Performance Limits for Evaluating Supplementary Cementing Materials Using Accelerated Mortar Bar Test

Originally developed for alkali-silica reactive aggregate identification, the accelerated mortar bar test (AMBT) has been widely used for supplementary cementing materials (SCM) preventive action evaluation. Recently, for example, a modified AMBT version was developed and published as an ASTM standard test method for testing pozzolan and slag effectiveness for alkali-silica reaction expansion control. The authors compare AMBT reactive aggregate-SCM combination test results with performance of the same material combinations in field-exposed concrete blocks, concrete structures, and concrete prisms undergoing laboratory expansion tests. Results show that concrete performance in both laboratory and field conditions agrees with the AMBT 14-day 0.10% expansion limit. When used in concrete, there was a very low risk of damage resulting when SCM and reactive aggregate combinations that passed this limit were tested in mortar. Using the 14-day expansion limit, the required SCM minimum can be determined for expansion control in a given reactive aggregate, and the result agrees well with the SCM amount required for concrete cracking prevention. Test duration extension (e.g. 28 days) is overly conservation and results in much higher SCM level estimates (on average, 1.5 times) for expansion control than what concrete actually requires.

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  • Authors:
    • Thomas, Michael D A
    • Fournier, Benoit
    • Folliard, Kevin J
    • Shehata, Medhat H
    • Ideker, Jason H
    • Rogers, Chris
  • Publication Date: 2007

Language

  • English

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Filing Info

  • Accession Number: 01049939
  • Record Type: Publication
  • Files: TRIS
  • Created Date: May 2 2007 10:10AM