15-5 1505 -5 Concrete Encasement of Utility Lines
Encase existing or proposed utility lines in concrete for protection in areas as shown on the utility plans or as directed by the Engineer . Place the concrete completely around the line with a minimum thickness of 6 inches . 1505 -6 MEASUREMENT AND PAYMENT Foundation Conditioning Material, Minor Structures and Foundation Conditioning Geotextiles will be measured and paid as provided in Article 300-9. Asphalt Plant Mix , Pavement Repair will be measured and paid as provided in Article 654-4. Class B Concrete for Encasing Utility Lines will be measured and paid in cub ic yards of concrete, measured in place. __" Concrete Sidewalk and __" Concrete Driveways will be measured and paid in accordance with Article 848 -4. Trenching, excavation, pipe laying, bedding, backfilling and disposal of unsuitable materials for utility construction are included in the contract price for the applicable utility item and no separate measurement or payment will be made. The following work and items are included in the contract price for the applicable utility item 16 and no separate measurement or payment will be made for items (A) through (F) below:
A.Undercut or Wet Excavation,
B.Dewatering of Excavation,
C.Shoring and Sheeting (except temporary shoring for maintenance of traffic covered elsewhere in the contract and protection of structures and buildings ),
D.Thrust Restraint,
E.Bedding Material, or
F.Select Material for Backfill. Payment will be made under: Pay Item Pay Unit Class B Concrete for Encasing Utility Lines Cubic Yard 1510 -1 DESCRIPTION Provide water lines suitable for use in transporting potable water. 1510 -2 MATERIALS Refer to Division 10. Item Section Water Pipe and Fittings 1036 The Contractor may use any of the water pipe specified under Section 1036 except where a particular type pipe is specified in the plans or required by environmental regulations or Departmental policy. The Contractor shall verify that the pipe is appropriate for the test pressure of the system and the external loading. Use ductile iron fitting s on water lines 4 inches or larger. Use #12 AWG solid- copper wire with blue insulation for the utility locator wires.
15-6 Use 2 inch plastic marking tape colored blue with “ Caution Water Line ” or similar wording,
permanently printed at 36 inch centers. Protec t steel rods and other metal clamps and lugs by galvanizing or painting with approved bituminous paint as found on the NCDOT APL . 1510 -3 CONSTRUCTION METHODS
A.General Meet the installation standards of AWWA or ASTM for water line construction. Apply Section 1505 for excavation, trenching, pipe laying and backfill to water line installation. Install small diameter pipe (4 inches or less) under existing pavement by a trenchle ss method at no additional cost to the Department . Connect the ends of the water service piping using AWWA C800 type couplings or fittings. Make NPT screw joints with a double wrap of a polytetrafluoroethylene (PTFE) tape and torque as required by the manufacturer. Store plastic pipe out of direct sunlight until burying. All plastic pipe showing discoloration or deterioration will be rejected for use and replaced with suitable pipe as specified under Article 106-9. Install water lines with 36 inches to 42 inches of cover to finished grade unless otherwise directed or approved by the Engineer . Install water lines with greater cover for short distances to accommodate utility controls, to make tie -ins to existing facilities, to eliminate high points in the p ipeline or to provide clearance between existing and proposed utilities, drainage, other obstacles or actual field conditions.
B.Testing and Sterilization Perform pressure and leakage tests and sterilization on newly installed water mains and altered water m ains prior to placing such pipelines into service. Provide all equipment, piping, controls, pumps, water and safety devices necessary for performing the tests and sterilization. Obtain clean water for cleaning, testing and sterilization from approved sour ces. Provide connections to potable water sources with approved backflow preventors until acceptance of all test results. Perform tests using clean water and provide certified results demonstrating leakage less than the following amount when pressurized a t 200 ± 5 psi for 2 hours. W = 000 , 148÷P LD Where: W = allowable leakage in gallons per hour L = length of pipeline tested, in feet D = nominal diameter of the pipe, in inches P = average test pressure during the leakage test, in lb/sq.in. Repair using approved methods or replace pipe, controls or appurtenances as necessary to reduce leakage below acceptable levels . Additionally, repair any leaks that are visible after 2 hours dur ation. Clean water lines by flushing with water at least 2.5 feet per second velocity. Remove all debris and dirt from water mains larger than 4 inches by passing a medium density foam pig with abrasive strips through the lines. Sterilize water lines in a ccordance with Section 1003 of the Rules Governing Public Water supply and AWWA C651 Section 4.4, the Continuous Feed Method. Provide a
Source: North Carolina Standard Specifications for Roads and Structures, 2024 Edition. Pages 731–732 of 857.