Acumulación no lineal del daño en el hormigón sometido a cargas alternadas de tracción

Non linear damage accumulation in concrete subjected to alternating tensile loading

Although concrete is mostly used because of its properties under compressive loading, a knowledge of its tensile behavior is necessary in situations in which cracking, and the induced change in stiffness, are critical for the service and ultimate life of the structure. One important aspect of the tensile behavior of concrete is its performance under cyclic loading .The majority of past studies on the tensile fatigue performance of concrete have focused on the behavior under constant aplitude loads. However, in recent years, the effect of variable amplitude loading has also been emphasized. In this work a model is developed for fatigue damage accumulation for concrete subjected to non-constant tensile cyclic loads. The model is based on concepts of Continuum Damage Mechanics and is able to account for the nonlinear propagation and accumulation of damage. Calibration of the model is done using existing experimental data, and its validity is checked against recently published tests. Indications on the use of the model for concrete pavement analysis are also given.