Title:
Alkali-Silica Reaction Mitigation: State of the Art
and Recommendations
Author(s):
L. J. Malvar, G. D. Cline, D. F. Burke, R. Rollings, T. W. Sherman, and J. L. Greene
Publication:
Materials Journal
Volume:
99
Issue:
5
Appears on pages(s):
480-489
Keywords:
alkali-silica reaction; concrete; fly ash; silica fume; slag.
DOI:
10.14359/12327
Date:
9/1/2002
Abstract:
Alkali-silica reaction (ASR) mitigation techniques from various states in the United States, and from various countries and international organizations, were assessed and summarized. A set of recommended mitigation procedures was developed that requires not only the use of low-alkali cement, but replacement of part of it by Class F fly ash (or Class N pozzolan) (25 to 40% by weight), or ground granulated blast-furnace slag (GGBFS), Grade 100 or 120 (40 to 50% by weight), or a combination of both. The Class F fly ash (or Class N pozzolan) should also have a maximum of 1.5% available alkali, a maximum 6% loss on ignition, and a maximum of 8% CaO (lime). A modified ASTM C 1260 using the actual mixture is recommended for ASR testing. In addition to mitigating ASR, these recommendations are expected to: 1) reduce concrete costs; 2) enhance the durability of concrete; 3) increase fly ash and GGBFS recycling; and 4) support the 1997 Kyoto protocol by significantly reducing CO2 production. If 25% of all cement was to be replaced, total savings to the United States economy could be in excess of $1 billion every year.