resumo
This paper concentrates on the changes on the corrosion rate of the steel bars of RC columns due to their wrapping with glass fiber-reinforced polymers (GFRPs). RC cylindrical laboratorial specimens, both unwrapped and wrapped with GFRP, were immersed in a sodium chloride solution for 20 months. The changes on concrete resistivity and the corrosion process were followed by open potential measurements and electrochemical impedance. It was possible to quantify the influence of the GFRP jackets in the solution uptake and on the corrosion of the steel reinforcement. The results showed a delay on the diffusion of the solution into concrete due to the presence of the GFRP, which allowed that the bars remained in a passive state for longer immersion periods. The GFRP barrier lowered the rate of uptake of the solution and the chloride ion penetration. However, the GFRP jacket may have the properties as a physical barrier reduced due to imperfect application. The incomplete concrete saturation makes oxygen available, thus promoting an intense corrosion activity at the rebars. (C) 2014 American Society of Civil Engineers.
palavras-chave
HIGH-PERFORMANCE CONCRETE; IMPEDANCE SPECTROSCOPY; WRAPPED CONCRETE; CEMENT PASTE; FLY-ASH; BEHAVIOR; COMPOSITE; CHLORIDE; TEMPERATURE; REBARS
categoria
Construction & Building Technology; Engineering; Materials Science
autores
da Fonseca, BS; Castela, AS; Silva, MAG; Duarte, RG; Ferreira, MGS; Montemor, MF
nossos autores
Mário Guerreiro Silva Ferreira
Professor(a) Jubilado(a)agradecimentos
The writers acknowledge Fundacao para a Ciencia e Tecnologia (FCT) for the financial support through project PTDC/ECM/100538/2008 and to Escola Superior de Tecnologia do Barreiro for the use of their laboratories and equipment.