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Primary Topic: Pavement Testing
Description: The vital role of air entrainment in preventing freeze-thaw damage in concrete is well known and well documented [Powers 1949]. Through the action of an air entraining agent (AEA) added to fresh concrete, an air void system comprised of various microscopic voids is established. There are several parameters of the air void system, which are considered important indicators of freeze-thaw resistance. Measuring these parameters and their adequacy provides extremely useful information on concrete freeze-thaw resistance.
This report documents the results of a round-robin study of the ASTM C 457 linear traverse method, which was initiated to access the typical variability associated with the linear traverse test when performed by a human operator. The round robin was performed as part of a national pooled-fund study, led by the Missouri Department of Transportation (MoDOT), and sponsored by 13 states, entitled "Advanced Research...of a Fully Automated Image analysis system." The goal of the pooled-fund study was to refine and complete the development of a fully automated, computer-based linear traverse system, which could provide results equal to or better than those of a linear traverse performed by a human operator. Thus, the round robin study was undertaken to access accuracy and precision of a human-based linear traverse for which the automated system could be measured against.
FHWA Publication Number:
Publication Year: 2005