Document Archives

Service Life Prediction of LWA Concrete in Chloride Environment

• ID:

  939

• ESCSI:

  4350.008

• Author:

  Maage, Magne; Steinar Helland and Jan Eric Carlsen - Editors: I. Holand, T.A. Hammer, F. Fluge

• Publication Name:

  International Symposium on Structural Lightweight Aggregate Concrete, 1995 Proceedings

• Type of Publication:

  Paper

• Publisher:

  Norwegian Concrete Association

• Dated:

  1995

• Issue/Volume:

  June 20-24

• Other ID:

• Page(s):

  563-574

• Reference List:

  Y

• Abstract:

  Most of the structural lightweight aggregate (LWA) concrete in Norway is used in marine environment where chloride ingress may cause reinforcement corrosion. A model for chloride ingress into LWA concrete and prediction of service life is developed as a part of the research program “Lightcon”. The model is based on Fick’s second law of diffusion with the modification that the diffusion coefficient is time dependent. Service life is devined as the initiation period.The model is presented shortly including the most important equations for estimating service life. Results both from laboratory tests and field exposure of actual LWA concretes are used as input into the model and service life is estimated. All the tested LWA concretes have a relatively low w/c-ratio where capillary absorption is almost non existent.
  The calculations show that the new generation of LWA concrete with an effective w/c-ratio less than 0.40 has a service life exceeding 100 years, supposing that the concrete cover is as specified.