720.01 Overhead Aluminum Truss Sign Structures
722 719.06 RETROREFLECTIVE AND NON -RETROREFLECTIVE CUTOUT LETTERS, NUME RALS, ARROWS, S YMBOLS, AND BORDERS Design letters in accordance with the 1966 FHWA standard alphabets (as revised). For retroreflective cutout letters, use Type III or Type IV retroreflective sheeting in accordance with Subsection 719.04, “Retroreflective Sheeting.”
720.01 Aluminum
A.Aluminum Alloy Extruded Tube Provide aluminum alloy extruded tube, in accordance with ASTM B 221, all oy 6061 T6.
B.Aluminum Alloy Permanent Mold Castings Provide aluminum alloy permanent mold castings in accordance with ASTM B108/B108M, alloy SC 70A, F or T 71.
C.Aluminum Alloy Sand Castings Provide aluminum alloy sand castings in accordance with ASTM B26/ B26M, alloy SC 70A, F or T7.
D.Aluminum Alloy Plate Provide aluminum alloy plate, in accordance with ASTM B 209, alloy 6061 T6.
E.Aluminum Alloy Bolts Provide aluminum alloy bolts consisting of rod, in accordance with ASTM B 211, alloy 2024 T4. Prov ide bolt heads in accordance with American Standard Regular Hexagon, ASA B18.2. Ensure the threads are in accordance with Class 2 or Class 2A. Give the finished bolt an anodic coating in accordance with a No. 204 aluminite finish. As an alternative, the Department will allow the use of stainless steel bolts in accordance with ASTM F 593.
F.Nuts Provide self -locking nuts in accordance with the Air Force -Navy Aeronautical “Nuts, Self -Locking, AN-N-5b,” or an equivalent approved by the Resident Engineer. As an alternative, the Department will allow the use of stainless steel nuts in accordance with ASTM F 594.
G.Aluminum Alloy Washers Provide aluminum alloy washers, made from sheet aluminum in accordance with ASTM B 209, alloy 2024 T4. OVERHEAD ALUMINUM TRUSS SIGN STRUCTURES 720.03 723 As an alternative, th e Department will allow stainless steel washers in accordance with ASTM F 594.
H.Aluminum and Aluminum Alloy Welding Rods and Bare Electrodes Provide filler wire for welding in accordance with AWS A5.10.
I.Aluminum Extruded Shapes Provide aluminum extruded structural shapes, in accordance with ASTM B 221, alloy 6061 T6.
J.Aluminum Alloy Pipe Provide aluminum alloy pipe for handrail in accordance with ASTM B241/B241M, schedule 40, alloy 6063 T6.
K.Anchor Bolts, Nuts, and Washers Provide anchor bolt s, nuts, and washers in accordance with ASTM A 307 for steel machine bolts, nuts, and tap bolts. Ensure the exposed portion plus 6 in [152 mm] of steel anchor bolts, nuts, and washers are zinc -plated. As an alternative, the Department will allow stainless steel bolts, nuts, and washers in accordance with ASTM F 593 and ASTM F 594.
720.02 Steel
A.Tube or Pipe Members Provide round tube or pipe members in accordance with ASTM A53/A53M, Grade B. Galvanize both horizontal truss units and the vertical end sup port units in accordance with AASHTO M 111, after welding, and punching or drilling holes.
B.Bolts, Nuts, and Plain Washers Provide bolts, nuts, and plain washers of the size required by the Contract in accordance ASTM F3125. Galvanize bolts, nuts, and p lain washers in accordance with AASHTO M 232 (ASTM A153).
720.03 Welding Requirement
A.Welding Requirements for Aluminum Provide welding aluminum alloys for sign structures, bridge rails, and lampposts. Interpret welding terms in accordance with the defi nitions in AWS Definitions -Welding and Cutting (AWS A3.0). The welding symbols indicated on the plans are shown in the Standard Welding Symbols (AWS A2.1). Explain special conditions in added notes or details. Weld in accordance with ANSI/AWS D1.2.
1.Qualification of Procedures, Welders, and Welding Operators Ensure joint welding procedures, welders, and welding operators are qualified by tests in accordance with ANSI/AWS D1.2 Aluminum Structural Welding Code before beginning welding
720.04 Overhead Aluminum Truss Sign Structures
724 operations. The Res ident Engineer may accept evidence of previous qualification of the joint welding procedures, welders, and welding operators. Use the same process and equipment required by the Contract for the work to qualify welders and welding operators.
2.Identifica tion Marks
a.Fabricators Identification Mark Use low -stress stencils to make identification marks. Ensure the Fabricator’s mark is adjacent to the item number on each structure.
b.Welders Identification Marks Use low -stress steel dyes to make identifi cation marks. Ensure the figures on the dyes are at least ½ in [12.5 mm] high. Place the marks adjacent to primary member welds. Highlight the marks to facilitate inspection.
3.Weld Quality Ensure welds are in accordance with ANSI/AWS D1.2. To avoid rejection of an entire piece or member that contains unacceptable welding, correct defective welds in accordance with ANSI/AWS D1.2. Repair defective welds if approved by the Resident Engineer, at no additional cost to the Department.
4.Inspection To de termine compliance for weld quality, the Resident Engineer will visually inspect welds. The Resident Engineer will also inspect welds subjected to computed stress by the dye penetrant method, except for the following: For highway sign structures, use the dye penetrant method on fillet welds that connect columns to bases and main chord members, including the associated flanges, gussets, or main load -carrying brackets or members, as well as on fillet welds connecting flanges to the main truss chord members. The Resident Engineer will perform dye penetrant tests in accordance with ASTM E 165/E165M , Method B, Procedure B-2 or Procedure B-3. The Resident Engineer may omit the dye penetrant inspection if the inspector uses a 3X magnifier to examine each layer of weld metal before the next layer is deposited.
B.Welding Requirements for Steel Ensure welding material and methods, including welder qualification, are in accordance with ANSI/AWS D1.1.
720.04 Fabrication
Submit to the Resident Engineer a Type A certifi cation in accordance with Subsection 106.04, “Material Certifications,” that covers each component part of the structure before fabrication. Ensure the structure has no sharp edges, irregularities, misfits, or structural deficiencies. Ensure each member fits and can be quickly erected. Before shipment, the Resident Engineer will inspect the completed structure at the fabrication site. GALVANIZED STEEL SIGN POSTS 721.03 725 720.05 SHIPPING AND ERECTIO N Protect the structures to prevent damage or defacement during transportation or handling. Th e Resident Engineer will visually inspect the structure when delivered to the project. Repair or replace defects as approved by the Resident Engineer, at no additional cost to the Department . The Department will not allow the use of metal tie -downs in di rect contact with the structure. The Resident Engineer will not accept damaged or defaced galvanized steel structures, unless in the opinion of the Resident Engineer, the injury or defacement is so slight that it can be quickly and efficiently re-galvanize d or metalized in accordance with AWS C2.2.
720.06 Electrical Requireme Nts
Provide electrical equipment, materials, and installation methods in accordance with NEC and the electrical code in the appropriate jurisdiction. If power is not present at the project site, provide temporary power to the site to demonstrate proper installation of fixtures and equipment. SECTION 721 GALVANIZED STEEL SIGN POSTS
721.01 Pipe Posts
Provide posts made of new galvani zed steel pipe in accordance with ASTM A 53/ A 53M or ASTM F 1083. Use standard weight, Schedule 40 pipe. Provide cap plates made of, ASTM A709, Grade 36 structural steel, galvanized in accordance with AASHTO M 111. Galvanize pipe posts after fabricatio n, hole punching, or drilling, except, for signs that are minor items or incidental construction, drill or punch sign post holes and cut one end to length after galvanizing as approved by the Resident Engineer. Treat the exposed metal surfaces of these mi nor items or incidental construction by re -galvanizing, metalizing, or painting with at least 90 percent zinc -rich paint.
721.02 Wide Flange Beam Pos Ts
Provide galvanized steel wide flanged beams in accordance with ASTM A709, Grade 36. Galvanize in accord ance with AASHTO M 111 after cutting, punching, or drilling holes.
721.03 Square Tube Posts
Provide square tube posts made from new hot -rolled carbon sheet steel, structural quality, ASTM A 1011/ A 1011M. Provide a finish that is in -line, hot -dip galvanized zinc coating in accordance with AASHTO M 111, followed by a chromate conversion coating, and a clear organic exterior coating. Provide posts with 7/16 in [11.1 mm] diameter holes or perforated holes spaced 1 in [25.4 mm] on center along the center of each of the four sides.
Source: Oklahoma Standard Specifications for Highway Construction, 2019 Edition. Pages 736–738 of 935.