Prediction and progress of cracking of cover concrete caused by chloride-induced corrosion of steel reinforcement

The State Road Authorities are responsible for over 8,000 concrete bridges and in excess of 16,000 major culverts, with a replacement value exceeding $10 billion, many of which are located in aggressive environments. Chloride-induced corrosion of reinforcement is a major cause of damage to these structures. Budgeting for the repair requires prediction of the deterioration and time for intervention. Existing predictive models mainly rely on Fick's diffusion equations and are conservative approaches based on the premise that the service life of a reinforced concrete structure is over when chloride ions reach the reinforcement (t1). There is little information available on the behaviour of reinforced concrete elements after chloride ions reach the reinforcement, i.e., rust growth and initial cracking of concrete (stage t2), and during the propagation stage of corrosion, involving critical section loss of steel (stage t3). In this work, the time to first cracking of concrete and subsequent crack growth were predicted based on the corrosion rate of the reinforcement, which was a function of chloride content, and other parameters such as bar diameter and depth, concrete quality and the geometry of the element. This enabled a more realistic prediction of service life, inclusive of stages t2 and t3. (a) For the covering entry of this conference, please see ITRD abstract no. E214936.

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  • English

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  • Accession Number: 01050999
  • Record Type: Publication
  • Source Agency: ARRB
  • Files: ITRD, ATRI
  • Created Date: Jun 11 2007 1:06PM