Impacto da inércia de seções retangulares e do consumo de fibras na resposta estrutural de vigas contínuas em CRFA solicitadas por carga distribuída: campanha experimental

Abstract

In order to play up the proper selection of rectangular section inertia on flexural design of steel fibre reinforced concrete beams, SFRC beams, an experimental campaign has been introduced. Presently, four beams have been tested, where the reference one, with cross section of 150x300 mm2, was in reinforced concrete, RC, and three beams were in SFRC. The rectangular section inertia judgment was on SFRC beams only, where their cross-sections varied in 150x300, 110x400 and 90x500 mm2. The cross-section areas of those beams were constants and their fibre contents were 75, 60 and 45 kg/m3 on concrete volume, respectively. Under those circumstances, the conventional reinforcement arrangements, i.e., steel rebar details, were alternated as well as suppressions were also executed on SFRC beams. Nevertheless, all SFRC beams have carried the reference strength, which meant, the RC beam strength. In addition, it is worth mentioning that all questions called before were carried on continuous beams, where normal and transverse stresses are concomitantly relevant, under uniformly distributed loading. As a conclusion, the results have shown the effectiveness of steel fibres, as a reinforcement alternative, and the advantages of a proper inertia in design issues, warranting the reference strength, even using less reinforcement, both rebars and fibres. Now, concerning to design guidelines, MC10 (2013) proposals have been handled. Herein, applying those letters of support, an interactive methodology was introduced to figure out the flexural strength of RC and SFRC beams, taking, at the same time, all description of reinforcement influence, longitudinal/transverse rebars and fibres. To conclude, in order to improve, in the future, the design of continuous beams uniformly distributed loading, some advices have also been announced.