This specification covers the manufacture and purchase requirements of products intended for the assembly and construction of circular vertical precast reinforced concrete manholes and structures used in sewer and water works. Reinforced concrete shall consist of cementitious materials, mineral aggregates, and water, in which steel reinforcement has been embedded in such a manner so that the steel reinforcement and concrete act together. The allowable combination of cementitious materials shall be one of the following: Portland cement; Portland blast-furnace slag cement; slag modified Portland cement; Portland pozzolan cement; combination of Portland cement and ground granulated blast-furnace slag which shall conform to the requirements of Grade 100 or 120; combination of Portland cement and fly ash which shall conform to the requirements of Class F or C; or combination of Portland cement, ground granulated blast-furnace slag, and fly ash. Steel reinforcement shall consist of wire, wire fabric, or bars while the secondary synthetic fiber shall be a collated fibrillated polypropylene virgin fiber. Concrete products shall be subjected to steam, water, or sealing membrane curing and shall undergo compression and absorption tests to attain and determine the required compressive strength. The acceptance criteria and design of grade rings, flat slab tops, risers and conical tops, base sections, and steps and ladders shall also be determined.

1.1 This specification covers the manufacture and purchase requirements of products used for the assembly and construction of circular vertical precast reinforced concrete manholes and structures used in sewer, drainage, and water works.

1.2 Part I, Sections 1-11, of this specification presents general requirements and requirements that are common to each precast concrete product covered by this specification.

1.3 Part II of this specification presents specific requirements for each manhole product in the following sections:

Note 1—Future products will to be included in Part II in a future revision of this specification.

1.4 This specification is the inch-pound companion to Specification C 478M; therefore, no SI equivalents are presented in the specification.

Note 2—This specification is a manufacturing and purchase specification only and does not include requirements for backfill, or the relationship between field load conditions and the strength requirements of the manhole products and appurtenances. Experience has shown, however, that the successful performance of this product depends upon the proper selection of the product strength, type of foundation and backfill, and care in the field installation of the manhole products and connecting pipes. The owner of the project for which these products are specified herein is cautioned to require inspection at the construction site.