550Chain Link Fence

2.1 General . Furnish materials in accordance with the following.

 Item 421, “Hydraulic Cement Concrete,” Class B  Item 445, “Galvanizing”

2.2 Wire Fabric. Provide wire fabric with:

 9-gauge (0.148- in. diameter) steel wire with a minimum breaking strength of 1,290 lb. meeting ASTM A392 Class I or ASTM A491;  mesh size of 2 in. ± 1/8 in. between parallel wires with at least seven meshes in a vertical dimension of 23 in. along the diagonals of the openings; and  knuckled selvages at the top and bottom edge of the fabric, unless otherwise shown on the plans.

2.3 Posts . Provide posts of the size and weight shown on the plans. Do not provide rerolled or open- seam posts.

Use material for all posts meeting ASTM F1043 Group 1A Regular Grade or Group 1C High Strength.

2.4 Post Caps. Provide malleable iron post caps designed to exclude all moisture. Furnish barbed wire support

arms integral with the post caps if barbed wire is shown on the plans. Furnish post caps with an opening for the top rail if top rail is shown on the plans. Post caps must have a 2- in. skirt.

2.5 Gates. Provide gates fabricated from round sections of pipe of the size and weight shown on the plans. Use

material for all gate pipes meeting ASTM F1043 Group 1A Regular Grade or Group 1C High Strength. For each gate, include:  corner and tee fittings of malleable iron or pressed steel with means for attaching diagonal bracing members;  hinges of malleable iron allowing a full 180° swing, easily operated by one person;  ball-and-socket type bottom hinges that do not twist or turn from the action of the gate and prevent the closed gate from being lifted off the hinges;  a positive stop that prevents any portion of the gate from swinging over an adjacent traffic lane;  malleable iron pulley systems for roll -type gate (only when required);  diagonal braces consisting of 3/8- in. diameter cable with turnbuckles, two to each gate frame, and, for vehicle gates, a vertical pipe brace of the size and weight shown on the plans at the center of each gate leaf;  latches of malleable iron or steel for single gates with a single- fork latch and padlock eye that will keep the gate c losed;  two fork latches mounted on a center plunger rod with a padlock eye for double- leaf gates;  holdbacks for each leaf of vehicular gates, with a semi -automatic holdback catch anchored at least 12 in. into a 12- in. diameter × 24-in. deep concrete footing; and 829  a malleable iron center rest, designed to receive the plunger rod anchored as shown on the plans for all double- leaf gates.

2.6 Top Rail . Use material meeting ASTM F1043 Group 1A or Group 1C for all top rail pipes. Provide 1.660- in.

outside diameter ( OD) top rail manufactured from Group 1A standard weight (Schedule 40) steel pipe weighing 2.27 lb. per foot , or from Group 1C high- strength pipe weighing 1.84 lb. per foot when shown on the plans. Provide pipe in sections at least 18 ft. long joined with out side steel sleeve couplings at least 6 in. long with a minimum wall thickness of 0.70 in. Use couplings designed to allow for expansion of the top rail.

2.7 Tension Wire . Use 7 -gauge (0.177- in.) carbon steel wire with a minimum breaking strength of 1,950 lb. for

the bottom edge of all fence fabric, and for the top edge of fence fabric when a top rail is not specified.

2.8 Truss Bracing . Provide truss bracing as shown on the plans.

2.9 Cables. Provide seven -wire strand cables manufactured of galvanized annealed steel at least 3/8 in.

in diameter.

2.10 Barbed Wire. Provide three strands of twisted 12.5- gauge barbed wire with two-point, 14- gauge barbs

spaced approximately 5 in. apart conforming to ASTM A121 or ASTM A585 when shown on the plans.

2.11 Barbed Wire Support Arms . Provide support arms at an angle of 45° from vertical, with clips for attaching

three strands of barbed wire to each support arm and sufficient strength to support a 200- lb. weight applied at the outer strand when barbed wire is shown on the plans.

2.12 Stretcher Bars. Provide stretcher bars made of flat steel at least 3/16 × 3/4 in. and not more than 2 in.

shorter t han the fabric height. Provide one stretcher bar for each gate and end post and two stretcher bars for each corner and pull post.

2.13 Grounds . Provide copper -clad steel rods 8 ft. long with a minimum diameter of 5/8 in., or other UL- listed

ground rods.

2.14 Miscellaneous Fittings and Fasteners. Furnish enough fittings and fasteners to erect all fencing materials

in a proper manner. Furnish fittings for posts from pressed or rolled steel, forged steel, malleable iron, or wrought iron of good commercial quality spaced as shown on the plans.

2.15 Coatings . Hot -dip galvanize all materials unless specified otherwise in this Item or as shown on the plans.

Fabric, tension wire, and barbed wire may be aluminum -coated or alloy -coated if approved. Additionally , coat all material except bolts, nuts, washers, and pipe material with thermally fused polyvinyl chloride (PVC) in accordance with ASTM F668, Class 2b, meeting the specified color when shown on the plans.

2.15.1 Fabric .

2.15.1.1. Galvanizing . Hot -dip galvanize in accordance with ASTM A392, Class I. 2.15.1.2. Aluminum Coating. Aluminum -coat in accordance with ASTM A491. 2.15.1.3. Alloy Coating . Coat with zinc -5% aluminum -mischmetal alloy (Zn -5A1-MM) in accordance with ASTM F1345, Class I.

2.15.2 Posts, Braces, and Gates.

2.15.2.1. Standard Weight (Schedule 40) Pipe . Hot -dip galvanize inside and outside in accord ance with ASTM F1043 (1.8 oz. per square foot galvanized zinc weight). 830 2.15.2.2. High Strength Pipe . Hot -dip galvanize before or after forming pipe in accord ance with ASTM F1043 Group 1C and as follows .  Outside . Minimum 0.9 oz. per square foot galvanized zinc weight with a verifiable polymer overcoat.  Inside . Minimum 0.9 oz. per square foot galvanized zinc weight before forming, or minimum 0.3 mils zinc-based coating after forming containing a minimum 90% zinc dust, by weight. 2.15.2.3. Optional Additional Coating. Additionally , coat all pipe material with 10 mils minimum thermally fused PVC in accord ance with ASTM F1043, meeting the specified color when shown on the plans .

2.15.3 Fittings, Bolts, and Other Miscellaneous Hardware . Galvanize all fittings, bolts, and miscellaneous

hardware in accordance with Item 445.

2.15.4 Tension Wire . Zinc- coat tension wire with a minimum coating of 0.80 oz. per square foot, or aluminum -coat

with a minimum coating of 0.30 oz. per square f oot.

2.15.5 Barbed Wire. Zinc -coat barbed wire in accordance with ASTM A121 (0.80 oz. per square foot), or aluminum -

coat in accordance with ASTM A585 (0.30 oz. per square foot).

2.15.6 Pull Cable. Zinc- coat pull cable with a minimum coating of 0.80 oz. per square foot of individual -wire surface

when tested in accordance with ASTM A116.

3.1 Clearing and Grading. Clear all brush, rocks, and debris necessary for the installation of this fencing.

Stake the locations for corner posts and terminal posts unless otherwise shown on the plans. Follow the finished ground elevations for fencing panels between corner and terminal posts. Level off minor irregularities in the path of the fencing.

3.2 Erection of Posts . Install posts as shown on the plans. Plumb and permanently position posts with

anchorages firmly set before fabric is placed. Brace corner and pull posts as shown on the plans.

3.2.1 Post Spacing . Space posts as shown in Table 1.

Table 1 Post Spacing and Placement Post Type Required Spacing or Placement Line posts No more than 10 ft. apart Pull posts No more than 500 ft. apart and at each change in direction exceeding 20° vertically Corner posts At each horizontal angle point Install cables on all terminal posts and extend to adjacent posts. Install cables on each side of corner and pull posts using a 3/8- in. drop- forged eye- and-eye or eye- and-clevis turnbuckle unless otherwise shown on the plans. 831 3.2.2. Postholes . Drill holes for con crete footings for all posts to provide footings of the dimensions shown on the plans. Penetrate solid rock by at least 12 in. (18 in. for end, corner, gate, and pull posts) or to plan depth where the rock is encountered before reaching plan depth. Drill holes in the solid rock with a diameter at least 1 in. greater than the OD of the post. Fill the hole in the solid rock with grout consisting of one part hydraulic cement and three parts clean, well-graded sand after the posts are set and plumbed. If desired, other grouting materials may be used only if approved. Thoroughly work the grout into the hole, leaving no voids. Construct concrete footings from the solid rock to the top of the ground.

3.2.3 Gate Posts. Align the tops of all gate frames with the fencing top tension wire or top rail. Provide vehicular

gates that are greater in overall height than the adjacent fencing by the height necessary to extend to within 2 in. of the pavement between the curbs if curbs are shown on the plans.

3.2.4 Concrete Footings . Center posts in their footings. Place concrete and compact by tamping or other

approved methods. Machine mix all batches of concrete more than 1/2 cu. yd. Hand mixing concrete is allowed on batches less than 1/2 cu. yd. Use forms for footings where the ground cannot be satisfactorily excavated to neat lines. Crown the concrete or grout (for solid rock) to carry water from the post. Keep the forms in place for at least 24 hr. Backfill the footing with moistened material as soon as each form is removed, and thoroughly tamp. Cover concrete with at least 4 in. of loose moist material, free of clods and gravel, immediately after placing concrete. No other curing is required. Spread all excess excavated and loose material us ed for curing neatly and uniformly. Remove excess concrete and other construction debris from the site.

3.3 Erection of Fabric . Place the fabric with the cables drawn taut with the turnbuckles after all posts have been

permanently positioned and anchorages fir mly set . Secure one end and apply enough tension to the other end to remove all slack before making attachments. Cut the fabric , independently attach each span at all corner posts , and pull posts unless otherwise shown on the plans. Follow the finished contour of the site with the bottom edge of fabric located approximately 2 in. above the grade. Grade uneven areas so the maximum distance between the bottom of fabric and ground is 6 in. or less. Fasten fabric at 12- in. intervals to the top and bottom tension wires between posts. Fasten the fabric in the same manner when top rail is shown on the plans. Fasten the fabric on gate frames to the top and bottom of the frame at 12- in. intervals. Use steel wire fabric ties of 9- gauge steel or larger. Fasten fabric t o terminal posts using steel stretcher bars and stretcher bar bands fitted with carriage bolts and nuts of the size and spacing shown on the plans. Use stretcher bars to fasten end posts, pull posts, corner posts, and gateposts with stretcher bar bands at intervals of no more than 15 in. Attach stretcher bars to terminal posts using 1 × 1/8-in. flat steel bands with 3/8- in. carriage bolts at intervals up to 15 in.

3.4 Electrical Grounds. Provide at least one electrical ground for each 1,000 ft. of fence, locate d near the

center of the run. Provide additional grounds directly under the point where power lines pass over the fence. For fence placed on bridge structures, install grounds as shown on the plans. Vertically drive or drill in the grounding rod until the top of the rod is approximately 6 in. below the top of the ground. Connect a No. 6 solid copper conductor to the rod and to the fence by a UL- listed method so that each element of the fence is grounded.

3.5 Repair of Coatings . Repair damaged zinc coating in ac cordance with Section 445.3. 4., “Repairs.”

832 4. MEASUREMENT Chain link fence will be measured by the foot of fence installed, repaired, replaced, or removed, measured at the bottom of the fabric along the centerline of the fence from center to center of posts, excluding gates. Gates will be measured as each gate installed, repaired, replaced, or removed.

5.1 Chain Link Fence (Install) . This price is full compensation for furnishing and installing fencing, except gates;

cleaning, grading, and backfilling; removing and disposing of surplus material; and equipment, labor, tools, and incidentals.

5.2 Chain Link Fence (Repair) . This price is full compensation for furnishing materials; repairing or replacing

fencing, except gates; cleaning, grading, and backfilling; removing and disposing of surplus or damaged material; and equipment, labor, tools, and incidentals.

5.3 Chain Link Fence (Remove). This price is full compensation for removing all fencing, except gates; cleaning, grading, and backfilling; removing and disposing of surplus material; and equipment, labor, tools, and incidentals.

5.4 Gate (Install) . This price is full compensation for installing gate and for providing materials, center

anchorages, equipment, labor, tools, and incidentals.

5.5 Gate (Repair) . This price is full compensation for repairing or replacing gate and for furnishing materials;

removing and disposing of damaged materials; and equipment, labor, tools, and incidentals.

5.6 Gate (Remove) . This price is full compensation for removing gate and for materials, equipment, labor, tools,

and incidentals.