The NIST / ACI / ASTM Workshop on Modelling Service Life and Life-Cycle Cost of Steel-Reinforced Concrete was focused on possibilities for developing and standardizing such models, specifically for concrete exposed to chlorides. The report includes summaries of ten invited presentations concerning model development and reports from working groups that addressed: I) the general problem of how best to meet the workshop objectives, ii) chloride transport mechanisms and test methods, iii) chloride thresholds for corrosion initiation, iv) corrosion rate and time to rehabilitate or replace, and v) life-cycle cost and service life prediction models. Several models for chloride transport to the steel are well advanced, but modelling of chloride thresholds and of corrosion rates pose difficulties that have yet to be overcome. Economic models for the life-cycle costing are in place and ready to use with service life models as they are developed. It was agreed that standard models for service life prediction and life-cycle costing are necessary. It was recommended that a simple, but useful model could and should be developed and standardized in the short term, with a more scientific model being a longer term objective. Model development will need to be supported by new standard test methods and by databases containing appropriate and reliable data. Standardization of the models would be expected to be carried out in ACI committees and standardization of test methods in ASTM. NIST's Partnership for High-Performance Concrete Technology would contribute to the development of models, test methods, and data.
Citation: NIST Interagency/Internal Report (NISTIR) - 6327
NIST Pub Series: NIST Interagency/Internal Report (NISTIR)
Pub Type: NIST Pubs
chlorides, concrete, corrosion, corrosion threshold, economics, models, reinforcement, service life, transport processes