Análise da capacidade resistente de pilares de concreto submetidos à flexo-compressão conforme a ABNT NBR 6118:2014 e outras referências normativas

• Autor(a) principal: Gonçalves Junior, Adilson Aparecido
• Data de Publicação: 2016
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da Universidade Estadual de Maringá (RI-UEM)
• Texto Completo: http://repositorio.uem.br:8080/jspui/handle/1/3518
• topic: Pilares de concreto armado, Diagrama tensão-deformação, MATLAB - Brasil; Reinforced concrete columns; Stress-strain diagram; MATLAB; - Brazil; Engenharias; Engenharia Civil

Modern society has more demanding consumer criteria than at other times. Durable construction, architectural design flexibility and wide spans are items of the package of needs. In concrete structures, the development of high strength concrete (HSC) and the refinement of calculation methods are fundamental practices so that these requirements be attended. Encouraged by this scenario, there was a recent movement to update the ABNT NBR 6118:2007, Brazilian Standard that deals with the design procedures for concrete structures. The introduction of HSC in its content was the most significant change that has occurred. It's on this scenario that for this present study was proposed the analysis of the Brazilian Standard criteria applied in determining the loading capacity of HSC columns with rectangular section subjected to combined flexural and axial compressive. For this, it was developed, with the helping of MATLAB R2009a program, a computational program which allows the production of envelopes of bending resistance according with the criteria of the Brazilian Standard and also to the rules of the Eurocode (Eurocode 2 (2002)) and ACI (ACI 318 (2014)). The evaluation of the Brazilian standard was done in two basic ways. In the first case, the results produced by ABNT NBR 6118:2014 were compared with those produced by the others standards. The second part, it was analyzed the results produced by the stress-strain diagram parable-rectangle of the ABNT NBR 6118: 2014 with the results when it was applied the rectangular diagram of the same standard. In general, for the Brazilian Standard it was observed that the growth rate of the resistant capacity is more significant in the conventional concrete group, this being reduced to a much smaller variation in HSC group. Analogous results were observed when it was applied Eurocode 2 (2002). Comparing the two standards, it was noticed that the Brazilian Standard presents more conservatively than the Eurocode for all concrete strength classes. However, when it was considered the "UK National Annex to Eurocode 2 (2002)", then the NBR presented higher resistance values than those were calculated by this standard. Now, the behavior of envelopes of bending resistance obtained by ACI 318 (2014) was very particular. The growth rate of resistance values didn't show big changes of the conventional concrete for the HSC. Comparing the results with the Brazilian Standard, it was noticed, in general, that the NBR is less conservative for concrete classes with lower resistance and more conservative for HSC. Comparing the two stress-strain diagrams of the ABNT NBR 6118: 2014, it was noticed for all cases analyzed that the bending resistance produced by the stress-strain diagram rectangular are greater than those resulted from stress-strain diagram parable-rectangle