Efeito do módulo de elasticidade nas perdas de protensão em vigas pós-tensionadas

Abstract

The present work presents a contribution to the study of prestress losses in structural elements of concrete, evaluating the effect of the variation of the modulus of elasticity, according to the coarse aggregate and class of aggressiveness in the concrete prestressed. The prestress loss is present in all elements that make use of this constructive system, being intrinsically linked to the materials that make up the structure. Therefore, prestress losses have a great influence on the final tensioning of the strands and cannot be neglected, and must, therefore, be correctly estimated. In this work, immediate and progressive prestress losses were evaluated in post-tension prestressed beams. Two models were used for prestress loss analysis, a prestressed concrete beam with a straight cable, and another with a parabolic cable, varying their classes of aggressiveness, coarse aggregate used and prestressing day. The prestress losses in beams were higher in parabolic cables compared to beams with straight cables, with the same magnitude of eccentricity in the middle of the span, and when using a higher modulus of elasticity and prestressing age, the total prestress losses decrease.