Analise experimental estática e dinâmica de viga de concreto armardo reforçada com barras externas protendidas

Abstract

Concrete works are present in all economic sectors and it can be said that they still dominate the market. Among other external factors, its resistance and durability characteristics contribute to this diffusion of its use. However, as the use of concrete grows, the new architectural configurations advance, requiring ever more slender models of civil works. This type of configuration entails, among other factors, the decrease of the overall stiffness of the structure, making them more susceptible to vibrations. From the point of view of civil works and works of art already built and that under the action of time and accidental loads (impact loads, seismic, among others) suffer loss of rigidity in global or punctual terms (of its elements), the vibration becomes a danger factor. These vibrations are the effects arising from the dynamic loads to which the structure is being subjected. To evaluate the effects of these actions, structural engineering makes use of dynamic analysis. In the field of dynamic analysis, one of the methods that seeks to evaluate these effects against natural frequencies, vibration modes and damping rates is modal analysis. These parameters are known as modal parameters and are important because they respond to changes in structure stiffness. As regards structure responses to dynamic effects, reinforcement can be an alternative to gain rigidity and increase the useful life of an element that is under a situation of structural danger or environmental incom- patibility. Of the various methods already known and practiced by the market, one has the protension as a very present factor in these works. Despite this, the use of external protonation is not yet so prevalent amid the widespread use of the proton. However, many factors make its use a viable alternative, especially when it comes to reinforcing structures. Thus, in order to introduce the dynamic concepts in the analysis of a structure the present work seeks to evaluate the effects of the external protension in the rigidity and consequently in the dynamic parameters of a beam of reinforced concrete from its intact state until a state of damage in which there is significant loss of rigidity by simulating an overpass beam subjected to an impact of a truck in which part of its concrete structure is removed by obtaining its modal and deformation parameters. Keywords: reinforced concrete; vibrations; stiffness; modal analysis; structural reinforcement