In addition to the requirements shown under the general listing procedures, the initial request for acceptance shall include  test data showing compliance with the requirements indicated below.

    Notes:

         1. Re-certification of a manufacturer's product shall be required every 2 years after initial acceptance of that product.
        
        2. ASTM D 1693, "Test for Environmental Stress-cracking of Ethylene Plastics", has been updated on
            August 10, 2001, to ASTM F 2136, "Standard Test Method for Notched Constant Ligament-Stress (NCLS) Test
            to Determine Slow-Crack Growth Resistance of HDPE Resins or HDPE Corrugated Pipe" (ASTM News,
            Oct.2001).

 

Performance criteria and test procedures for multi-duct concrete conduit

In addition to the requirements shown under the general listing procedures, the initial request for acceptance shall include test data showing compliance with the requirements indicated below.

1.      Multi-duct concrete conduit shall consist of a homogeneous mixture of PortlandCement, aggregates, and water.  Portland Cement shall be type I, II, or III conforming to ASTM C150-97, "Standard Specification for Portland Cement."

2.      Physical Test

(i)      Permeability.  No conduit shall be permeable to water in excess of 38.5 cubic in. (63.1*E+04 cubic mm) per hour as determined in an outside corner chamber of the multiduct.  The test specimens for this test shall be in units of conduit at least 36 in. (914 mm) in nominal length which have been dried at a temperature of approximately 70º F (21º C) for a period of not less than 24 hours.  A total of 5 test specimens shall be prepared in this manner.  A rubber duct plug or equivalent shall then be used to seal the chamber to be tested.  Water at a temperature of approximately 70º F (21º C) shall be poured into the sealed chamber to a height of 34 in. (864 mm) from the sealed end of the chamber.  The water level shall not fall more than 2 in. (51 mm) in 30 minutes for each of the tested specimens.

(ii) Compressive Strength.  Compressive strength tests shall be made on a total of 5 specimens of 12 in. (305 mm) in nominal length cut from full length units of conduit but not including any formed end.  Specimens shall be air dried at a temperature of approximately 70º F (21º C) for a period of not less than 24 hours immediately prior to the test.  Samples shall be tested, 6-duct resting on the wide side, as follows.  A suitable container, having interior dimensions of not less than 14 in. (356 mm) in length and 14 in. (356 mm) in width, shall be filled to a depth of not less than 2 in. (51 mm) nor more than 4 in. (102 mm) with dry, tightly packed sand and placed on the lower platen of the testing machine.  The test specimen shall be bedded on the sand so that its upper surface is parallel with the crosshead of the test machine.  The upper bearing block shall consist of a rigid steel plate 14 in. (356 mm) square and not less than 1/2 in. (13 mm) thick and shall be positioned so that it overhangs the flat portion of the upper surface of the sample on all sides.  A sheet of sponge rubber 1 in. (25 mm) thick and 14 in. (356 mm) square, or equivalent, shall be inserted between the bearing block and the specimen.  The load shall then be applied at a uniform rate such that the minimum compressive value is reached in not less than 1 minute. A sample shall be considered to have failed upon the first evidence that cracking has occurred below the minimum breaking load as specified for each size of conduit: 

 

All Epoxy Resin Fiberglass conduit and fittings shall be manufactured and tested in accordance with NEMA TC-14, "Filament-Wound Reinforced Thermosetting Resin Conduit and Fittings".  In addition to the requirements shown under the general listing procedures, the initial  request for acceptance shall include test results for all sizes of conduit to be considered for RUS acceptance.

Any further information or questions concerning acceptance procedures for conduit please contact the following: