Contribution of the eccentricity of unbonded tendons to the punching shear resistance of prestressed flat slabs

Resumo

With the increasing use of prestressed flat slabs in floor construction, studies are needed to assess the
high shear stresses generated in the slab-column connection, which is a vulnerable point to punching failure and
crucial for the design of this constructive system. Together with experimental studies, the use of computational
tools has allowed the analysis of the influence of prestressing on the ultimate resistance and thus the understanding
of the puncture phenomenon through numerical simulations. In this study, experimental tests were simulated
through nonlinear three-dimensional analysis using the computational program ATENA. The nonlinear behavior

of cracked concrete and the yielding of steel in passive and active reinforcement was considered. The load-
displacement and load-strain curves were compared between the experimental and numerical results obtained, with

the aim of validating the constitutive models adopted for concrete and steel. From the adequate calibration of
models, a parametric study was carried out with variations in the spacing and eccentricity of the tendons in the
slab, thus allowing to identify the influence of these parameters on the punching shear resistance.