351 SECTION 750 DETECTABLE WARNING PANELS, SIDEWALKS, DRIVEWAYS, AND MEDIANS
750.01 Description
This work consists of constructing detectable warning panels, sidewalks, driveways, and medians.
750.02 Equipment
Equipment Section Concrete Equipment 155
750.03 Materials
Item Section Concrete Class AE 802 Impervious Membrane Cure 810.01 B Preformed Expansion Joint Material for Structural Construction 826.02 C or F Reinforcing Steel, Dowel Bars, and Tie Bars 836 Detectable Warning Panels 885 For imprinted concrete use any size coarse aggregate specified in Section 802.01 C.2, “Coarse Aggregate” . Produce a mix that consists of 60 percent fine aggregate and 40 percent coarse aggregate.
750.04 Construction Requirements
A.Forms. Use fixed forms or slip forms. If using fixed forms, construct straight forms so that the top face and the contact surface do not vary from true by more than 1/4 inch when measured using a 10 foot straightedge. On curves, install forms to within 1/2 inch of the specified radius.
B.Excavation. Eliminate deviations greater than 1/2 inch when measured with a 10 foot straightedge. Compact the subgrade as specified in Section 203.04 G .4, “Compaction Control, Type C” . Remove all soft and yielding materials and replace the volume with aggregate base.
C.Mixing Pigmented Concrete. While the mixer is operating at mixing speed, add pigment to the concrete at a ratio recommended by the manufacturer. Uniformly blend the pigment into the concrete.
D.Placing Concrete. Place concrete on a damp surface. Uniformly consolidate concrete by vibration. Repair or replace concrete if honeycombed areas are exposed when the forms are removed. The Engineer will determine if replacement is required. When repairing honeycombed areas, 352 use mortar composed of one part cement and two parts sand, mixed with water to proper consistency.
E.Finishing. Do not use water to facilitate finishing. Finish the exposed surfaces with a wood float. Roughen the surface by passing a stiff bristled broom transversely across the surface. To finish imprinted concrete, initially us e a wood float, and then place a sheet of plastic over the concrete before imprinting. Imprint the concrete with the specified pattern to a depth between 1/2 inch and 3/4 inch. Finish edges with a 1/4 inch radius edging tool.
F.Joints.
1.General. Place 3/4 inch isolation joints at 150 foot maximum spacing and between the sidewalk and any abutting curb, pavement, driveway, or other structure. Use a 1/4 inch radius edging tool on isolation joints. Saw or use a 1/4 inch radius edging tool on all other joints. Saw joints in a timely manner to prevent uncontrolled cracking.
2.Medians. When placing joints in median concrete, place 3/4 inch isolation joints at 150 foot intervals. Saw contraction joints.
G.Curing. Apply the final cure within 30 minutes of placing the concrete. Cover the entire concrete surface wi th an impervious membrane cure. Immediately cover the exposed sides of the concrete pavement with curing compound if removing forms exposes curing concrete before the expiration of the curing period. If weather conditions cause rapid drying of the concrete surface, apply a fine mist or fog spray to the concrete surface for interim curing. Do not apply water with brushes. For curing pigmented concrete, use a clear, all resin based curing compound. If the ambient temperature falls below 40°F, maintain the concrete surface temperature between 40°F and 90°F for the duration of the curing period. If Class ASE concrete is used, maintain the surface temperature between 50°F and 90°F. Conduct heating operations to avoid sudden temperature changes in the concrete. Before removing any enclosures, decrease the concrete’s surface temperature to the air temperature at a rate not to exceed 15°F per hour. The Engineer will suspend the paving operations if the cure is not properly applied. 353 Maintain the surface temperature of newly placed concrete above 40°F for 5 days. Submit a detailed temperature maintenance plan before placing concrete, if the ambient temperature is expected to drop below 40°F.
H.Detectable Warning Panels.
1.General. Install the panels by wet setting in concrete according to the manufacturer’s recommendations.
2.Dome Alignment. Align the rows of truncated domes in a detectable warning surface perpendicular to the grade break of the curb ramp.
3.Rail Crossings. Place the detectable warning surface so that the edge nearest the rail crossing is 6 feet minimum and 15 feet maximum from the centerline of the nearest rail. Align the rows of the truncated domes in the detectable warning surface with the direction of travel.
750.05 Method of Measurement
The Engineer will measure as specified in Section 109.01, “Measurement of Quantities”.
750.06 Basis of Payment
Pay Item Pay Unit Sidewalk Concrete Square Yard Imprinted Concrete Square Yard Pigmented Concrete Square Yard Pigmented Imprinted Concrete Square Yard Driveway Concrete Square Yard Detectable Warning Panel Square Foot Such payment is full compensation for furnishing all materials, equipment, labor, and incidentals to complete the work as specified. Section 752 354 SECTION 752 FENCING
752.01 Description
This work consists of constructing fences, removal of fences, and resetting fences.
752.02 Equipment
Reserved.
752.03 Materials
Item Section Concrete Class AE 802 Grouts and Epoxy 806 Fence 860 Chain Link Fence 860.01 Barbed Wire Fence 860.02 A Woven Wire Fence 860.02 B
752.04 Construction Requirements
A.Installing Line Posts.
1.General. Place all posts as close to the plan specified intervals as conditions allow. At sharp changes in grade, install extra posts to maintain the wire or chain link the proper distance from the ground. Align and plumb all posts. Where the slope of the terrain makes it impractical to set the posts plumb, set the posts as directed by the Engineer. Drive posts for barbed wire fence and woven wire fence, or set the posts in holes. If rock is encountered and the Engineer determines the post cannot be relocated, dr ill holes a minimum depth of 12 inches into the rock or to the required embedment depth of the post, whichever is less. Cut the post to provide the required height above the ground. Grout the post into the rock.
2.Driven posts. If soil conditions prevent proper driving of posts, drill a pilot hole no larger than the diameter of the post minus one inch.
3.Set posts. When posts are set in holes, drill the holes large enough to allow proper tamping. Set wood posts with the large end down. Place and compact the backfill in lifts not exceeding 6 inches of compacted material. Use all the excavated earth and slightly crown the backfill.
Source: North Dakota Standard Specifications for Road and Bridge Construction, 2022 Edition. Pages 386–388 of 550.