Title:
Landmark Series: How Good is Good Enough?
Author(s):
Edward A. Abdun-Nur
Publication:
Concrete International
Volume:
25
Issue:
6
Appears on pages(s):
27-41
Keywords:
DOI:
Date:
6/1/2003
Abstract:
How good should concrete be to serve its intended purpose? To answer this, several typical specifications are evaluated statistically relating results from an average project to physical job conditions. Concludes that minimum strength specifications are unrealistic, not generally met in practice, and tend to obscure the real safety factor. However, specifications based on average strength geared to coefficient of variation, permitting a reasonable number of low strength values, are more realistic, lower costs, reduce maintenance, and permit the safety factor to be determined before construction starts. A probability of 10 to 20 percent of strengths being below design strength provides better concrete than obtained currently under minimum strength specifications.