Item No. 505
This item shall govern the furnishing of materials and the methods of constructing a Portland cement concrete encasement or encasement pipe.
505.2 Submittals
The submittal requirements of this specification item include:
A. Type, of pipe, construction methods and sequence,
B. Aggregate types, gradations and physical characteristics for the Portland cement concrete mix,
C. Proposed proportioning of materials for the mortar mix.
A. Portland Cement Concrete
The Portland cement concrete shall conform to Class D Concrete, Item No. 403, "Concrete for Structures".
B. Pipe
Portland Cement concrete pipe shall conform to ASTM C-76, Class III or better.
Corrugated Metal Pipe (CMP) shall conform to Section 510. 2 (8)(o) of the Standard Specification Item No. 510, "Pipe".
Steel Pipe shall conform to ASTM A134 with a minimum thickness of 3/8 inch for pipe with a diameter of 16 inches and greater.
C. Grout
Grout shall consist of not less than 6 sacks Portland cement per cubic yard and clean washed sand mixed with water. The grout shall have a consistency such that the grout will flow into and completely fill all voids. If allowed by the Engineer or designated representative, an air entraining admixture may be added to facilitate placement.
When indicated on the Drawings or acceptable to Engineer or designated representative, concrete encasement shall be placed to protect the pipe. Pipe or bedding shall not be placed where:
(a) the top of the pipe would have less than 30 inches of cover,
(b) the ground water invades the trench, or
(c) the trench bottom is of unstable material.
If either of these conditions is encountered, the Engineer or designated representative shall be notified and may direct the Contractor to:
(a) encase the pipe with concrete,
(b) change pipe material, or
(c) use a higher strength class of pipe.
Concrete encasement shall extend from 6 inches below to 6 inches above the outer projections of the pipe over the entire width of the trench in accordance with Standard Detail 310,” Concrete Encasement”.
505. 5 Measurement and Payment
Concrete encasement will be measured by the lineal foot, for size of pipe being encased, complete in place. The measurement will be made between ends of the encasement, along the central axis as installed.
Encasement pipe will be measured by size of encasement installed, complete in place. The measurement will be made between the ends of the pipe, along the central axis as installed.
505.6 Payment
Work performed and materials furnished as prescribed by this item will be subsidiary to Item No. 510, "Pipe" unless included as a separate pay item in the contract. When included for payment, it shall be measured as provided under "Measurement" and will be paid at the unit bid price per lineal foot for "Concrete Encasement" of the size indicated on the Drawings. The unit bid price shall include full compensation for furnishing all materials, pipe for all preparation, hauling, installation and for all labor, tools, equipment and incidentals necessary to complete the work, including bench excavation and disposal of surplus material.
Payment, when included as a contract Pay Item, will be made under one of the following:
Pay Item: Concrete Encasement for ___ Dia. Pipe - Per Lineal Foot.