Sources: CP staff; ASTM International, West Conshohocken, Pa.; National Ready Mixed Concrete Association, Alexandria, Va.
Responding to market demand for portland cement and fly ash alternatives or companion agents, ASTM C09.24 Subcommittee on Supplementary Cementitious Materials has published C1945-24e1, Standard Specification for Raw or Calcined Natural Pozzolan for Use in Concrete. The release of C1945 sets the stage for separating raw pozzolan and metakaolin products from Subcommittee C09.24’s C618-23e1, Standard Specification for Coal Ash and Raw or Calcined Natural Pozzolan for Use in Concrete. Present C1945 requirements for natural pozzolans will match those of C618 Class N, which will continue in the heritage standard for an interim period. Future changes for natural pozzolan requirements will be made in C1945 and the C618 Class N reference dropped. Orders for the standard can be placed here.
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