Navegando por Assunto "Design guideline"

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Eficácia da ABNT NBR 6118 (2014) na previsão da carga última de pilares curtos/esbeltos em concreto armado sujeito à flexão composta normal.
(Universidade Federal do Pará, 2019-11-27) LEITE, Jonas dos Santos; MORAES NETO, Bernardo Nunes de; http://lattes.cnpq.br/5790058515094077
Once the short/slender reinforced concrete columns theory has been slightly presented in the national technical/scientific literature, it could be considered as a research goal working up this kind of publication. However, bringing about the accuracy judgment of the ABNT NBR 6118 (2014) design guidelines to predict the load-carrying capacity for short/slender reinforced concrete columns under combined axial load and bending has been the outstanding inquiry target. Wherefore, both the simplest proposals as well as the accurate one have been introduced and taken stock herein. It is worth underscore that two concepts have marked the simplest proposals, namely, standard-column methods with approximate curvature (AC method) and approximate stiffness (AS method). Thus, the interaction diagram concepts together with load-moment curves (P-M), which were addressed in a linear (L) and nonlinear (NL, geometrical issue) way, had accounted for the accurate method. To vouch for the scrutiny undertook before, 17 experimental investigations, which had added up to 320 reinforced concrete columns, composed the database (DB) handled currently. From then on, the performance index ξ has been embraced and assessed by means of descriptive statistic thought, where ξ = Pexp/Ptheo (Pexp = experimental failure load recorded in the DB and Ptheo = theoretical/predicted failure load). Ended up the quest, the effectiveness of whole design guidelines to predict the failure load for short/slender reinforced concrete columns from DB was bearing out by the results had brought forth herein. Notwithstanding the previous positive outcome, it was also pointed out that predicting the failure load of slender columns with slenderness ratio high than 35 the P-M (L) proposal had been in an unsafe condition.
Acesso aberto (Open Access)
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
(Universidade Federal do Pará, 2023-01-25) MONTEIRO, Paulo André dos Santos; MORAES NETO, Bernardo Nunes de; http://lattes.cnpq.br/5790058515094077
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.