456 SECTION 862
862.01 General
Provide steel components of guardrail galvanized according to Section 854, “Galvanizing ”.
862.02 Wire Rope and Fittings for Cable Guardrail
A.Wire Rope and Connecting Hardware. Provide wire rope and connecting hardware that meet AASHTO M 30, Type I, Class A. Provide connecting hardware that develops the full strength of a single cable 25,000 pounds.
B.Cast Steel Components. Provide cast steel components that meet AASHTO M 103.
C.Socket Baskets and Wedges. Design socket baskets for use with the wedge detailed on the plans.
D.Bolts, Nuts, and Washers. Use bolts that meet ASTM A 307, Grade A. Use nuts that meet ASTM A 563, Grade A. Use hook bolts that, when installed, develop an ultimate pull open strength between 500 and 1,000 pounds applied in a direction normal to the longitudinal axis of the post. Use steel washers that meet the dimensional requirements of ANSI B 27.2, Type A plain washer.
E.Washer Plates. Use end and line post washer plates that meet AASHTO M 183.
862.03 Guardrail Units and Fittings for W- Beam Guardrail
Provide W-Beam guardrail units, backup plates, flared end sections, and buffer end sections that meet AASHTO M 180, Class A, Type II. Use terminal connectors that meet AASHTO M 180, Class B, Type II.
A.Button Headed Bolts and Hex Bolts. Use button headed bolts that meet ASTM A 307. Use hex bolts that meet ASTM A 307, Grade A. Use nuts that meet ASTM A 563, Grade A.
B.Plates. Use rectangular plate washers that meet AASHTO M 180. Use break -away cable treatment, cable end plates, bearing plates, and anchor plates that meet AASHTO M 180. 457 C. Washers. Use steel washers that meet the dimensional requirements of ANSI B 27.2, Type A plain washers.
D.Break -Away Cable Terminal Assembly. Use a stud that meets ASTM A 449. Ensure threads are ANSI Class 2A fit before galvanizing. Before galvanizing, mill a 3/8-inch slot into the stud end for the locking pins. Use a swaged fitting machined from hot-rolled carbon steel that - Meets ASTM A 576, Grade 1035; - Is annealed suitable for cold swaging; and - Was galvanized before swaging. Drill a lock pin hole to accommodate a 1/4 inch plated spring steel pin through the head of the swage fitting to retain the stud in the proper position. After galvanization, the Engineer will allow the head to be tapped 0.023 inch over ANSI Class 2B Tolerance. Use wire rope that meets AASHTO M 30, Type II, Class A. Use the swaged fitting, stud, and nut to develop the breaking strength of the wire rope. Use steel washers that meet the dimensional requirements of ANSI B 27.2, Type A plain washers. Use a one inch nut that meets ASTM A 563, Grade A. After galvanizing, the Engineer will allow the pitch diameter of the nut to be tapped 0.023 inch over the ANSI Class 2B Tolerance.
E.W-Beam Guardrail End Treatments. Provide W-beam guardrail end treatments that meet the requirements of MASH TL -3. Provide an impact head that is capable of flattening, cutting, kinking or bending the guardrail away from the impacting vehicle. Attach the impact head to the first post as specified by the supplier. Anchor a breakaway cable assembly to the guardrail. Use break away posts and standard line posts for the remaining posts. Provide guardrail elements that are 12 gauge sections meeting AASHTO M 180. Provide timber posts that meet requirements for materials that passed the crash testing.
862.04 Treated Wood Guardrail Posts
A.General. Provide timber used for treated wood posts for beam guardrail that is made from timber with a stress grade of 1,200 psi or more. Test according to West Coast Lumber Inspection Bureau, Southern Pine Inspection Bureau, or other appropriate timber association. Provide posts meeting the following: - No decay; - No knots that are unsound, not smoothly -trimmed, and do not impair the post’s strength; 458 - No checks wider than 1/4 inch or deeper than 3 inches; - One way sweep that does not exceed 1-1/2 inches; - No exaggerated and unsightly winding twist; - No short kinks; and - No defects that give the post an unsightly appearance. Before treatment, shave off all the inner bark and closely trim the knots of round timber posts. Use a preservative that meets Section 846, “Preservatives and Pressure Treatment Processes for Timber” . Use the same treatment for all posts on the Project. Treat timber offset blocks.
B.W-Beam. Provide rectangular timber posts and offset blocks that are either rough sawn or S4S with nominal dimensions shown in the Contract. After end cuts have been made and holes have been drilled, treat posts and offset blocks as specified in Section 846.01, “Timber Preservatives” . Use a size tolerance for rough sawn blocks of 1/4 inch in the directions of the bolt holes. Use rough sawn blocks that meet the same requirements as the treated timber guardrail posts.
C.3-Cable. Provide round treated timber posts used for three-cable guardrail that are between 4.5 and 6.5 inches in diameter .
862.05 Steel Guardrail Post
Provide steel posts, adjustment blocks, blockouts, attachment angles, and base plates that meet AASHTO 270 Grade 36. Section 880 459 SECTION 880 PAVEMENT MARKINGS
880.01 Water Based Pavement Marking Paint
A.Material Requirements.
1.General. Use acrylic emulsion polymer or modified acrylic polymer in the manufacture of the water - based pavement marking paint. Provide paint capable of receiving and holding glass beads for producing retroreflective pavement marking. Provide paint that is free of heavy metals as defined by the EPA. Provide finished paint that is: • Fast-drying; • Capable of withstanding air and roa dway temperatures without: o Bleeding; o Staining; o Discoloring; or o Deforming; • Smooth; • Free of: o Coarse particles; o Skins; or o Any other deleterious materials that are detrimental to its use or appearance; • Homogeneous; and • Will not have detrimental interactions with common roadway chemicals. Provide paint film that is capable of maintaining the original dimensions and placement during the curing period without: • Chipping; • Spalling; or • Cracking.
2.Physical Properties
a.General Provide paint with the physical properties specified in Table 880-01.
Source: North Dakota Standard Specifications for Road and Bridge Construction, 2022 Edition. Pages 491–493 of 550.