Evaluación de la eficiencia de soluciones de refuerzo en estructuras de hormigón mediante análisis no lineal evolutivo

Abstract

When designing a structural strengthening solution, the influence of the previous state of the structure on the capacity of the strengthened structure must be evaluated. In addition, strengthening interventions may involve operations such as partial unloading of the structure, placement and removal of temporary shores, application of loads or pre-deformations, restoring of damaged reinforcement or spalled concrete or constraining of lateral strains. Therefore, changes in the cross-section geometry and reinforcement, longitudinal scheme, support conditions, loads and state of stresses and strains, may take place. Furthermore, occurrence of phenomena producing a premature failure or a change in the failure mode, should be avoided. In order to account for such a large variety of causes and phenomena affecting the structural response, a nonlinear and time-dependent analysis model of 3D reinforced and prestressed concrete frames, capable of capturing different failure modes and taking into account the structural history, is described. The model has been verified with tests on strengthened structures available in the literature and has been applied to an actually remodeled structure, comparing the advantages and disadvantages of two different strengthening proposals, showing its capabilities to assess the efficiency of structural strengthening systems..