Category:1041 Polypropylene Culvert Pipe

This article establishes procedures for inspecting, accepting and reporting polypropylene culvert pipe. Refer to Sec 1041 for MoDOT’s specifications. Additional information on pipe, selection, inspection and payment can be found in Sec 724, Sec 730, EPG 724 Pipe Culverts and EPG 730 Corrugated Polyethylene Pipe Culverts.

1041.1 Construction Project Acceptance

Polypropylene culvert pipe is to be accepted for use on the basis of the pipe manufacturer being on the approved list and the supplier/manufacturer obtaining and providing pipe ID#s for each shipment/lot/size of pipe. A random sampling system is administered by Central Office construction and materials to ensure the quality and engineering properties of the pipe.

The supplier/manufacture of the pipe should get the ID#s prior to shipment using Pipe Shipping Report Form for reporting to the Central Office, GS-17 Form 1. When the ID#s are assigned by Central Office Construction and Materials, the supplier/manufacturer will be notified if the shipment has been selected for sampling. This gives the supplier/manufacturer an opportunity to ship extra pipe to the jobsite to ensure the sampling process does not leave the contractor short of material.

If the supplier/manufacturer of the pipe does not get the ID#s prior to shipment, Central Office Construction and Materials should be notified.

1041.2 Maintenance Acceptance

The need to assign ID#s and the random sampling process applies to pipes purchased for maintenance as it does for construction projects. Completion of the sample records for materials purchased under a MoDOT purchase order is to be as described in EPG 1101 Materials Purchased by a Department Purchase Order.

1041.3 Manufacturer Approval

Prior to supplying polypropylene culvert pipe, the manufacturer shall have furnished Central Office – Construction and Materials, a "Pipe Manufacturer's Certified Analysis" and "Pipe Manufacturer's Guarantee" as required by Sec 1041. The manufacturer shall specify in their application for placement on the qualified list which standard their pipe is fabricated to; English or metric. The manufacturer shall provide the definition of a lot or it will be considered one day’s production. See the list of Qualified Fabricators of Polypropylene Pipe for manufacturers who have filed acceptable documents.

If random sampling results in the rejection of the polypropylene pipe, acceptance on the basis of pipe manufacturer's certified analysis and guarantee may immediately be discontinued and all polypropylene pipe of that brand shall then be sampled, tested, and approved prior to use until such time as shall be determined by Construction and Materials. Construction and Materials will advise all districts should acceptance of a brand by pipe manufacturer's certified analysis and guarantee be discontinued. When test results again indicate consistent compliance to specification requirements, Construction and Materials will notify all districts to reinstate that brand to the approved list of manufacturers.

During any visit to the manufacturer, the manufacturer’s records shall be reviewed for test result and inspection documentation. The records shall be specific to each shipment of pipe, and shall indicate the purchase order number or project number, route, a county, date of inspection, quantity (ft. or m), and pipe diameter.

If a manufacturer is found not to be in compliance with the specifications, notify Construction and Materials so the manufacturer’s approval can be reconsidered. If the manufacturer is found falsifying documentation, Construction and Materials is to be notified immediately for removal of that manufacturer or plant from the approval list.

1041.4 Random Sampling

Random sample locations will be determined by Central Office Construction and Materials as approximately 10% of shipments statewide. The specific pipes determined for testing by Central Office will take into account the limitations of MoDOT’s laboratory testing equipment. The samples are to be obtained by the districts and submitted to the Laboratory for determination of physical properties. Samples may be taken at the point of manufacture, intermediate distribution point, or at the project. The sample shall consist of 2 specimens, each a minimum of one diameter in length plus two additional corrugations, not including the bell or the spigot ends. If the sample fails to meet the physical requirements, the pipe sampled will be rejected and the lot re-sampled. A resample will be the same number of specimens as the original sample. The resample must comply in all respects or the entire lot will be rejected.

1041.5 Field Inspection

When necessary, field inspection of the polypropylene pipe itself shall be performed using the Polypropylene (PP) Pipe Inspection Guide. For the purposes of field inspection, the definition of a lot shall be the entire quantity shipped.

Apparatus Needed:

1) Rule with suitable graduations to accurately measure the material to be inspected.

2) Micrometer capable of measuring to 0.0001 in. (0.00254 mm) and accurate to within at least 0.001 in. (0.0254 mm).

3) Polypropylene (PP) Pipe Inspection Guide.

The engineer may inspect the fabricated pipe at the manufacturing plant, intermediate distribution point, or project. The engineer shall have free access to the manufacturing plant or intermediate distribution point for inspection, and every facility shall be extended for this purpose. Any pipe, which has been previously rejected and included in a later lot, will be considered sufficient cause for rejection of the entire lot.

The standard fabrication units will be designated on the qualified list for each manufacturer. All measurements shall be made using the applicable units when determining compliance with specification.

The specified inside diameter, in accordance with applicable ASTM, should comply with the table below. Again, all measurements shall be made using the same units as to which the pipe was fabricated.

Pipe that has been rejected at the origin shall be marked with a small, filled circle or orange paint on the inside of the barrel, in the downstream end. The pipe is subject to inspection and rejection at destination for any damage that may have occurred in handling. Pipe that is rejected at destination shall be marked in the same manner as pipe rejected at the origin. The inspector may choose to mark inspected pipe to prevent inspection of the same pipe more than once. However, the “MoDOT OK” stamp should not be used.

If pipe is rejected for not being in accordance with specifications and the requirements set forth in the Polypropylene (PP) Pipe Inspection Guide, a letter documenting the failure shall be provided to the manufacturer, with a copy to Construction and Materials. The inspection guide used to inspect the rejected pipe shall be included with the letter to the manufacturer and Construction and Materials. The letter should include the location of the plant at which the failure occurred.

1041.6 Sample Record

When Central Office Construction and Materials issues ID#s, they will create the corresponding sample record for acceptance of the pipe.

When samples are taken by the districts, the inspector should create a sample record representing the sample.

When field inspection is performed by the district the results should be recorded in AASHTOWARE Project (AWP) by either adding the template and details to the original sample record created by Central Office or by creating a new sample record with a contract tab quantity of 0 to avoid double reporting the pipe.

Individual AWP sample records should be created for each size of pipe.

1041.7 Polypropylene Culvert Pipe Properties

Polypropylene pipe comes in two varieties under the MoDOT specifications; double wall and triple wall. Double wall PP is AASHTO M 330 Type S material with a smooth interior and a corrugated exterior. Triple wall PP is AASHTO M 330 Type D material with a smooth exterior, smooth interior, and an internal hidden corrugation forming the three walls. Please note that each type has different engineering properties and allowable fill heights.

1041.7.1 Identification Markings

Each pipe and fitting is to be clearly marked, in accordance with the applicable ASTM, at not more than 10 ft. (3 m) intervals by the manufacturer and the marking is to contain the manufacturer's name or trademark, nominal size, ASTM designation, the plant designation code, and the date of manufacture or an appropriate code.

1041.7.2 Internal Diameter Tolerances for Double Wall Pipe Table

1041.7.3 Internal Diameter Tolerances for Triple Wall Pipe Table