Ensaios de pórticos planos de concreto armado com pilares esbeltos

Abstract

In this work it is presented the results of a experimental research on the behaviour of reinforced concrete plane frames with slender columns up to rupture. Eight frames were tested. They had pinned supports and were formed by two columns and one beam with constant rectangular cross-section. Load was applied on one of the columns with an eccentricity of three centimeters with respect to its axis. In these frames the length of the columns and the height of the beams were varied. Graphs were done relating the load to the measurements taken (horizontal displacement of the loading point, rotation at the supports and strains in the materiais) in order to characterize the behaviour of the frames during the tests. The values of the horizontal displacement of the loading point measured were compared with predicted values given by a computer programme (8,10). The maximum loads carried were also compared with the values obtained from the model-column method presented in the CEB-FIP code (3,4). In the first comparison it was noticed some divergence, but in the latter a good agreement was obtained between experimental and theoretical results. In all the frames the failure occurred due to instability (buckling).