Análise dos fatores intervenientes da fissuração de placa de piso de concreto apoiada sobre lajes de concreto armado

The entire structural system must meet the criteria of functionality, quality, service performance, durability and safety. The lack of verification of some of these parameters or the lack of research in this sense have contributed to the emergence of pathological problems in concrete structures. In the last decades, there has been an increase in the quantile of pathological phenomena in concrete floors of works located in Agreste Pernambucano. In order to understand the performance of concrete plates supported on deformable bases under the action of static loads, as well as the parameters that infer in the appearance of pathological problems, the present work had an objective to analyze the main factors that contribute to the cracking and plate breaking in concrete floors supported on elastic, through the numerical analysis. A computer aided tool was used that uses the Finite Element Method for nonlinear analysis, ANSYS®. The variables analyzed were the concentration of stresses at the edges of the plates and the maximum deflections in the elements that make up the entire structure of the concrete floor as a function of the variation of the longitudinal deformation modulus of the concrete and the coefficient of friction in the contact region of the plates. In general, the critical points of the variables were analyzed in order to verify if they contributed to the propagation of cracks and the rupture of the concrete plate. A shear flow problem was verified due to poor adherence in the contact region between plates. It was also verified that the problem of cracking is not related to the resistant moment at the edge of the plate, but to the effect of the warpage. It was found that the massive slab has better structural performance as a sub-base when compared to a ribbed slab, around 40%. In addition, a recommendation was made in order to minimize the shear flow problem in the design step by inserting rigid locking bars into the contact region between the plates.