1. Home
  2. TRID
  3. View Record
https://www.ntro.org.au/

ESTUDIO DE LA CORROSION EN BARRAS DE ACERO INOXIDABLE EN CONCRETO CONTAMINADO POR CLORUROS CUANDO SE LE APLICAN ESFUERZOS RESIDUALES

En la Peninsula de Yucatan (Mexico), se ha reportado la existencia del muelle (Progreso) construido en 1937-1941, utilizando acero inoxidable tipo 304 como material de refuerzo, que hasta la fecha se encuentra en buenas condiciones en comparacion con otro muelle construido (1960 en el mismo lugar) usando acero bajo contenido de carbono, el cual se encuentra completamente destruido. En inspecciones realizadas a dicha estructura durante (2003-2004), se observo la existencia de barras de acero inoxidable "304", mostrando estas signos de corrosion principalmente en los ganchos. Es comun que el acero inoxidable tenga problemas de corrosion bajo esfuerzo tomando en cuenta la presencia de cloruros. Al constituirse los ganchos a 90º o 180º, en los extremos de las barras para mejorar la adherencia de estas en el concreto, se generan esfuerzos de tension/compresion en el acero. Ademas durante las inspecciones realizadas al muelle se han determinado concentraciones de cloruros de hasta el 2% por peso del concreto, a la profundidad de la barra de refuerzo (10 cm.), lo que hace suponer que el acero inoxidable en esta construccion es susceptible a la corrosion. Por consiguiente en este trabajo se estudia el comportamiento de acero inoxidable 304 y 316 en concreto contaminado por cloruros y generando esfuerzos residuales en tension a las barras mediante ganchos de 90º y 180º, y se compara con resultados de barras rectas sin esfuerzo aplicado alguno. Se describen las pruebas realizadas en este proyecto, las cuales incluyen: la determinacion de las propiedades fisicas y quimicas de los materiales utilizados (concreto-acero inoxidable) y mediciones electroquimicas realizadas a la varilla de refuerzo de acero inoxidable con o sin esfuerzo residual. Se incluyen figuras, tablas, conclusiones y recomendaciones. Abstract: It has been reported the existence of a concrete pier built between 1937 and 1941, locatated in the Yucatan Peninsula (Mexico), which stainless steel was used as the reinforcement material. The pier is so far in good conditions after 65 years of being placed in service. In comparison another pier built in the 1960's in same location, where carbon steel was used as reinforcement, is totally damaged by corrosion and even is already demolished. During inspections performed to the pier during 2003 and 2004, the stainless steel showed some signs of corrosion at the end where mechanical deformation were made to the bars, also known as hooks. It is common that stainless steel could have corrosion problems under tensile stresses in environments where chlorides are present. When the stainless steel bar ends were deformed to form those hooks (90º or 180º), an improvement of the bar adherence with concrete is achieved, but tension/compression stresses are generated in the bar surface. In same inspections, concentrations of chlorides were determined and values between 1% and 2% by weight of the concrete, at the depth of the reinforcement bar (10 cm.), were obtained. Therefore, the stainless steel bars would be susceptible to stress corrosion cracking due to the residual stresses formed on those hooks. Consequently the aim of this work was to determine the performance of stainless steel 304 and 316 in concrete contaminated by chlorides, where residual stresses were applied by deforming smooth bars into 90º and 180º hooks. The electrochemical results were compared to the performance of straight bars with no residual stresses applied. The tests included the determination of the physical and chemical properties of the materials used (stainless and concrete) and electrochemical measurements of the stainless steel bars with and without residual stresses. Included figures, tables, recommendations.

Language

  • Spanish

Media Info

  • Pagination: xi+86p.
  • Serial:
    • PUBLICACION TECNICA
    • Issue Number: 287
    • Publisher: Instituto Mexicano del Transporte
    • ISSN: 0188-7297

Subject/Index Terms

Filing Info

  • Accession Number: 01335457
  • Record Type: Publication
  • Source Agency: Instituto Mexicano del Transporte
  • Files: ITRD
  • Created Date: Apr 13 2011 7:20AM