A new standard, ASTM C1738, Practice for High-Shear Mixing of Hydraulic Cement Pastes, provides for preparing a mixture of cement paste that will simulate the shearing experienced by the cement paste in concrete, and was developed by Subcommittee C01.22 on Workability, part of ASTM’s Committee C01 on Cement.
According to Chiara Ferraris, physicist, National Institute of Standards and Technology, and chairman of C01.22, the proper mixing of cement paste, as described in ASTM C1738, is essential for various proposed test methods currently under development by the subcommittee. Primary users of ASTM C1738 will be operators conducting measurement using fresh (before setting) cement paste. Ferraris also notes that C01.22 welcomes participation in its standards development work. Proposed standards currently being developed by C01.22 include ASTM WK17836, Guide for Rheological Properties of Hydraulic Cementitious Paste Using a Rotational Rheometer; and ASTM WK27311, Test Method for Measurement of Cement Paste Consistency Using a Mini-Slump Cone.
The next ASTM Committee C01 meeting is Dec 7–9, 2011 as part of December Committee Week in Tampa, Fla. More information on the event or ASTM can be found at www.astm.org.