Effect of Drying Shrinkage Cracks and Flexural Cracks on Concrete Bulk Permeability.
Effect of Drying Shrinkage Cracks and Flexural Cracks on
Concrete Bulk Permeability.
Snyder, K. A.
NISTIR 6519; 26 p. May 2000.
Sponsor:Nuclear Regulatory Commission, Washington, DC
Available from: National Technical Information Service
(NTIS), Technology Administration, U.S. Department of
Commerce, Springfield, VA 22161.
1-800-553-6847 or 703-605-6000;
Order number: PB2000-105256
concretes; drying; cracking (fracturing); nuclear
disposal; permeability; reinforced concretes; restrained
A review of the computer program 4sight has revealed
that an accurate prediction of water transport through
the concrete depends upon an accurate prediction of the
crack formation within the concrete. A model for
predicting both the width and the spacing of flexural
and drying shrinkage cracks is employed. The results are
used to estimate the composite concrete permeability. A
deterministic structural analysis is performed to
demonstrate the procedure. The analysis is repeated
using a Monte Carlo approach in order to assess the
effects of input parameter variability. The principles
outlined in this report will be incorporated into the
4sight computer program. The prediction of shrinkage and
flexural crack width and crack spacing will allow the
user to consider the effects of various concrete mixture
designs. The mean values reported will assist the user
in determining which factors have the greatest effect on
the expected crack width and crack spacing. The reported
uncertainties will help the user assess the maximum
statistical variation allowed for critical concrete
mixture and structural design parameters.