Abstract
Abstract Supplementary cementitious materials (SCMs) generally have more variability in their alkali contents than portland cement. The alkali content of SCMs and cements is important as these can contribute to the initiation and progression of alkali-silica reaction (ASR). The “available alkali” test in ASTM C311, Standard Test Method for Sampling and Testing Fly Ash or Natural Pozzolans for Use in Portland-Cement Concrete, measures the amount of sodium and potassium in an SCM that are available to the pore solution in concrete and thus available to participate in the ASR. The relevance of the available alkali test has been questioned, particularly the length of the test and the unrepresentative initial pH of the reagent solution. This study evaluated modifications to the ASTM C311 available alkali test method that included varying the length of curing, increasing the pH of the reagent solution, and reducing the mass ratio of the SCM to calcium hydroxide to better represent conditions in real concrete. The modifications examined in this study produced results that were only marginally different from the ASTM C311 standard test method for determining available alkalis, suggesting that the existing test method may be appropriate for use in spite of its perceived drawbacks, and added complexity in testing is not necessary to improve relevance.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
