A comment on a previous ballot questioned whether the current 5% tolerance on ingredients for blended cement ingredients was appropriate, particularly for materials in low quantities. An example was given of a Type IP cement made with a silica fume content of 4%. The 5% (by mass of finished cement) limit currently in C595 and M 240 means that the cement could contain between 0% and 9% silica fume and still be considered the same product, even though cements with 9% or 0% silica fume might be expected to have significantly different performance characteristics. This proposal includes revised limits for variation in ingredient quantity.
Keywordsblended hydraulic cement; fly ash cement; hydraulic cement; portland blast-furnace slag cement; portland-limestone cement; portland-pozzolan cement; pozzolanic cement; slag; granulated blast furnace slag;