Gaceta Técnica

9-21

Authors: María Fabiana Muñoz, María Elena Perdomo, Ricardo Picón

In this work, an experimental study of low cycling fatigue in reinforced concrete elements with dominant flexural behavior is developed. The reinforced concrete elements are subjected to cycles of displacement until rupture. A total of two bending beams were tested. In each cycle, the degradation of the resistance and rigidity due to the effect of low cycling fatigue is evaluated. Preliminary results and observations are presented and discussed. The tests are relevant to develop an analytical model of non-linear behavior that describes the degradation of strength and rigidity of reinforced concrete structures subjected to severe earthquakes

35-52

Authors: Nelson López, Ronald Ugel, Reyes Indira Herrera

In this research, the nonlinear behavior of a real-scale experimental joint (node) is studied, consisting of three reinforced concrete elements, one column and two beams joined to a structural steel column at the upper level. In the numerical analysis the model of the union was analyzed in the inelastic range, this model was elaborated with the finite element program based on fibers, SeismoStruct to analyze as a function of time, the traction and compression efforts in the confined area and not confined area of the concrete column and in the longitudinal reinforcement steel, as well as verification of the design of the base plate that joins the two columns. The results showed that tensile stresses in the unconfined zone surpassed the concrete breaking point, with cracking occurring just below the lower edge of the beams; in the confined area the traction efforts were much lower, with cracks occurring later than in the non-confined area. The concrete column-steel column joint behaved as a rigid node, so the elastic design was consistent with the calculation methodology of base plates for steel columns.