Cálculo da armadura mínima de flexão em vigas de concreto armado: estudo comparativo entre normas

• Autor(a) principal: Bezerra, Filipe Cassiano de Carvalho
• Data de Publicação: 2017
• Tipo de documento: Trabalho de conclusão de curso
• Idioma: por
• Título da fonte: Repositório Institucional da UFRN
• Texto Completo: https://repositorio.ufrn.br/handle/123456789/40617
• topic: Armadura mínima de flexão. Concreto Armado. Vigas. Ductilidade. Momento de fissuração.; Minimum flexural reinforcement. Reinforced Concrete. Beams. Ductility. Cracking Moment.; CNPQ::ENGENHARIAS

This paper shows the derivation of ratios and equations which give the minimum flexural (longitudinal) reinforcement area according to ABNT NBR 6118:2014, ABNT NBR 6118:2003, ACI 318-14 and Eurocode 2 (2004), as well as compares the results from each code. The derivation and results obtained for ABNT NBR 6118:2003 show that many considerations made to derive the minimum reinforcement ratios presented in the table 17.3 of this code are not in line with the theory exposed in the same code. ACI 318-14 presents the highest minimum reinforcement ratio; compared to ABNT NBR 6118:2014 it gives values at least 70% higher. ABNT NBR 6118:2014, in turn, gives minimum reinforcement ratios that are not more than 22% higher than the values calculated according to Eurocode2. Furthermore, it is presented the concept of size effect and its influence on determining minimum flexural reinforcement, as shown in Bruckner and Eligehausen (1998) and Ozbolt and Bruckner (1999). None of the codes studied take this effect into consideration.