In this study, low carbon steel fibres were corroded to various corrosion degrees by cycling in 3.5% NaCl solution and 60 °C oven, and by applying a designed current density of 20 mA/cm2. Then the corrosion characters and corrosion degree on tensile strength of the two types of corroded steel fibres were investigated. It was found that the cycles induce pitting and the current induces relatively uniform corrosion. The results of tensile test show that the actual tensile strength of steel fibres was reduced in the case of pitting, while it was marginally affected by uniform corrosion. As the corrosion degree increased, both of the nominal tensile strength and elongation of the two types of corroded steel fibres decreased. In addition to weight loss, local section loss at the pits is the main reason for further degradation of the mechanical properties of steel fibres and gives a brittle failure. Pitting corrosion leads to higher decrease in tensile strength compared to uniform corrosion.Pitting induces a significant reduction in elongation giving a brittle failure.
AbstractIn this study, low carbon steel fibres were corroded to various corrosion degrees by cycling in 3.5% NaCl solution and 60℃ oven, and by applying a designed current density of 20 mA/cm 2 . Then the corrosion characters and corrosion degree on tensile strength of the two types of corroded steel fibres were investigated. It was found that the cycles induce pitting and the current induces relatively uniform corrosion. The results of tensile test show that the actual tensile strength of steel fibres was reduced in the case of pitting, while it was marginally affected by uniform corrosion. As the corrosion degree increased, both of the nominal tensile strength and elongation of the two types of corroded steel fibres decreased. In addition to weight loss, local section loss at the pits is Corresponding author. Tel.: +61 2 4221 4762; fax: +61 2 4221 3238.E-mail address: mhadi@uow.edu.au (M.N.S Hadi).2 the main reason for further degradation of the mechanical properties of steel fibres and gives a brittle failure.
Summary
In this study, the flexural tests were conducted to investigate the effects of temperature, steel fiber, nano‐SiO2, and nano‐CaCO3 on flexural behavior of concrete at high temperatures. The load‐deflection curves of fiber and nanoparticle reinforced concrete (FNRC) were measured both at room and high temperatures. Test results show that the load‐deflection curves become flatter, and the flexural strength, peak deflection, and energy absorption capacity decrease seriously with the increase of temperature. Both steel fiber and nanoparticles could significantly improve the flexural behavior of the concrete at room and high temperatures. The energy absorption capacity of FNRC before the peak point increases with the increase of steel fiber volume fraction. The improvement of nano‐SiO2 on flexural strength of FNRC at high temperature is better than that at room temperature, but the enhancement on energy absorption capacity is reverse. Nano‐SiO2 is more effective than nano‐CaCO3 in improving flexural behavior of concrete both at room and high temperatures.
Glass fiber reinforced polymer (GFRP) pultruded rectangular tubes were used externally to confine Reinforced Concrete (RC) beams in this experimental study, aiming to improve the corrosion resistance of the RC beams in the harsh environment (e.g., Hydraulic structures and Marine structures). The flexural behavior of the composite beams reinforced with GFRP tubes was investigated by using four-point bending test. The experimental program involved the testing of six beam specimens reinforced with or without the GFRP tubes, and the main parameters investigated included the reinforcement ratio of the tensile steel bars and the stirrup spacing. The experimental results show that the flexural strength and stiffness of the RC beam members were significantly improved by using the GFRP tubes. The brittle failure of the beam specimens was caused by the local failure at one loading pints on the top flange of the GFRP tubes. The higher reinforcement ratio of the tensile steel bars contributed to the improvement of the flexural strength and bending stiffness. The stirrup spacing had little effect on the flexural behavior of the beam specimens in the proposed composite beams.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.