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Pore Structure and Carbonation of Lightweight Concrete after 10 Years Exposure

• ID:

  961

• ESCSI:

  4374.001

• Author:

  Swamy, R.N. and E.D. Tiang

• Publication Name:

  Special Publication - 136

• Type of Publication:

  Paper

• Publisher:

  American Concrete Institute

• Dated:

  1992

• Issue/Volume:

• Other ID:

• Page(s):

  377-395

• Reference List:

  Y

• Abstract:

  The problem of concrete deterioration and its durability has become a matter of great concern to everyone involved in the construction industry. Carbonation and chloride ingress are the two major sources of deterioration, and the penetration of both is influenced by the pore structure of the concrete. This paper presents data on the pore structure, carbonation depths and the interrelationship between the two of structural lightweight concrete after ten years’ outdoor exposure in the industrially polluted area. The concrete was made with expanded slate aggregate using either all lightweight aggregates or with part of the lightweight fines replaced by sand. Both cement content and water-cement ratios were varied. The results showed that the total pore volume was influenced by both the water-cement ratio and the fine aggregate content of the concrete. The total pore volume was higher for concretes containing all lightweight fines than for concrete with part replacement of fines by sand. However, for a given pore volume, carbonation was higher for the concrete containing sand than for concrete containing all lightweight aggregates. This phenomenon is explained in terms of the pore structure of the concrete, and a pore structure characteristics parameter is introduced to correlate carbonation with pore volume.