Rapid hardening hydraulic cements are used in a variety of applications in which reduced cementitious contents are desired or early service is needed. Included among these applications are paving, construction, stucco, mortar and block. A newly approved ASTM International standard covering these cements, ASTM C1600/C1600M, Specification for Rapid Hardening Hydraulic Cement, has been developed by Subcommittee C01.13 on Special Cements, part of ASTM International Committee C01 on Cement.
According to James K. Hicks, CERATECH Inc., and chair of C01.13, four types of cement are covered by ASTM C1600/C1600M:
Type URH—ultra rapid hardening, for use where ultra high early strength is desired;
Type VRH—very rapid hardening, for use where very high early strength is desired;
Type MRH—medium rapid hardening, for use where mid-range rapid hardening, high early strength is desired; and
Type GRH —general rapid hardening, for use when the higher strength properties of Type VRH or a Type MRH cement is not required.
“ASTM C1600 lists minimum requirements for compressive strength, setting time, shrinkage and soundness (autoclave expansion),” says Hicks. “Optional specifications for sulfate expansion, alkali silicate reactions with aggregates, heat of hydration and expansion in water are also listed.”
Hicks goes on to note that ASTM C1600 cements that require calcined clinker typically use much less heat and evolve less carbon dioxide than other forms of clinker production.
“Some C1600 cements are made principally from coal combustion products, thereby requiring no additional fuel use evolving no additional carbon dioxide,” says Hicks.
For technical information, contact James K. Hicks, CERATECH Inc., Baltimore, Md. (phone: 936-697-2893; jim.hicks@ceratechinc.com). Committee C01 will meet Dec. 9-11 during December committee week in Atlanta, Ga.
ASTM International welcomes and encourages participation in the development of its standards. ASTM’s open consensus process, using advance Internet-based standards development tools, ensures worldwide access for all interested individuals. For more information on becoming an ASTM member, please contact Scott Orthey, ASTM International (phone: 610-832-9730; sorthey@astm.org).
Release #8356/September2009
