237.36
City of Loveland Colorado
Material Specification
237 – UNDERGROUND DEVICES
PRECAST CONCRETE ELECTRICAL VAULTS
1
Scope
This specification states the minimum requirements for steel reinforced, precast concrete
underground electrical distribution vaults.
2
General
2.1
Specification Compliance
The manufacturer is responsible for understanding and complying with this
specification. The manufacturer shall not cause to be delivered any transformer that
does not meet or exceed these requirements.
2.2
Applicable Documents
The latest revisions of the documents, standards, codes, and requirements in effect
at the time of the invitation to bid apply unless more restrictive requirements are
imposed by this specification.
ASTM, all applicable requirements
2.2
Manufacturer Certification
Manufacturers shall be certified by NPCA or provide documentation showing
equivalency.
3
Design
The precast vault shall be designed to resist all dead loads and live loads for an H20-44
wheel load in accordance with the latest edition of AASHTO standard specifications for
highway bridges with an impact factor of 30 percent. The combinations of loads that
produce the maximum shear and moment shall be used to design the structure. The vault
shall have adequate reinforcing to resist the stresses resulting from the loading conditions.
All lids that contain block-outs shall be pedestrian rated for the block-out side only. All
other sections of lids shall be at least H-10 rated.
4
Construction
The strength at twenty- eight days shall be at least 4500 psi. The maximum nominal
aggregate size shall be ¾”. The vault shall be constructed to the dimensions indicated on
the attached drawings for the specific vault ordered. All appurtenances shall be firmly
fixed in the forms at all prescribed locations to prevent dislodgement during construction
and future use.
Date: 03-19-10
Revision: Strength ratings for vault lids added.
Specification 237.36
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237.36
City of Loveland Colorado
Material Specification
237 – UNDERGROUND DEVICES
4.1
4.2
5
Surfaces
The finished surface of all lids shall be flat and free of aggregate pockets and
honeycomb. Where minor defects occur, they shall be painted with cement grout,
patched with a one-to-one cement/sand mixture, and finished to match adjacent
surfaces while the concrete is still green.
Lifting Provisions
Lifting anchors (recessed lugs) shall be installed in the vault lid face. Threaded
inserts shall be provided in the bottom wall section of the vault.
4.3
Knockouts
Knockouts shall be reinforced with 6 x 6 /10x10 WWM extending a minimum of 8”
beyond the knockout in all directions.
4.4
Duct Terminators
Duct terminators shall be provided when specified in the drawing. The size will be
specified on the purchase order.
Material
5.1
Cement
The cement shall be Type I/II modified conforming to ASTM C150.
5.2
Fine Aggregate
Clean, natural sand shall be used in accordance with ASTM C33. Artificial or
manufactured sand is not acceptable.
5.3
Coarse Aggregate
Crushed stone, washed gravel, or other comparable inert granular material
conforming to ASTM C33 shall be used, except that clay and shale particles shall
not exceed one percent.
5.4
Water
Water shall be free of alkalies, acids, oil, organic matter, or any other substance that
would be harmful to the quality of the concrete.
Date: 03-19-10
Revision:
Specification 237.36
Page 2 of 3
52
237.36
City of Loveland Colorado
Material Specification
237 – UNDERGROUND DEVICES
5.5
Reinforcing Steel
All reinforcing material shall be structural grade conforming to either ASTM A615,
grade 60, including supplement S, or 706. 615 Rebar shall be wire-tied and not
welded. Rebar shall be the deformed bar type.
5.6
Frame and Cover
All reinforcing material shall be structural grade conforming to either ASTM A615,
grade 60, including supplement S, or 706. 615 Rebar shall be wire-tied and not
welded. Rebar shall be the deformed bar type.
6
Inspection
Loveland Water and Power reserves the right to inspect all products at the manufacturer’s
facility, at Loveland’s storage facility or at the job site. The inspection or the failure to
inspect does not relieve the supplier of the responsibility to conform to these specifications.
7
Warranty
The manufacturer guarantees that the vaults furnished under this specification are free of
defects. The manufacturer shall replace or repair defective items when they are discovered,
whether they be at the manufacturer’s facility, the City’s storage facility or at installation
site.
Date: 03-19-10
Revision:
Specification 237.36
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