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Effect of Drying Shrinkage Cracks and Flexural Cracks on Concrete Bulk Permeability.


pdf icon Effect of Drying Shrinkage Cracks and Flexural Cracks on Concrete Bulk Permeability. (2316 K)
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.
Telephone: 1-800-553-6847 or 703-605-6000;
Fax: 703-605-6900.
Website: http://www.ntis.gov
Order number: PB2000-105256

Keywords:

concretes; drying; cracking (fracturing); nuclear disposal; permeability; reinforced concretes; restrained shrinkage

Abstract:

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.