SPECIFICATIONS

GLASS-FIBER REINFORCED POLYESTER (FRP) REHABILITATION WETWELLS

 

I. SCOPE OF WORK

  1. The contractor shall furnish all materials, labor and equipment for the installation of fiberglass reinforced polyester (FRP) wetwells and accessories including concrete sections as shown on engineers drawings and as specified herein.
     
  2. The FRP wetwells are underground vertical vessels described as "fiberglass cylinders" and require poured in-place reinforced concrete bases and reinforced concrete tops, unless otherwise specified. Pipe connections may be field installed or installed by manufacturer.
     
  3. These specifications are intended to give a general description of what is required, but do not purport to cover all the structural design details which may vary in accordance with the project requirements. It is, however, intended to cover the furnishing, shop testing, delivery, and complete installation of all fiberglass reinforced plastic structures specified herein.
     
  4. The supplier of the fiberglass manholes, wetwells, and accessory items shall coordinate his work with that of the Contractor so that the unit will be delivered and installed in the excavation provided by the Contractor, in accordance with the construction schedule.
     
  5. The top slabs, frames, covers, and subsurface FRP structures shall be capable of supporting the overburden plus the load requirements per the engineering specification.

 

II. GOVERNING STANDARDS

Wetwells shall conform to the following design criteria:

  1. ASTM C-581:Practice for Determining Chemical Resistance of Thermosetting Resins Used in Glass-Fiber Reinforced Structures Intended for Liquid Service
     
  2. ASTM C-582: Plastic Laminate
     
  3. ASTM D-695: Test Methods for Compressive Properties of Rigid Plastics
     
  4. ASTM D-2584: Test Method for Ignition Loss of Cured Reinforced Resins

 

III. SUBMITTALS

  1. A.Submit to Engineer shop drawings showing details of construction, reinforcing, and joints.
     
  2. Fabrication Drawings
    1. The fiberglass reinforced plastic (FRP) manufacturer shall furnish and submit for approval complete fabrication drawings and calculations for all structures. Fabrication of structure shall not proceed until submittal drawings are approved in writing by the Engineer and Contractor.
    2. All inserts, pipe sleeves, and other accessories required as indicated on the final approved drawings will be placed as shown and any omission or changes in location or details by the Contractor shall be done at his expense.
       
  3. Manufacturer’s Literature: Manufacturer’s recommended installation instructions.
     
  4. Manufacturer’s Certificates of material conformance with specifications.
     
  5. Test Reports: The fiberglass manufacturer shall design, fabricate and certify that the fiberglass cylinders conform to ASTM D-3753 and to the requirements of this specification.

  

IV.PRODUCTS: FIBERGLASS REINFORCED POLYESTER WETWELLS DIAMETERS (I.D.): 36", 42", 48", 54", 60", 66", 72", 92", 120"

  1. GENERAL DESCRIPTION: Fiberglass Reinforced Polyester wetwells, shall be cylinders made of composite laminate. The laminate shall consist of thermo-setting chemical resistant polyester resin, fiberglass reinforcement, and additions as required. Structures shall be sized on the plans for the applicable stations. Wetwells, shall be manufactured by Containment Solutions, Inc., (Conroe, Texas FRP Wetwells) or Engineer pre-approved equal.
     
  2. GOVERNING SPECIFICATIONS: The following specifications are applicable for materials, workmanship, and reference.
    1. AWWA C 950 "Glass-Fiber Reinforced Thermosetting Resin Pressure Pipe".
    2. ASTM C-581 "Practice for Determining Chemical Resistance of Thermosetting Resins Used in Glass-Fiber Reinforced Structures Intended for Liquid Service"
    3. ASTM C-582 "Plastic Laminate"
    4. ASTM D-695 "Test Methods for Compressive Properties of Rigid Plastics"
    5. ASTM D-2584 "Test Method for Ignition Loss of Cured Reinforced Resins"
       
  3. MANUFACTURER’S QUALIFICATIONS: The manufacturer of the wetwell shall be able to show experience in the manufacture of FRP wetwells for more than five years.
     
  4. DESIGN CRITERIA:
    1. Wetwells shall withstand lateral hydrostatic pressure (assume water to grade) with a minimum safety factor of 2.5.
    2. The wetwells, shall be suitable for use in typical environments including storm, industrial, and sanitary sewers with a temperature range of -40° F. to 150° F.
    3. Cylinders shall be designed and fabricated to provide sufficient strength for the following loading conditions:
      1. Resistant to buckling when empty and when the groundwater elevation is at grade.
      2. The anchoring wall structure at the embankment within the reinforced concrete base zone shall be designed to resist external hydrostatic water forces of an empty or full cylinder with the groundwater at grade elevation.
      3. Load Bearing Capacity: Properly installed wetwell shall be capable of withstanding H-20 dynamic loading (16,000 lbs.) applied vertically.
    4. The FRP wetwells, shall be manufactured to the diameters and heights as shown in the plans and specifications. They shall be designed by the manufacturer to perform as underground structures at the depths required and to withstand the necessary lateral pressures with minimum factor of safety of 2.5. The FRP structures shall be capable of supporting the top slab covers, frames, soil overburdens plus a live load equivalent to AASHTO H-20 Loading.
    5. All cutouts shown in the plans and details for each FRP wetwell shall be capable of maintaining the unit’s structural integrity.
    6. Wetwell FRP Tops and Hatch Openings: Resin and glass fiber reinforced wetwell tops and hatch openings may be provided upon Engineers request. Wetwells shall be provided with glass reinforced top designed to withstand backfill and concrete slab. Fiberglass Ribs or Fiberglass structural members may be utilized to meet the design criteria. Stiffeners shall be of non-corrosive materials encapsulated in fiberglass. FRP encapsulated wood or lumber shall not be permitted.
      Hatch opening dimensions to be specified by Engineer. Lip on hatch opening shall be 2" or 4" tall. Rectangular or square opening shall be constructed of fiberglass.
    7. Wetwell FRP Bottoms: Resin and glass fiber reinforced wetwell bottoms may be provided upon Engineers request. Upon that request, wetwells shall be provided with glass reinforced bottom section designed to withstand the hydrostatic head pressure, empty and water to grade, of units at 25-ft. burial depth. (Units deeper than 25 ft may require additional reinforcement as required). Fiberglass Ribs or Fiberglass structural members may be utilized to meet the design criteria. Stiffeners shall be of non-corrosive materials encapsulated in fiberglass. FRP encapsulated wood or lumber shall not be permitted.
      Bottoms sections shall be furnished with an intregal 3" wide anchoring flange.
    8. Wetwell FRP bottom or top flanges: Resin and glass fiber reinforced wetwell flanges may be provided upon Engineers request. Flanges shall be 3" wide minimum.
       
  5. Marking and Identification: All Wetwells shall be marked in letters no less than 1" in height with the following information:
    1. Manufacturers Identification
    2. Manufacturers Serial Number
    3. Wetwell Diameter & Length
    4. ASTM Designation

 

V.MATERIALS:

  1. Resin:Unsaturated isophthalic polyester resins shall be used and they must meet the requirements listed below.
     
    Property Test Method Requirement
    a. Acid Number ASTM D 465-59 Maximum = 15
    b. Hydroxyl Number Maximum = 30
    c. Solids Content ASTM D 1259-61 Maximum = 50%

    The following requirements are determined when testing the resin without any reinforcing material included.
     
    Property Test Method Requirement
    d. Flexural Strength ASTM D 790-70 Minimum 10,000 psi
    e. Flexural E-Modulus ASTM D 790-70 Minimum 400,000 psi
    f. Elongation at Rupture ASTM D 790-70 Minimum 2-1/2%
    g. Heat Distortion Temperature ASTM D 648-61 Minimum 167° F
    h. Weight Change after 28 Days Storing in Distilled Water ASTM D 570-63 Maximum +150 mg/sample
    i. Surface Hardness (Barcol) ASTM D 2583-67 Minimum 80% of Resin’s Normal Value

    The same supplier shall supply all resin. Mixed lots or "odd lots" of resin from different vendors shall not be used.
     
  2. Reinforcement: Reinforcement shall be fiberglass mat, continuous roving, chopped roving and/or roving fabric. The fiberglass shall be type "E" and have a finish compatible with the resin used.
    The interior surface shall be reinforced layer 0.25 mm. to 0.50 mm. (10 to 20 mils.). Reinforcement materials shall be:
    1. Chemically resistant surface mat
    2. Organic surfacing veilReinforcements must have a coupling agent that will provide a suitable bond between the reinforcement and the resin.
        
  3. Fillers: Fillers, when used, must not degrade the resin chemical resistant properties as defined in this specification.
     
  4. Additives: Additives, such as thixotropic agents, catalyst and promoters may be added as required by the specific manufacturing processes used to meet this standard. However, calcium carbonate mixed by the manufacturer shall not be permitted. The resulting reinforced plastic material must meet the requirement of this specification.
     
  5. Laminate: (Cured composite including glass fiber reinforcement.) Cured laminate must meet the following conditions:
     
    Property Test Method Requirement
    a. Glass Content (% by wt.) ASTM D 2584-68 20 to 70%
    b) Compressive Strength D 695-69 Minimum 12,000 psi
    c) Flexural Strength D 790-70 Minimum 12,000 psi
    d) Flexural E-Modulus ASTM D 790-70 Minimum 700,000 psi
    e) Surface Hardness ASTM D 2583-67 Minimum 90% of Resin’s Normal Value

     
  6. UV Inhibitors/stabilizers shall be added directly to resins system to prevent photodegradation of laminate. Exterior gel-coating or painting shall not be permitted.

 

VI.QUALITY ASSURANCE/QUALITY CONTROL

  1. Examination: Each FRP cylinder component part shall be examined for dimensional requirements, hardness and workmanship.
     
  2. Composition Control: Controls on glass and resin content shall be maintained for all manufacturing processes and for each portion of the FRP cylinder fabrication. Records shall be maintained of these control checks. Proper glass content my be shown by glass usage checks, by glass and resin application rate checks, in accordance with the material composition test in ASTM D 3753, Section 8.8.1.
     
  3. All required ASTM D-3753 testing shall be completed and records of all testing shall be kept and copies of test results shall be presented to customer upon written request within a reasonable time period.
     
  4. When requested by the purchaser on his order, a certification shall be made the basis of acceptance. This shall consist of a copy of the manufacturer’s test report or a statement by the supplier, accompanied by a copy of the test results, that the FRP cylinders have been sampled, tested, and inspected in accordance with the provisions of ASTM 3753 and the requirements of this specification. An authorized agent of the supplier and manufacturer shall sign each certification so furnished.
     
  5. Rejection of Manholes/Wetwells: Manholes/Wetwells are subject to rejection on account of any of the following visual defects:
    1. Fuzz: Glass fibers loosely adhering to manhole, which are not wet out with resin.
    2. Protruding Fibers: Glass fibers sticking out from pipe surface that is not wet out with resin.
    3. Resin Runs: Runs of resin and sand on surface of manhole.
    4. Dry Areas: Areas in laminate with glass to wet out with resin.
    5. Delamination: Separation in the laminate.
    6. Blisters: Light (straw) colored areas resulting from too hot a cure.
    7. Craze: Crack usually star shaped; caused by sharp impact.
    8. Surface Pits or Voids: Small air pockets on the surface or directly beneath the surface mat.
    9. Wrinkles: Smooth irregularities on the surface.
    10. Torn Edges, End Delamination and End Gauges: Tears and rips in the edge of cuts.
    11. Ground Area: Areas around lay-up, which have been abraded and not covered by lay-up.
    12. Hand Lay-up Ragged Edges: Areas at the edge of hand lay-up that are not rolled down properly and that are rough.
    13. Painting or gel-coating of exterior or interior laminate.

 

VII. HANDLING AND STORAGE REQUIREMENTS

  1. FRP wetwells shall be lifted by the installation of lifting lugs as specified by the manufacturer on the outside surface near the top or by a sling or choker connection around center. Use of chains or cables in contact with the wetwell surface is prohibited. Wetwells may be lifted horizontally using one support point. Wetwells may be lifted horizontally using one support point.
     
  2. FRP wetwells may be stored upright or horizontally, however, the wetwell vertical deflection shall not exceed 4% of the diameter. The wetwell shall not be dropped or impacted.
     
  3. Additional handling and installation instructions shall be in accordance with the FRP manufacturer’s instructions.
     
  4. Each FRP section manufactured in accordance with the drawings shall be clearly marked to indicate the intended pump station installation location. The contractor shall be responsible for the installation of the correct FRP sections in their designated pump station locations. 

 

VIII. INSTALLATION METHODS

  1. Each excavation and backfill are to be done as part of the work under this section, including any necessary sheeting and bracing. The contractor shall be responsible for handling groundwater to provide firm, dry subgrade for the structure, shall prevent water from rising on new poured in place concrete within 24 hours after placing, and shall guard against flotation of other damages resulting from groundwater or flooding.
     
  2. A minimum of 12-in. bedding shall be placed as a foundation for the wetwell base slabs.
     
  3. Backfilling: Do not backfill until concrete base has hardened sufficiently to provide rigid support for both the wetwell and backfill. Add backfill evenly in 12" lifts all around wetwell to avoid uneven backfill loads. 90% compaction of backfill is required in order to prevent settlement of connecting pipes and to provide sidewall support to the wetwell.
     
  4. The Cast-in-place concrete base, shall be placed on a thoroughly compacted sub-base. The bottom of the FRP sections shall be cast-in-place a minimum of 4 inches and shall be adjusted in grade so that the top slab section is at elevation specified in the contract or on approved drawings.
     
  5. Pre-cast concrete bases are permitted with Engineer pre-approval for installation with the wetwell. If such bases are used and are to be set with the wetwell, all lifting shall be done on the base itself with Engineer approved lifting eyes or loops and not the wetwell structure.
     
  6. The FRP manufacturer’s written installation instructions shall be followed to ensure the wetwell will perform in accordance with the design requirements of the applicable specification.
     
  7. Wetwell cutouts may be made in the FRP wetwell, using a circular saw, saber saw, hole saw, or similar equipment with a masonry type blade. Axes, hammers, chisels, or similar impact type tools may not be used.
     
  8. Stubouts and Connections: All FRP inserts and FRP sleeves for piping shall be made as shown on installation drawings and in accordance with the manufacturer’s FRP specifications for installation. Other methods of connections may be performed per Engineers request or as shown in the plans and specifications, i.e., Inserta-Tee fittings, pipe connectors which conform to ASTM C-923 or PVC sewer pipe with FRP lay-up reinforcement installed per manufacturer’s recommendation.
     
    1. Inserta-Tee Fittings: Joints for sewer pipe line and drop connections sizes 4" - 15" shall be made by means of Inserta-Tee watertight compression connection. Installation shall be in strict accordance with manufacturer’s written instructions utilizing installation equipment approved for use by the manufacturer of the Inserta-Tee fitting. Use of equipment which does not meet this requirement is expressly prohibited. Inserta-Tee Fitting a product of Fowler Mfg. Co., Hillsboro, OR.
       
    2. Pipe Stubouts:
    1. Install rubber gasketed PVC sewer pipe stubouts to wetwell with resin and glass-fiber reinforced lay-up. Gaskets shall meet the same performance requirements of the sewer pipe to be installed unless otherwise directed by Engineer. Resin and glass shall be of the same type and grade as used in the fabrication of the FRP wetwell.
    2. Install PVC or FRP pipe stubouts for use with resilient pipe-to-wetwell connectors (boots) which conform to the performance requirements of ASTM C-923. PVC or FRP pipe stubouts may also be used by placing incoming service piping through stubout and sealing the annular space with expandable sealing mechanism, such as "Inter-Lynx". Inter-Lynx is a product of Advanced Products and Systems, Inc., Lafayette, LA.

  

IX. INSPECTION

  1. The quality of all materials, the process of manufacture, and the finished sections shall be subject to inspection and approval by the Engineer, or other representative of the owner. Such inspections shall be made at the place of manufacture, or at site of delivery, and the sections shall be subject to rejection on account of failure to meet any of the specification requirements as specified herein. Sections rejected after delivery to the job site shall be marked for identification and shall be removed from the job at once. All sections which have been damaged after delivery will be rejected, and if already installed shall be acceptable if repaired or removed and replaced at the contractor’s expense.
     
  2. At the time of inspection the material will be examined for compliance with the requirements of this specification and the approved drawings.

 

X. MEASUREMENT

This item will be measured will be measured by each type of individual structure completed. The depth will be measured from the flow line to the top of the rim. The size shall be nominal inside diameter. This item includes, but is not limited to the following:

  1. Structural excavation
     
  2. Loading, hauling, and disposing of all excess material
     
  3. Furnishing all labor and materials including fiberglass, concrete, mortar, bricks, drop pipe and fittings, manhole rings and covers
     
  4. Placing and compacting all backfill
     
  5. Final Grading

 

XI. PAYMENT

  1. This item will be paid for at the contract unit price per bid per each structure for the various sizes, types, and various depths of structures complete in place and will be full compensation for all materials required, operations, labor, tools, equipment, and all other incidentals necessary to complete the work as shown on the drawings and specified herein.

 

Copyright © 1999 Containment Solutions, Inc.