Title:
Alkali-Silica Reaction in Five Dams in Southwestern United States
Author(s):
David Stark and G. W. De Puy
Publication:
Symposium Paper
Volume:
100
Issue:
Appears on pages(s):
1759-1786
Keywords:
alkali-aggregate reactions; concrete cores; concrete dams; cracking (fracturing); humidity; moisture; petrography; silica; tests; siliceous aggregates; General
DOI:
10.14359/3831
Date:
4/1/1987
Abstract:
The Bureau of Reclamation and Construction Technology Laboratories are conducting a joint program to study the effects of alkali-silica reactivity in concrete dams and to determine the remaining potential for further reactivity in the structures. The first phase of the study covers Coolidge Dam, near Globe, Arizona; Friant Dam, near Fresno, California; Matilija Dam, near Ventura, California; Parker Dan, near Lake Havasu City, Arizona; and Steward Mountain Dam, near Phoenix, Arizona. The three requirements for expansive alkali-silica reactivity are sufficient alkali, availability of moisture, and the presence of potentially reactive silica. The procedures used in this investigation include field measurements of the relative humidity of the concrete to determine if sufficient moisture is available to sustain a continued reaction, expansion measurements of cores immersed in water and in an NaOH solution, petrographic examination of the cores to identify reactive aggregate particles, and osmotic cell tests of aggregate particles to determine potential reactivity