Conduit
Article 1 — Description
Furnish and install intelligent transportation system ( ITS) multi- duct conduit identified for fiber optic communication use of the type and size specified. Provide conduit suitable for installation in an outdoor underground environment , including constant immersion in water, mounted to retaining walls, and mounted above ground on the underside of a bridge without any degradation to the conduit .
Article 2 — Materials
Provide new materials that comply with the details shown on the plans, the requirements of this Item, and the requirements of the following Items. Item 400, “Excavation and Backfill for Structures” Item 401, “Flowable Backfill” Item 402, “Trench Excavation Protection” Item 421, “Hydraulic Cement Concrete” Item 445, “Galvanizing” Item 476, “Jacking, Boring, or Tunneling Pipe or Box” Item 618, “Conduit” Item 620, “Electrical Conductors ” Furnish ITS m ulti-duct conduit from new materials in accordance with DMS -11035 , “Intelligent Transportation System (ITS) Multi -Duct Conduit .”
Article 3 — Construction
3.1 Underground Construction. Place conduit in conformance with the lines, grades, details, and dimensions
shown on the plans or as directed. Maintain constant slope to prevent water from being trapped in the conduit system. Ream all conduit ends to remove burrs and sharp edges. Install underground conduit system a minimum of 42 in. from ground surface to the top of the conduit unless otherwise directed or to avoid utility conflicts or field conditions. When conditions require trench depths greater than 5 ft., provide trench protection in accordance with Item 402. Install conduit in accordance with the NEC and the United States Department of Agriculture Rural Utilities Service. Fit the conduit terminations with bushings or bell ends with duct plugs. Seal inner ducts with duct plugs within 24 hr. of conduit placement. This includes but is not limited to intermediate or incomplete sections of conduit system before conduit splicing or termination in ground boxes. Document Global Positioning System (GPS) coordinate points, in North American Datum of 1983 (NAD83), and provide to the Department for shifts or deviations of the ITS multi -duct alignment from the plans required to avoid obstructions or utilities. Record GPS coordinate points at the point of curvature and point of tangent for horizontal of vertical transitions and include installed depth. Ensure a watertight seal of conduit to structure wall when terminating conduit. 862 Install markers using a method that firmly and securely anchors the marker a minimum of 1 ft. into the ground to prohibit twisting and easy removal. When located at an ITS ground box, marker may be placed within the concrete riprap apron avoiding rebar reinforcement. Spacing between markers should not exceed 1,000 ft. or as shown on the plans , and markers should be placed at significant changes in direction, such as a 90° turn. Do not place markers i n any roadway paved surface.
3.1.1 Proofing. Before installation of cables or final acceptance, pull a spherical template having a diameter of not
less than 75% of the inside diameter of the inner duct through the inner duct to ensure that the inner duct is free of obstruction. At the conclusion of proofing, fit ends of all empty inner ducts with duct plugs or caps within 24 hr.
3.2 Trench Construction. Provide minimum Schedule 40 polyvinyl chloride (PVC) conduit when conduit is
installed by trenching method unless otherwise shown on the plans or as directed. Provide a 2- in. minimum layer of sand at the bottom of the trench to serve as bedding material for construction. Provide conduit spacers made of a non- metallic material designed for installation underground and encased in concrete. Spacers should be of the type recommended by the conduit manufacturer and designed with an interlocking device, and stackable to relieve the conduit of both horizontal and vertical stress. Provide spacers sized appropriately for the conduit with a minimum height of 2 in. spaced at 5- ft. intervals throughout the trench. Set conduit spacers directly on the sand bedding. Spacers must be anchored to prevent floating of conduit system and maintain constant slope. Conduit system will be encas ed in the following materials based on depth of trench.
3.2.1 Greater t han 24 in. For trench depths greater than 24 in. from the ground surface to the top of the ITS multi -
duct conduit , encase the conduits in flowable fill to an elevation of 6 in. above the top of conduit in accordance with Item 401, or Class B concrete, maximum aggregate size 5, in accordance with Item 421. Use of Class B concrete will be at the Engineer’s discretion and as shown on the plans. Backfill above encasement as defined in Section 619. 3.2.3., “Excavation and Backfill.”
3.2.2 Less than 24 in. When a trench depth less than 24 in. is required, encase the conduits in Class B concrete,
maximum aggregate size 5, to an elevation of 6 in. above the top of conduit in accordance with Item 421. Backfill above encasement as defined in Section 619.3.2.3., “Excavation and Backfill.”
3.2.3 Excavation and Backfill . Trench, excavate , and backfill as shown on the plans and in accor dance with
Item 400.
3.2.4 Marking Tape . Place a 4 -in. wide detectable underground metalized M ylar conduit marking tape over the
ITS conduit at a minimum depth of 1 ft. below grade when no other electrical marking tape is required, or 8 in. below electrical mark ing tape when provisioned under Item 618. Imprint the marking tape “ TxDOT Conduit and Fiber Optic Cable System —Call TxDOT Before Proceeding” every 18 in.
3.2.5 Restoration of Trench Areas. Where existing surfacing is removed for placing conduit, repair by backfilling
with material equal in composition and density to the surrounding areas and by replacing any removed surfacing, such as asphalt pavement or concrete riprap, with like material to equivalent condition in accordance with Item 400.
3.3 Boring Construc tion. Jacking and boring when required will be in accordance with Item 476.
When boring under pavement shallower than 48 in. from finished grade to top of conduit, provide Schedule 40 steel casing under pavement to encase the conduit system as shown on the plans unless otherwise directed. Provide steel casing of a size to accommodate all conduits in addition to 20% space 863 capacity for pulling conduits through the steel casing. Steel casing will be furnished in accordance with this Item. During boring operati on, locate bore head every 10 ft. along the bore path and before traversing underground utilities or structures. Use digital walkover locating system to track bore head during boring operation. Ensure locating system can determine pitch, roll, heading, depth, and horizontal position of the bore head, and document this information at the intervals specified above for as -built information.
3.4 Above Ground Construction. Place conduit in conformance with the lines, grades, details, and dimensions
shown on the plans or as directed. Maintain constant slope to prevent water from being trapped in the conduit system. Provide rigid metal conduit or fiberglass conduit for outer duct when system is mounted externally along a bridge or above ground structure. Provide fiberglass or other non- corrosive outer duct for coastal Districts where conduit is exposed to corrosive environments due to salt in the air. Provide rigid metal conduit outer duct that is hot -dip galvanized in accordance with Item 445. Ground rigid metal condui t in conformance with the Department’s Electrical Details and in accordance with the NEC. Provide fiberglass conduit that is bullet resistant, heavy walled, pure, high grade, reinforced thermosetting resin conduit. Provide conduit, elbows, and fittings that are manufactured from the same resin, hardener, or glass systems manufactured by the same filament wound system. Use conduit expansion fittings at structure expansion joint crossings. Fasten all external conduit placed on structures using conduit straps or hangers as shown on the plans or as directed. Conduit straps, hanger systems, and junction boxes are incidental to this Item.
3.5 Testing . Perform tests in conformance with industry testing requirements identified in Article 619.2.,
“Materia ls.”
3.5.1 General . Furnish certified documentation from an independent testing laboratory documenting compliance
with all ASTM, NEMA, NEC, UL, and Telcordia Technologies standards as referenced in this Item. Provide test procedures and blank test forms and conduct performance tests for all materials and equipment not previously tested and approved. If technical data are not considered adequate for approval, samples may be requested for testing. The Contract period will not be extended for time lost or delays caused by testing before final approval of any items. Compare the results of each test with the requirements of this Item. Failure to conform to the requirements of any test must be identified as a defect and the materials will be subject to rejection by the Engineer. Offer rejected materials again for retest provided all non- compliances have been corrected and retested by the Contractor with evidence submitted to the Engineer.
3.5.2 Examination of Product . Examine each conduit system component before installation c arefully to verify that
the materials, design, construction, markings, and workmanship comply with the requirements of this Item.
3.5.3 References. The ITS multi -duct conduit system supplier must submit three references, preferably State
Departments of Transport ation, where the supplier's conduit system has functioned successfully for no less than 1 yr. Include current name and address of organization, and the current name and telephone number of an individual from the organization who can be contacted to verify system installation. Provide this 864 information with documentation submittal. Failure to furnish the above references will be sufficient reason for rejection of the supplier's equipment.
3.6 Documentation Requirements . Submit documentation of the conduit system consisting of the following for
the Engineer’s approval 30 days before installation: manufacturer specifications or cut sheets for all components of the conduit duct system , laboratory -certified material test reports documenting conformance with pertinent standards identified under Article 619.2, “Materials,” GPS coordinates, pre-installation test procedures, post- installation test procedures , and as-built of installed conduit system.
Article 4 — Measurement
This Item will be measured by the foot of multi -duct conduit installed . Fiber optic cable road marker will be measured by each maker furnished and installed.
Article 5 — Payment
The work performed and materials furnished in accordance with this Item and measured as provided under “Measurement” will be paid for at the unit price bid for “ITS Multi -Duct Conduit” of the types and construction method specified. This price is full compensation for furnishing and installing conduit; jacking, boring, steel encasement, excavating, furnishing, and placing backfill; concrete encasement; replacing pavement structure, sod, riprap, curbs, or other surface; testing of the conduit system ; furnishing and installing all fittings, clamps, sweeps, bends, repair couplings, adapters, ground box or manhole termination kits, pre- assembled split repair kits, lubrication access, fittings, hangers, brackets, junction boxes, expansion joints, concrete, and detectable underground metalized M ylar conduit marking tape; pull cords ; and all labor, tools, equipment , and incidentals necessary to complete the work. The work performed and materials furnished in accordance with this Item and measured as provided under “Measurement” will be paid for at the unit price bid for “Fiber Optic Cable Road Marker.” This pri ce is full compensation for furnishing and installing all cable markers, and for materials, equipment, labor, tools, documentation, warranty, training, and incidentals. Copper grounding conductor will be paid for under Item 620. This Item applies only to I TS multi -duct conduit. Any other conduit for communication or electrical use will be in accordance with and paid for under Item 618.