Study of time-dependent effects in craked sections using the multilayer model

Abstract

This paper summarizes the principal results of a thesis whose objective is to set up a model for the service analysis of concrete structures, accounting for delayed effects of creep and self-induced and superimposed deformations. The multilayer model is developed assuming the Navier Law wich relates the analysis at a "cross-section level" with the global analysis at a "structure level". The multilayer model permits to take into account cracking at a "cross-section level", although the assumption of vertical cracking restricts its application to beams in bending. The tension-stiffening effect is considered in a general step-by-step analysis, establishing the self-stress equilibrium in every time interval. This method of analysis may be classified among stress relaxation procedures, from which follows the implementation of a model, that has been checked at a sec-tion level, at a structure level and compared with creep tests.