Análise da deformação lenta em vigas de concreto protendido

Abstract

This work consists on a analysis of time dependent strain on prestressed beans using the software MATLAB in order to compare the values of short and long term strain, verifyng the coefficient that is suggested by brazilian code, ABNT NBR 6118:2014, to simulate those timedependent behaviours. Also, this work made a analysis on the effect of shrinkage on long term strain in some of those prestressed beans. Looking foward to the complexity in obtaining precise and trustable methods for evaluate the time dependent strain, allied to the low priority that is still given by some of the structural engineers on precise undestanding of creep and shrinkage strain on time dependent behaviour of prestressed beans and the use of empirical coefficients to estimate the long term deformation of those beans, this paper compares the short and long term strain using the coefficient of 2,5 that structural engineers and softwares of structural analysis uses on Brazil to simulate the time dependent strain multiplying the immediate strain. Starting on a initial model of prestressed beam suggested by Chen (2008) of a hiperestatic bean, and a model of an isostatic been given by Hepta Engenharia, an structural engineering office, both models was made using the software developed by Laboratório de Mecânica Computacional e Visualização (LMCV), on the Structural Department of Federal University of Ceará (UFC), the beams were analised in order to obtain immediate and long term displacements and compare them with the coefficient.