Title:
Experimental Asymptotic Analysis of Expansion of Concrete Exposed to Sulfate Attack
Author(s):
Paulo J. M. Monteiro and Kimberly E. Kurtis
Publication:
Materials Journal
Volume:
105
Issue:
1
Appears on pages(s):
62-71
Keywords:
models; saturation curves; sulfate attack; water-cement ratio
DOI:
10.14359/19208
Date:
2/1/2008
Abstract:
This study reviews the limitations of existing mathematical models to predict damage to concrete exposed to sulfate attack; and then, based on long-term experimental results, proposes scaling laws for the expansion of concrete exposed to sodium sulfate solution. After an initiation time, the expansion of concrete samples with high and moderate (that is, greater than 0.5) water-cement ratios (w/c) follow a definite scaling law. Research results demonstrate that the scaling exponent depends on the cement composition but does not depend on the original w/c. The initiation time is a function of both the w/c and the cement composition. This dependency on the type of cement and the w/c can be expressed by a potential of damage (Pd) index, which gives a measure of the sensitivity to damage for a given concrete mixture proportion. Concrete samples, which were cast with a low w/c and sulfate-resistant cements and tested over a 40-year period, exhibited no intermediate asymptotic behavior; instead, saturation curves were observed.