Alkali-Silica Reaction - Possible Cause of Map Cracking in Gunite

Authors

Moses Karakouzian, University of Nevada, Las VegasFollow
Mehmet N. Okuyan, Terracon Consulting Engineers & ScientistsFollow
Nick Hudyma, University of Nevada, Las VegasFollow

Document Type

Article

Publication Date

8-2003

Publication Title

Journal of Performance of Constructed Facilities

Volume

17

Issue

3

First page number:

118

Last page number:

125

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.

Keywords

Cement; Cements (building materials); Chemical reactions; Civil engineering; Construction industry; Cracks; Gunite; Gunite—Testing; Materials—Testing; Materials testing; Shotcrete; Shotcrete--Testing

Disciplines

Civil and Environmental Engineering | Construction Engineering and Management | Engineering | Environmental Sciences | Materials Science and Engineering

Language

English

Permissions

Use Find in Your Library, contact the author, or interlibrary loan to garner a copy of the item. Publisher policy does not allow archiving the final published version. If a post-print (author's peer-reviewed manuscript) is allowed and available, or publisher policy changes, the item will be deposited.

Repository Citation

Karakouzian, M., Okuyan, M. N., Hudyma, N. (2003). Alkali-Silica Reaction - Possible Cause of Map Cracking in Gunite. Journal of Performance of Constructed Facilities, 17(3), 118-125.
http://dx.doi.org/10.1061/(ASCE)0887-3828(2003)17:3(118)