Abstract:
Carbon-steel-bar corrosion of reinforced concrete is considered one of the biggest problems in civil construction durability in marine environments. Thus, many studies are developed aiming at understanding bar corrosion mechanisms and at finding corrosion mitigation methods for concrete structures installed in the mentioned environments. To achieve the success in these studies, the definition and preparation of test specimens for the accelerated corrosion tests, which should represent the installed conditions and the environment corrosivity of the studied reinforced concrete, are very important. This work aimed at the definition and the preparation of reinforced concrete specimens which will be used to help find alternatives for carbon steel bars and also to use for protectiontechnique-efficiency evaluations of concrete structures installed in tropical marine environments, typical of Brazilian coasts. The specimens were defined based on the ASTM A955: 2015 and ASTM G109: 2007. Preliminary tests were taken to assess some of the parameters proposed by these standards. These tests were important for adapting the recommended methodologies to the proposed goals. The preliminary tests also allowed for planning the logistic and predicting the necessary time for preparing the 300 specimens necessary for the intended studies. This large number was necessary because the study included the following alternative bars: coated carbon steel (zinc coated and zinc plus epoxy dual-coated) and AISI 304 and UNS 32604 (lean duplex) stainless steels. The coated steel bars were considered in the studies because they are widely used in reinforced structures installed in chloride-contaminated environments, as marine environments. The stainless steels were also considered since they are typically used when a very long useful life is required or when there are restrictions for the structure maintenance. Test specimens were included to evaluate the efficiency of cathodic protection of carbon steel bars. Finally, protection–system-free carbon steel bars were included as a reference.
Reference:
ARAUJO, Adriana; RIBEIRO, José Luis Serra; CARDOSO, Juliana Lopes; PACHECO, Mayara Stecanella; SILVA, Carlos Alberto da; RUFINO, Cesar Henrique; BRAGA, Marcos Vinícius da Silva; BRUNELLI, Renata Angelon; ROSA, Thales Gomes, PANOSSIAN, Zehbour. Definição e preparação de corpos de prova de concreto armado destinados a ensaios acelerados de corrosão de armaduras. Revista IPT, Tecnologia e Inovação, v.1, n.3, p. 41-62, dez., 2016.
Access to the article on the Journal website:
http://revista.ipt.br/index.php/revistaIPT/article/view/31/19
Carbon-steel-bar corrosion of reinforced concrete is considered one of the biggest problems in civil construction durability in marine environments. Thus, many studies are developed aiming at understanding bar corrosion mechanisms and at finding corrosion mitigation methods for concrete structures installed in the mentioned environments. To achieve the success in these studies, the definition and preparation of test specimens for the accelerated corrosion tests, which should represent the installed conditions and the environment corrosivity of the studied reinforced concrete, are very important. This work aimed at the definition and the preparation of reinforced concrete specimens which will be used to help find alternatives for carbon steel bars and also to use for protectiontechnique-efficiency evaluations of concrete structures installed in tropical marine environments, typical of Brazilian coasts. The specimens were defined based on the ASTM A955: 2015 and ASTM G109: 2007. Preliminary tests were taken to assess some of the parameters proposed by these standards. These tests were important for adapting the recommended methodologies to the proposed goals. The preliminary tests also allowed for planning the logistic and predicting the necessary time for preparing the 300 specimens necessary for the intended studies. This large number was necessary because the study included the following alternative bars: coated carbon steel (zinc coated and zinc plus epoxy dual-coated) and AISI 304 and UNS 32604 (lean duplex) stainless steels. The coated steel bars were considered in the studies because they are widely used in reinforced structures installed in chloride-contaminated environments, as marine environments. The stainless steels were also considered since they are typically used when a very long useful life is required or when there are restrictions for the structure maintenance. Test specimens were included to evaluate the efficiency of cathodic protection of carbon steel bars. Finally, protection–system-free carbon steel bars were included as a reference.
Reference:
ARAUJO, Adriana; RIBEIRO, José Luis Serra; CARDOSO, Juliana Lopes; PACHECO, Mayara Stecanella; SILVA, Carlos Alberto da; RUFINO, Cesar Henrique; BRAGA, Marcos Vinícius da Silva; BRUNELLI, Renata Angelon; ROSA, Thales Gomes, PANOSSIAN, Zehbour. Definição e preparação de corpos de prova de concreto armado destinados a ensaios acelerados de corrosão de armaduras. Revista IPT, Tecnologia e Inovação, v.1, n.3, p. 41-62, dez., 2016.
Access to the article on the Journal website:
http://revista.ipt.br/index.php/revistaIPT/article/view/31/19
