed and the lateral stiffness had undergone substantial reductions. In all test the panels were capable to sustain repeated cycles at maximum deformation.