Section 4143. �Subdrain Pipe

4143.01���� general requirements.

Use the size and type shown in the contract documents. When not designated, meet the following requirements:

A.��� Pipe for Horizontal Drains.

Use plastic pipe complying with the requirements of ASTM D 1785, Schedule 80. Comply with the following:

1.���� Unless specified otherwise, 3 rows of slots, 0.010 inch � 0.005 inch (254 �m � 127 �m) wide, on 120 degree centers around the circumference.

2.���� Minimum of 0.75 square inch (1588 mm²) of slot opening per linear foot (meter).

3.���� Provide with a suitable cap at the inlet end. Obtain Engineer�s approval for caps and couplings.

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B.��� Pipe for Longitudinal Subdrains.

1.���� Use perforated corrugated PE tubing and fittings manufactured and marked according to AASHTO M 252 with the following modification:

Use tubing perforated with slots according to AASHTO M 252. Circular perforations will not be approved.

2.���� Outlet subdrains using one of the following options:

a.���� Corrugated metal pipe meeting the requirements of Article 4141.01, including tapered ends when required.

b.���� Corrugated PE pipe, type S, approved per Materials I.M. 443 Appendix A, Part B.

c.���� Corrugated PVC pipe, Type S, approved per Materials I.M. 443 Appendix A, Part C.

3.���� When special connections are required for subdrain outlets, they will be detailed in the contract documents.

4.���� Cover outlet with a rodent guard meeting the requirements of Materials I.M. 443.01. Attach as shown in the contract documents. Engineer will inspect and accept according to Materials I.M. 443.01.

C.��� Standard Subdrains.

1.���� Use one of the following:

� Subdrain meeting the requirements of AASHTO M 196/M 196M or M 36/M 36M Type I or Type III.

� Drain tile (Section 4148) or Plastic Pipe (Section 4146).

� Polyethylene tubing meeting the requirements of Article 4143.01, B.

2.���� If furnishing subdrains that comply with AASHTO M 196/M 196M, use a specified sheet thickness of 0.048 inch (1.22 mm) for 6 inch (150 mm) diameter and 0.060 inch (1.52 mm) for larger diameters. If furnishing subdrains that comply with AASHTO M 36/M 36M, use a specified sheet thickness of 0.052 inch (1.32 mm) for 6 inch (150 mm) diameter and 0.064 inch (1.63 mm) for larger diameters.

3.���� Use perforated subdrains only when specified. As an option, AASHTO M 36/M 36M subdrains may be perforated with slots formed on the outside crests of helical corrugations, approximately 1 inch (25 mm) in length and 0.1 inch (2.5 mm) in width, spaced at 2 inches (50 mm) on centers.

4.���� When corrugated steel subdrains are specified, coated subdrains may also be specified. If so, ensure the coating complies with Article 4141.02.

5.���� If using plastic pipe meeting the requirements of ASTM F 758, D 3034, or D 2751, ensure perforations are as specified in ASTM F 758. Plastic pipe meeting the requirements of ASTM F 949 with slots may also be used.

6.���� If embedding the subdrain in granular or porous backfill material, use slotted plastic pipe meeting the requirements of ASTM F 949 or perforated, corrugated polyethylene (PE) tubing meeting the requirements of Article 4143.01, B.

D.��� Patch Subdrains.

Follow requirements for Article 4143.01, B, except that subdrain outlets will not be required.