705.01 Guardrail
Furnish steel beam and cable guardrail materials in accordance with the contract. Manufacturers of steel beam guardrail must be listed on the QPL.
705.01.1 Steel Beams and Fittings
Furnish steel beam guardrail in accordance with AASHTO M 180, Class A, Type 1 requirements. Supply rail in lengths that place the splices on posts. Shape rail to be erected on curve radii less than 150 feet (45.75 m) before erecting. Use ASTM A307 bolts with ASTM A563, Grade A or better nuts. Use ANSI B27.2, Type A plain steel washers. Galvanize all bolts, nuts, washers, and fittings in accordance with ASTM A153 or B695 (Class 50). Furnish rounded end sections, buffer sections, and terminal connectors in accordance with AASHTO M 180, Class B, Type 1.
705.01.2 Wood Posts and Blockouts
Furnish wood posts and blockouts made from Douglas fir, Hemlock, Ponderosa Pine, Spruce, Larch, Southern Yellow Pine, or Lodgepole pine. Furnish posts that are straight, sound, free from defects, and meet the dimensions specified in the contract. Meet the Western Wood Products Association requirements or equivalent grading rules for No. 2 grading or better in accordance with ASTM D245. Ensure the posts surfaces do not vary more than 1-inch (25 mm) from a straight line connecting the ends. Saw the wood posts before treating. Ensure the wood posts and blockouts are seasoned to accept the specified treatment in accordance with Subsection 705.03.1 . Other acceptable blockouts may be manufactured from recycled plastic or recycled plastic with wood fibers provided they meet the requirements of Subsection 606.03.1. Use only one type of blockout in each run of guardrail.
705.01.3 Concrete Posts
Furnish precast concrete posts in accordance with the contract. Use Class General concrete or concrete of equal strength in accordance with Section 551. Manufacture, transport, and handle guardrail posts in accordance with Section 554. Use reinforcing steel in accordance with Section 711.
705.01.4 Lightweight Concrete Guardrail Posts
Lightweight aggregates may be used in manufacturing guardrail posts. Produce both fine and coarse aggregates for lightweight concrete by expanding, calcining, or sintering blast furnace slag, clay, diatomite, shale, or slate. Meet AASHTO M 195 aggregate requirements. Use separate fine and coarse aggregate. Use fine aggregate in the No. 4 (4.75 mm) to 0 size. Use coarse aggregate of either ¾-inch (19.0 mm) to No. 4 (4.75 mm) or ½-inch (12.5 mm) to No. 4 (4.75 mm). Meet a minimum compressive strength of 3,000 psi (20.7 MPa) (equal to Class General concrete) with a maximum absorption of 15% by volume and a maximum unit weight of 115 pounds per cubic foot (1,864 kg/m 3). Aggregate pre-wetting may be required. 705 – GUARDRAIL 2020 EDITION V5.1 705-2 Use reinforcing steel in accordance with Section 711. Steel size and shape is specified in the contract. The AASHTO M 195 Freeze-Thaw test is not required.
705.01.5 Steel Posts
Furnish steel posts for cable guardrail in accordance with the contract. Spot paint all bruised, broken, scaled, or damaged coating on steel posts with two coats of cold galvanizing compound following the paint manufacturer’s recommendations. Furnish minimum 6-foot (1830 mm) long steel guardrail posts for steel beam guardrail. Ensure that steel guardrail posts and associated hardware meets the AASHTO Guide to Standardized Highway Barrier Hardware (Task Force 13 Report).
705.02 Wire Rope and Connecting Hardware
Furnish wire rope and hardware for cable guardrail in accordance with the contract.
705.03 Wood Treatment and Painting
705.03.1 Wood Treatment
Furnish wood posts and blocks pressure treated in accordance with Subsection 706.04.1 using commodity specification A with retention specifications from commodity specification B, use category 4B. Chamfer and perform other required framing and boring of bolt holes before post treating. Plug drill holes used for determining preservative penetration depth with tight fitting treated wood plugs.
705.03.2 Painting
Use paint and perform painting in accordance with the contract.
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