7-13-98

SLIP LINING OF ROADWAY CULVERTS WITH
POLYETHYLENE CULVERT PIPE LINER

    DESCRIPTION. This specification covers the requirements for high density polyethylene pipeliner for relining existing in-place concrete, vitrified clay, or metal culvert pipe and filling the annular space between the liner and the existing culvert with cellular grout. The Contractor shall furnish and install the liner and grout in accordance with 105.03.

MATERIALS

    MATERIALS. The materials used to manufacture the liner shall be high density high molecular weight polyethylene pipe material meeting the requirements of Type III, Class C, Category 5, Grade P34 as defined in ASTM D 1248. Clean rework material generated by the manufacturer's own production may be used so long as the liner produced meets all the requirements of the specification.

    The liner material shall be homogeneous throughout. The liner shall be free from visible cracks, holes, foreign inclusions, or other injurious defects. The liner shall be uniform as commercially practical in color, capacity, density, and other physical properties.

    The average nominal inside diameter of the liner shall be true to the specified liner size ± 6 mm (1/4 in.). Standard laying lengths shall be a minimum of 5.8 m (19 ft), but not exceed 12 m (40 ft) or as specified by the Engineer.

    The liner shall have a maximum n-factor of .012 and shall be capable of maintaining a minimum flow rate equivalent to 100 percent of the original in-place culvert. The liner shall have a Standard Dimension Ratio, SDR, equal to 32.5, or have a minimum pipe stiffness of 317 kPa (46 psi) when tested per ASTM D 2412 or be Class 160 type pipe in accordance with ASTM F 894. SDR is defined as the ratio of the liner outside diameter to the minimum thickness of the wall of the liner. SDR can be expressed mathematically as:

SDR = D
      t

    Where D = liner outside diameter in mm (in.)
          t = minimum liner wall thickness in mm (in.)

    Jointing the liner shall be by either bell and spigot, screw type, thermal welding, or a grooved press-on joint approved by the Engineer. The joint shall have sufficient mechanical strength to allow the liner to be installed through the existing pipe without affecting the joint's integrity. Jointing must provide water tight integrity for all joints. Jointing of the liner shall not interrupt the flow characteristics of the pipe.

    A 300 mm (12 in.) section of the liner shall show no evidence of splitting, cracking, or breaking when compressed between parallel plates to 40 percent of its outside diameter within 2 to 5 minutes. The liner shall have sufficient rigidity to withstand being placed by either pulling or pushing and shall exhibit a minimum amount of distortion.

    The manufacturer shall furnish certifications to the Division of Materials and Tests stating that the material used in the manufacture of the liner meets the requirements of ASTM D 1248 for the type, class, category, and grade specified. The manufacturer shall also certify that the finished liner is in compliance with this specification.

    The materials used to manufacture the cellular grout shall be in accordance with the following.

        Fine Aggregate.................904.01
        Fly Ash........................901.02
        Foam Concentrate...............ASTM C 796
        Water..........................913.01

    Admixtures, retarders, and plasticizers used shall be in accordance with the foam concentrate supplier's specifications. Portland Cement shall be in accordance with 901.01(b) except type II cement shall not be used.

    The grout shall be made using the preformed foam process using foam generating equipment calibrated by the foam manufacturer to produce a precise and predictable volume of foam. The foam concentrate shall be certified by the manufacturer to have specific liquid/foam expansion ratio at a constant dilution ratio with water.

    The specific job mix shall be submitted by the foam concentrate supplier certified grouting contractor to the Engineer for approval prior to use on the project. The mix shall have a minimum 28 day compressive strength of 1040 kPa (150 psi). The mix shall be tested and verified in accordance with these specifications or shall be approved based on prior acceptance and suitable performance on Department projects.

    Grout mixed off site shall be delivered to the job site in a truck mixer in accordance with 702.09 filled to half its capacity. The foam concentrate shall then be added to the cement mix in the truck and mixed to a uniform consistency.

    Grout mixed on site shall be batched in a deck mate or a similar device. Small batches of approximately 1 cubic meter (1 cubic yard) shall be mixed and pumped in a continuous operation.

    For each day worked or for each 100 cubic meters (100 cubic yards) placed, four test cylinders measuring 75 mm by 150 mm (3 in. by 6 in.) shall be cast. The cylinders shall be prepared, cured, and transported in accordance with ASTM C 31 and ASTM C 192. The cylinders shall be tested in accordance with ASTM C 39 except the test specimens shall be broken within the permissible tolerance prescribed as follows:

Test Age
24 g
3 days
7 days
28 days
Permissible Tolerance
±1/2 h
±1 h
±3 h
±12 h

    The cylinders shall be obtained from the point of placement.

    EQUIPMENT. All equipment necessary for the satisfactory performance of this work shall be approved by the Engineer. This equipment shall include all machinery necessary for the installation of the liner, grout and the reworking of the temporary easements.

    The equipment used to produce the grout, and all equipment used in the mixing, pumping, and placing shall be certified as to its suitability by the supplier of the foam concentrate.

    The Contractor supplying and placing the grout shall be certified by the foam concentrate supplier and shall be capable of developing a mix design, batching, handling, pumping and placing grout under the project conditions.

    RIGHT OF ENTRIES. All right of entries required for the work shall be acquired by the Contractor. All damage within these areas shall be repaired to original condition by the Contractor. Bare areas or areas having sod cover shall be seeded and mulched. All damaged fences shall be repaired by the Contractor. The Contractor shall install and maintain temporary fence as directed by the Engineer.

CONSTRUCTION REQUIREMENTS

    CONSTRUCTION REQUIREMENTS. The Contractor shall re-establish the flowline of any eroded inverts, as directed by the Engineer, with grout meeting the requirements as set out in the Standard Specifications. Pre-mixed grout may be used subject to approval of the Engineer. The Contractor shall maintain a positive flowline in the liner. Any obvious cavities under the existing pipe shall be filled with grout.

    After the liner has been completely inserted and has been inspected by the Engineer, it shall be cut off flush with the ends of the existing culvert or as directed by the Engineer. It shall then be grouted in place. If the liner has been exposed to the sun before the insertion is made, it shall be allowed to cool to the temperature of the existing culvert before it is cut off and grouted.

    Block and mortar bulkheads shall be placed at both ends of the culvert. A 50 mm (2 in.) vent hole at the crown and a 25 mm (1 in.) hole at the invert shall be placed in the downstream bulkhead. An access hole sized to facilitate the method of grout input and a 50 mm (2 in.) air vent shall be placed at the crown in the upstream bulkhead.

    The grout shall be placed from the upstream end of the culvert where practical. The vent holes in the downstream bulkhead shall be plugged as soon as grout begins to flow out each hole. The 50 mm (2 in.) air vent in the upstream bulkhead shall be kept clear until grout begins to flow out of it. It shall then be plugged.

    The grout shall be placed by either gravity flow or by low pressure pumping so as to completely fill all voids within the annular space without causing deformation of the liner. The grout shall extend for the full length of the culvert.

    Grout placed by gravity flow shall be limited to a maximum length of flow of ten feet for each foot of available head per access hole. Additional access holes, where required, shall be drilled from the top and sleeved with 150 mm (6 in.) pvc piping.

    Grout placed by low pressure pumping shall be done such that the maximum pressure developed in the cavity shall not exceed the liner manufacturer's recommendation for external pressure allowed. Additional access holes, where required, shall have a minimum diameter of 100 mm (4 in.) and shall be drilled from the top and sleeved with pvc piping.

    Liner storage areas shall be approved by the Engineer. All drainage structures and ditches shall remain open at all times. All traffic control shall be in accordance with the MUTCD or as directed.

    All liner sizes will be approved by the Engineer prior to installation.

    All incidental work, such as brush removal, flowline adjustments, etc., shall be accomplished by the Contractor. Where required, and practical, a bull nose device shall be pulled through the existing culvert to facilitate the liner installation. The bull nose device shall be of appropriate diameter to permit the installation of the intended liner size. The pipe shall be completely cleared of all foreign material just prior to the installation of the liner.

    METHOD OF MEASUREMENT. Polyethylene culvert pipe liner will be measured in accordance with 715.11. Grout will not be measured.

    BASIS OF PAYMENT. The accepted quantities of pipe, polyethylene liner will be paid for at the contract unit price per meter (linear foot) for the size specified complete in place.

    The cost of grout; flowline adjustments; brush removal; the grouting of cavities or the flowline of the existing pipe; the maintenance of traffic; of acquiring easements; the repair of damage to easements or fences including seeding and mulching; the furnishing, erection, and removal of temporary fence; and all other incidental work will be not be paid for separately but shall be included in the cost of pay item.

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