606.01 Description.
3.Item 605- C. Special Underdrain Pipe will be paid for at the contract unit price, which shall be full compensation for all materials, equipment, tools, and labor required the installation of the pipe. The unit price shall include the furnishing of all pipe, fittings, and misce llaneous materials, excavation of the trench, installation of all materials, backfilling of the trench, disposal of excess materials, and for all incidentals necessary to complete this item of work.
b.Payment will be made under Item No .: 605-A Pavement * Drain - per linear foot {meter} 605-B Special Underdrain Outlet, Type _____ - per each 605-C Special ____ inch {mm} Diameter Underdrain Pipe - per linear foot {meter} * Median or Edge PIPE UNDERDRAIN
606.01 Description.
This Sectio n shall cover the work of furnishing pipe underdrain of the type and sizes provided on the plans or in the proposal in accordance with the requirements of these specifications, and installing such pipe at the locations sh own on the plans or designated and in substantial conformity with the established lines and grades. The work shall include the furnishing and construction of such joints and connections to other pipes, catch basins, endwalls, etc., as may be required to co mplete the work, as shown on the plans or directed, together with filter material and filter fabric as shown on Standard Drawing PU -606. Designations for the various types of pipe shall be as follows: Type Kind Abbreviations 1 Concrete Pipe C.P. 2 Corrugated Steel C.S. 3 Coated Corrugated Steel C.C.S. 4 Vitrified Clay V.C. 5 Corrugated Aluminum C.A. 6 Coated Corrugated Aluminum C.C.A. 7 Bituminous Fiber B.F. 8 Poly (Vinyl Chloride) P.V.C. 9 Acrylonitrile Butadiene Styrene A.B.S. 10 Polyethylene P.E. Unless specific types of pipe are specified by the plans or proposal, the Contractor may, at his option, use any of the approved types provided herein. However, an installation once started shall have the same type pipe unless otherwise noted in the plans or directed in writing.
606.02 Materials.
Materials shall meet the requirements specified in Section 852, Underdrain Pipe, including filter material. The geotextile filter for aggregate filled underdrain shall meet the requirements shown on the plans and shall be a non -woven material meeting the requirements of AASHTO M 288 for Class 2 Subsurface Drainage Geotextile and Section 810 of these specifications. The geotextile shall be selected from List II -3 of the “Materials, Sources, and Devices With Special Acceptance Requirements” manual. Information concerning this list is given in Subarticle 106.01(f) and ALDOT -355. All materials will be subject to further inspection for acceptance as to condition at the latest practicable time the Engineer has the opportunity to check for compliance prior to or during incorporation of materials in the work.
606.03 Construction Requirements.
a.Standard Pipe Installation . Trenches shall be excavated to the dimensions and grad e required by the plans or as directed. A minimum 3 inch {75 mm} bedding layer of filter material of the size shown on the plans shall be placed in the bottom of the trench for its full width and length and compacted as directed.
606.05 Basis of Payment.
Exposure of geotextile to the elements between lay down and cover shall be a maximum of 10 days to minimize the potential for damage. The geotextile filter shall be installed in such a manner that all splice joints are provided with a minimum overlap of 3 feet {1 meter}. Securing pins shall be installed to anchor the filter fabric if the geotextile material does not remain in place during the construction of the drains. Where seams are required in the filter fabric in the longitudinal trench direction, they shall be joined by either sewing or overlapping as outlined in Article 608.05 of these specifications. All seams shall be subject to the approval of the Engineer. Overlapped seams shall have a minimum overlap equal to the width of the trench and shall be anchored with securing pins as directed to insure the required overlap is maintained. Where a filter fabric repair is required, a piece of filter fabric shall be placed over the damaged area and extend 3 feet {1 meter} beyond the perimeter of the tear or damage. When an outlet p ipe passes through the filter fabric, a separate piece of filter fabric of sufficient size shall be wrapped around the pipe and flared against the side of the filled drain filter. Care shall be taken during the aggregate filler placement operation as well as the pipe installation to prevent damage to the filter fabric. The aggregate filler shall be placed and compacted by methods acceptable to the Engineer. Subdrainage pipe of the type and size specified shall be embedded firmly in the bedding material. Perforated pipe shall normally be placed with the perforations down, and the pipe sections shall be joined securely with the appropriate coupling fittings or bands. Non-perforated pipe shall be laid with the bell end up- grade and with open joints, wrapped with acceptable material which will permit entry of water, yet prevent loss of filter material. Up -grade ends of all subdrainage pipe installations shall be closed with suitable plugs to prevent entry of soil materials. After the pipe installation has been inspected and approved, filter material meeting the requirements of Article 852.10 shall be placed as specified on the plans to a minimum height of 12 inches {300 mm} a bove the top of the pipe. Care shall be taken not to displace the pipe or the covering at open joints. The remainder of the filter material shall then be placed and compacted to the required height. Any remaining portion of trench above the filter material shall be filled with granular or impervious material, as may be directed, and thoroughly compacted, consistent with the location of the trench within the work.
b.Underdrain Outlets . Trenches for underdrain outlets shall be excavated to the width and depth shown on the plans. Pipe shall be laid in the trench with all ends firmly joined by applicable methods and means. Perforated pipe shall be laid with holes up and covered with roofing paper, or non -perforated pipe meeting the same requirements of the per forated pipe may be used. After inspection and approval of the pipe installation the trench shall be backfilled with suitable soil in layers and compacted as provided for drainage pipe. Filter material will not be required for outlet trenches unless specif ied on the plans, or ordered by the Engineer.
606.04 Method of Measurement.
The accepted length of pipe underdrain, complete in place, of each specified size and type will be measured in linear feet {meters} along the center of each line or lateral, center to center of junctions and fittings.
606.05 Basis of Payment.
a.Unit Price Coverage .
1.The accepted quantity of each kind and size of pipe underdrain will be paid for at the contract unit price for pipe underdrain, complete in place for a depth of 3 feet {1 m eter} and less below existing ground line to bottom of trench which shall be payment in full for all excavation and its disposal, foundation preparation, backfilling, furnishing, hauling and placing of all materials including fittings, cutting for c onnections, joint material, bands, geotextile filter fabric, and aggregate filter material (or cover and bedding layer materials.)
2.Accepted quantity of pipe underdrain complete in place at depths greater than 3 feet {1 m eter} below the ground line shall have an adjusted unit price, arrived at by increasing the contract price bid by the percentage indicated in the table below. The unit price coverage provided in Item 1 above shall govern for such adjusted unit price.
607.01 Description.
Depth Underdrain Installed Below Existing Ground Line Extra Percentage Contract Unit Price Bid to be Increased More than 3 feet {1 m eter}, but less than 6 feet {2 m eter} 20 6 feet {2 m eter} and more, but less than 9 feet {3 m eter} 50 9 feet {3 m eter} and more, but less than 12 feet {4 m eter} 75 12 feet {4 m eter} or more 100
3.No separate payment will be made for excavation. The provisions of Article 214.04 are not applicable to this Section.
b.Payment will be made under Item No .: 606-A ___ inch {mm} Underdrain Pipe, Type * - per linear foot {meter} * Note specific type or types of pipe if required. See Article 606.01 for approved types. SECTION 607 PAVING GEOTEXTILES
607.01 Description.
a.General . This section shall cover the work of furnishing and placing a geotextile between pavement layers for the purpose of incorporating a waterproofing and stress relieving membrane within the pavement structure. This specification is applicable to geotextile membranes used for full coverage of the pavement, or as strips over transverse and longitudinal pavement joints. It is not intended to describe membrane systems specifically designed for pavement joints and localized (spot) repairs.
607.02 Materials.
a.Paving Geotextiles . The geotextiles u sed in this work shall be constructed of non -woven synthetic fibers meeting the requirements of AASHTO M 288 for Paving Fabric, Type II , and Section 810 of these specifications. The geotextile shall be selected from List II -3, of the Department's manual ti tled "Materials, Sources, and Devices With Special Acceptance Requirements". Information concerning this list is given in Subarticle 106.01(f) and ALDOT -355.
b.Asphalt Sealant . The material used to impregnate and seal the geotextile, as well as bond it t o both the base pavement and overlay, shall be a paving grade asphalt recommended by the geotextile manufacturer and approved by the Engineer. Cutbacks and emulsions which contain solvents shall not be used. Uncut asphalt cements or cationic and anionic e mulsions may be used provided these emulsions are used as outlined in Article
607.04 of these specifications.
c.Aggregate . If the ambient temperature is high enough to cause a bleed -through of the asphalt sealant, washed concrete sand may be spread over asphalt -saturated geotextiles to facilitate movement of equipment during construction or to prevent tearing or delamination of the geotextile. Excess quantities shall be removed from the geotextile prior to placing the surface course. A hot asphalt mix bro adcast in front of construction vehicle tires may also be used.
607.03 Equipment.
a.Asphalt Distributor . The distributor shall be capable of spraying the asphalt sealant at the prescribed uniform application rate. No streaking, skipping, or dripping will be permitted. The distributor shall also be equipped with a hand spray having a single nozzle and positive shut -off valve.
b.Geotextile Handling Equipment. Mechanical or manual laydown equipment may be used provided the laydown is smooth and without wri nkles or creases.
Source: Alabama Standard Specifications for Highway Construction, 2022 Edition. Pages 481–482 of 934.