Replacement of the Final Time of Setting Maximum with an Initial Time of Setting Maximum as measured with the Gillmore Needles in ASTM C 91, C 1328, and C 1329

摘要

ASTM Subcommittee C01.11 on Masonry Cement, established a task group on methods of test which determined whether the final time of setting maximum limit could be replaced with an initial time of setting maximum limit. A review was conducted of 52 Cement and Concrete Reference Laboratory proficiency samples (spanning 26 years) and data from the Portland Cement Association Masonry Cement Survey. Findings indicate a very reliable and simple linear relationship exists between masonry cement initial and final Gillmore time of setting. Data is presented which resulted in a specification change to ASTM C 91, ASTM C 1328, and ASTM C 1329 in 2005.