Several changes to the constituent materials section of ASTM C1670 are proposed: Remove Hydrated Lime this material is not used production of adhered manufactured stone masonry veneer units, and as such it is not necessary to include it in the list of acceptable materials. Aggregate grading requirements it is proposed here to add a clause that the gradation requirements of the specifications for aggregates (C33, C331) do not necessarily apply. There are situations in production of these units where special gradations are necessary to meet both unit requirements and facilitate production. This clause is already included in other similar masonry unit specifications (ASTM C90, C1634 for example). Remove ASTM C330 Currently, the standard allows for use of either ASTM C330 or C331 lightweight aggregates. C330 is for lightweight aggregates for structural concrete, while C331 is for lightweight aggregates for concrete masonry units. Referencing both standards is not necessary since a material that meets C330 will also comply with C331. C331 allows for additional materials (those that are the end product of coal or coke combustion) that are not allowed in C330. In order to simplify these requirements, it is proposed here to remove the reference to C330.
Keywordsadhered; cementitious; concrete; manufactured; manufactured stone; masonry; veneer;