Title:
Sulfate Attack of Concrete: Reliability Analysis
Author(s):
David J. Corr, Paulo J. M. Monteiro, Kimberly E. Kurtis, and Armen Der Kiureghian
Publication:
Materials Journal
Volume:
98
Issue:
2
Appears on pages(s):
99-104
Keywords:
analysis; cement; sulfate; water-cement ratio
DOI:
10.14359/10193
Date:
3/1/2001
Abstract:
To determine the expected long-term performance of concrete in a sulfate-rich environment, a reliability analysis is performed using a previously developed model and data collected over more than 40 years by the U.S. Bureau of Reclamation (USBR). The reliability analysis contains three main phases: 1) an expected time to failure analysis; 2) a probability of failure analysis; and 3) a sensitivity analysis. This analysis demonstrates that the concrete mixtures of the USBR program subjected to a severe sulfate environment have expected times to failure of 19 to 89 years, depending on the concrete mixture proportions and the portland cement composition. Probability of failure increases with increasing exposure time, water-cement ratio (w/c), and C3A content, although at different rates. Through the use of a probability sensitivity analysis, it is found that uncertainty in the w/c is the most influential parameter in the reliability model; it is roughly twice as important as exposure time. Also, the influence of w/c is roughly one order of magnitude larger than the influence of the C3A content for cements with a C3A content less than 8%.