Alkali-Silica Reaction—Possible Cause of Map Cracking in Gunite
Publication: Journal of Performance of Constructed Facilities
Volume 17, Issue 3
Abstract
In this case study, a number of gunite swimming pools exhibited extensive map or alligator cracking that caused rough and uneven surfaces. The nature of the cracking pointed to alkali-silica reaction (ASR) as the cause of the cracking. Four test methods, the uranyl acetate method, petrographic examination, chemical analysis by electron microprobe, and X-ray diffraction, were used to investigate the presence of ASR within the gunite. Results showed (1) some evidence of ASR gel within the gunite using uranyl acetate; (2) the potential existence of alkali silica gel throughout the cement and within the fractures of the sand grains based on petrographic examination; (3) elevated levels of total alkali, indicating a potential for ASR to occur based on chemical analysis; and (4) tiny inclusions of thermonatrite (commonly found in ASR gel) based on X-ray diffraction. Results from each of the four test methods suggest, albeit inconclusively, the existence of ASR in the gunite. Additionally, the results of all of the four test methods did not contradict each other. Accordingly, it can be stated with some certainty that the distress in the gunite was due to ASR.
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References
ASTM. (1983). “Standard practice for petrographic examination of hardened concrete.” C856, West Conshohocken, Pa.
Derucher, K. N., and Korfiatis, G. P. (1988). Materials for civil and highway engineers, Prentice-Hall, Englewood Cliffs, N.J.
Leming, M. L.(1996). “Alkali-silica reactivity: Mechanism and management.” Min. Eng., 48(12), 61–64.
Mather, K., and Mather, B. (1991). “Aggregates.” The heritage of engineering geology: The first hundred years, G. A. Kiersch, ed., Geological Society of America, Boulder, Colo., 323–332.
Mielenz, R. C. (1962). “Petrography applied to portland cement concrete.” Reviews in engineering geology: Volume I, T. Fluhr and R. F. Legget, eds., Geological Society of America, Boulder, Colo., 1–38.
SHRP C-315 handbook for the identification of alkali-silica reactivity in highway structures. (2000). 〈http://leadstates.tamu.edu/asr/library/C315/index.stm#toc〉 (May 2002).
Smith, R. L. (1988). “Is the available alkali test a good durability predictor for fly ash concrete incorporating reactive aggregate?” Proc., 1987 Fall Meeting, Materials Research Society, Boston, 317–324.
U.S. Army Corps of Engineers. (1994). “Standard practice for concrete for civil engineering work structures—Appendix D: Alkali-silica aggregate reactions.” EM 1110-2-2000, 〈http://www.usace.army.mil/inet/usace-docs/eng-manulas/em1110-2-2000/a-d.pdf〉(May 2002).
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Copyright © 2003 American Society of Civil Engineers.
History
Received: Jan 31, 2002
Accepted: Jul 18, 2002
Published online: Jul 15, 2003
Published in print: Aug 2003
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