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Descripción
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| Corrosion of the steel reinforcements is one of the main causes of deterioration of reinforced concrete structures and of decrease on their foreseen service life. The formation of rust on the corrugated steel surface causes cracking and detachment of the concrete and subsequent acceleration of the corrosion steel. Moreover, among the consequences of the corrosion reinforcements, there also are the loss of reinforcement carrying ability and the loss of ductility of the bars, which can affect the mechanical performance of the whole structure. With the aim of obtaining new information about how the corrosion modifies the mechanical properties of reinforcements, 12-mm diameter, 50-cm length corrugated bars have been corroded up to different levels. Then, the morphology of the attack caused on the reinforcements has been characterized and the bars have been tensile tested. For this study, 6 concrete slabs (compression strength 25 MPa at 28 days) with 500 x 260 x 100 mm size have been manufactured with 2% chloride added. 10 black steel bars have been embedded in each concrete slab. 30 cm of each bar were exposed to the corrosion inside the concrete, that¿s to say, only 60% of the length of bar was exposed to the attack, which is a relevant point for their mechanical performance. The corrosive attack has been accelerated by applying a constant anodic current of between the reinforcements and lead sheets placed on the surface of the slabs. Each slab was summited to accelerated corrosion for different times. After the accelerate corrosion process, the corrosion level of each bar was determined gravimetrically, ranging from 5% to 15%, regarding the weight of the length of the bar exposed to corrosion. The main pits were identified on each bar and their morphology were characterized using an optoelectronic microscopy. The progress of the attack has been related to microstructure of the bars and the presence of their outer martensite layer. Tensile tests of corroded and no-corroded bars were carried out following the UNE-EN 10002-1 standard. For the lowest corrosion levels tested, there are no clear relation among the visible pits and failure location of the bar. However, for higher corrosion levels, the failure always takes place from a pit that stands out for the mass loss of steel that implies and because of their mouth size, being often the maximum depth of the pit a somewhat less critical parameter. | |
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Internacional
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Si |
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Nombre congreso
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EUROCORR2018 |
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Tipo de participación
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960 |
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Lugar del congreso
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Krakow, Poland |
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Revisores
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Si |
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ISBN o ISSN
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0000-0000 |
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DOI
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Fecha inicio congreso
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09/09/2018 |
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Fecha fin congreso
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13/09/2018 |
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Desde la página
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140 |
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Hasta la página
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140 |
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Título de las actas
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Proceedings EUROCORR 2018 |