Rationale

CMU for construction of catch basins and manholes manufactured to meet C139 are machine-made using dry-cast concrete in a similar manner to other dry-cast manufactured concrete products including C55 (Building Brick), C90 (Loadbearing CMU), C129 (Nonloadbearing CMU), C1372 (SRW Units), C1623 (Masonry Lintels), C1634 (Facing Brick and other Facing Units), C1877 (Adhered CMU) and C1884 (Ballast Units). Until recently, only C1372, Specification for Dry-Cast Segmental Retaining Wall Units, referred to ‘Dry Cast’ in the title of the specification. In December 2024, ‘Dry-Cast’ was added to the title of C90-24a, Specification for Dry-Cast Loadbearing Concrete Masonry Units. In addition to adding ‘dry-cast’ to the title, an updated definition of ‘dry-cast’ was added to C90 and C1372 and ‘dry-cast’ was added to the keywords. To maintain consistency, this ballot item is proposing to add ‘Dry-Cast’ to the title of C139 as well as add a definition of ‘dry-cast’ and include it in the keywords. Similar ballot items will be drafted for the other related standards listed above. While it may not be strictly necessary to add the definition of ‘dry-cast’ to each of these standards, the task group thinks it will improve understanding and clarity to the users of the standard and will maintain consistency amongst all the standards. Note that an additional change is being made to update the Keywords of C139 to reference ‘hydraulic cement’ to be consistent with the other standards.