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Alkali-Silica Reaction and High Performance Concrete.


pdf icon Alkali-Silica Reaction and High Performance Concrete. (1348 K)
Ferraris, C. F.

NISTIR 5742; 24 p. August 1995.

Available from:

National Technical Information Service
Order number: PB96-131587

Keywords:

building technology; alkali-silica reaction; high performance concrete; concretes; standard testing

Abstract:

Damage due to alkali-silica reaction (ASR) in concrete is a phenomenon that was first recognized in the U.S. since 1940 and has since been observed in many countries. Despite numerous studies published, the mechanism is not yet clearly understood. Nevertheless, the three major factors in concrete have been identified, i.e., the alkalies contained in the pore solution, reactive amorphous or poorly crystallized silica present in certain aggregates, and water. In this study, we attempted to address the question: is high-performance concrete (HPC) susceptible to ASR? Researchers have not reached an agreement on this matter because factors other than the three major ones (pore solution alkalinity, aggregate morphology and water presence) play a significant role in the occurrence of ASR; these factors include aggregate gradation, w/c and compressive strength. It was found that air content is the most important variable (other than the three majors factors cited above) that increase expansion of concretes affected by ASR. This study indicates that even HPC should be susceptible to ASR if reactive aggregates are used.