DelDOT Standard Specifications 846: Loop Detector

846.1Description.

This work consists of providing and placing loop detectors.

846.2Materials.

B.Backer Rod, Closed Cell Section 1043

C.Conduit, Galvanized Section 1062

D.Loop Detector Section 1079

E.Tape Section 1074.2.F

F.Heat Shrink Tubing Section 1074.2.G.1

G.Loop Wire Section 1079.1

H.Home Run Cable Section 1074.1.D

I.Backer Rod – 5/8-inch closed cell foam. Section 1043

J.Junction Well Splices Section 1074.2.G

K.Splicing Kit Section 1074.2.G.3

L.PCC Patching Section 1023

M.Asphalt Production Section 1014

N.Joint Sealant Section 1042.1.B

846.3Construction.

846.3.1 Loop Wire Installation.

A.Sawcut a groove in the pavement 5/8-inch wide and at least 3 1/2-inches deep in accordance with

Section 762. Remove sharp edges in the saw cut and round the corners. Blow out the saw cut with compressed air to remove loose material before sealing.

B.Install the loop detector wire using blunt tools to prevent damage to the polyethylene outer

cover.

C.Tag 1 end of a loop detector wire to indicate start with an “S.”

D.Place a 5/8-inch backer rod on top of the wire in the saw cut as needed to secure the wire within

the saw cut.

E.The engineer may require a high voltage ground test with a 500 volts DC megger after completion

of the loop detector installation and before sealing saw cuts. If the resistance to ground is less than 100 megaohms, remedy the work.

F.Apply a sealer, and sealer accelerant or retarder, if necessary, in the saw cut, in accordance with

the manufacturer’s directions. Protect the saw cut area from traffic until the sealer has set. Place a minimum of 1 inch of sealer on top of the loop detector wire and finish flush with the pavement. Seal any drilled holes in the pavement.

G.Install 2 loop detector wires in a saw cut from the loop to the edge of the road. Extend these 2

wires from the end of the saw cut to a junction well. Twist the wires a minimum of 5 wraps per

foot in a parallel direction, and tape every 12-inches to 18-inches from the end of the saw cut to a junction well up to the splice.

H.Where the junction well is directly behind the edge-of-pavement, curb or sidewalk, bore a 1 1/2-

inch rotary drill hole between the edge-of-pavement, curb, or sidewalk and the junction well, in accordance with the contract. Install loop detector lead-in wire through the rotary drill hole into the junction well and splice accordingly.

I.When the junction well is not directly behind the edge-of-pavement, curb or sidewalk, install a

length of 1 1/2-inch galvanized rigid metal conduit and weatherproof fitting between the rotary drill hole and junction well, in accordance with the contract. Install the loop detector lead-in wire through the rotary drill hole, 1 1/2-inch conduit, and junction well and splice accordingly.

J.Install the loop detector wire in a continuous manner and without splices from the junction well

through the saw cuts and through the conduit. 846.3.2 Home-run Wire Installation.

A.Refer to Sections 831 and 832 for cable installation and conduit installation specifications. Refer to

the contract for details. 846.3.3 Splicing.

A.Complete splices between the loop detector wire and home-run cable in accordance with the

contract. Solder conductors side-by-side, with the exposed copper aligned. Twist the copper clockwise to achieve a mechanical connection. Coat the splice with flux, heat with a soldering iron, and solder with a rosin core solder. Insulate each soldered connection with heat-shrink tubing.

B.Test all circuits after completing the electrical and mechanical connections and before installing the

splicing kit. Install an approved splice kit in accordance with the manufacturer’s instructions. The Department will perform a continuity test at the cabinet after application of the splicing kit.

C.Remake the splice if the splice becomes faulty within 90 calendar days after splicing. The

Department’s ITS technician will make the determination if the splice is watertight or not or if wires are crossed or mislabeled.

D.Provide an overlap of the conductor insulation of at least 1 1/2-inches at each end of the heat-

shrink tube or the open end of the end cap of heat-shrink tubing after contraction.

846.4Method of Measurement.

The Department will measure the quantity of loop detector wire or conduit as the number of linear feet of saw cut where loop detector wire is placed, sealed, and accepted. The Department will include the length of loop wire installed between the saw cut and the junction well in this measurement.

846.5Basis of Payment.

A.The Department will pay the quantity of loop detector wire provided, placed, sealed, and

accepted at the contract unit price. Price and payment constitutes full compensation for:

1.Sawcutting and

2.providing and placing:

a.loop detector wire,

b.backer rod,

c.sealer, and

d.sealer accelerant or retarder.

3.junction well splicing.

B.The Department will pay the quantity of 1 1/2-inch galvanized rigid metal conduit detector sleeve

with loop wire provided, placed, and accepted at the contract unit price. Price and payment constitutes full compensation for:

1.Providing and placing galvanized rigid metal conduit;

2.loop wire;

3.drilling required for installation;

4.concrete or pavement patching;

5.sealing the conduit ends; and

6.internal bushings.

ITEM DESCRIPTION UNIT 846001 PROVIDE AND INSTALL LOOP WIRE 1-CONDUCTOR #14 AWG ENCASED IN 1/4” FLEXIBLE TUBING IN A LOOP SAWCUT LF 846002 PROVIDE AND INSTALL A 1 1/2-INCH GALVANIZED RIGID METAL CONDUIT DETECTOR SLEEVE WITH LOOP WIRE LF

Referenced in this section

LOOP DETECTOR in other states

Arkansas 704 · LOOP DETECTOR

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Source: Delaware Standard Specifications for Road and Bridge Construction, 2026 Edition. Pages 540–0 of 786. View official source ↗

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846LOOP DETECTOR

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