719.03 Signs
720 SECTION 719
719.01 Panels
A.Aluminum
1.Sheet Aluminum Provide sheet alum inum signs in accordance with ASTM B 209, alloy 6061 -T6 or alloy 5052 -H38 with mill finish. Use the dimensions, hole sizes, and hole locations shown on the Plans. Ensure panels are flat and straight within commercial tolerances. Treat sheet aluminum sig ns with a chromate type chemical conversion coating in accordance with ASTM B 449, Class II.
2.Extruded Aluminum Provide extruded aluminum panel signs in accordance with ASTM B 221, alloy 6063 -T6 with the dimensions, hole sizes, and hole locations shown on the Plans. Keep panels flat and straight within commercial tolerances. Ensure extruded aluminum is free of corrosion, white rust, and dirt. Provide aluminum edge strip in accordance with ASTM B 221, alloy 6063 -T6. Place aluminum sheet metal screws wi th slotted pan heads on centers no greater than 24 in [609.6 mm] to secure the edge strips to the sign panels. On signs less than 36 in [914.4 mm] wide, use at least three screws.
B.Sign Faces Make sign faces in accordance with the drawings in the latest revision of the MUTCD , and as shown on the Plans.
719.02 Support Arms and Fit Tings
A.Materials Use structural steel for sign supports of sheet signs in accordance with AASHTO M 270 (ASTM A709), Grade 36, or aluminum alloy in accordance with ASTM B 221, alloy 6063 -T6.
B.Fabrication Provide pre -fabricated sign supports, bracket arms, and fittings that are cut to the shapes and dimensions shown on the Plans before degreasing, etching, and applying reflective sheeting. Ensure parts are free of buckles, warp, dents, cockles, burrs, and defects.
719.03 Sheet and Extruded A Luminum Sign Fastene Rs
Use aluminum fasteners and collars sized as indicated on the plans for fastening sheet aluminum signs to si gn bracket arms. SIGNS 719.05 721 Use aluminum ASTM B 209, alloy 2024 -T4 for panel bolts, hex nuts, post clip bolts, stop nuts, and flat washers. Attach extruded aluminum signs to posts on each side with post clips, post clip bolts, and nuts and flat washers, as shown on the Plans. Use flat washers under nuts to prevent gouging.
719.04 Retroreflective Shee Ting
A.Description Use retroreflective sheeting to make reflectorized sign faces as shown on the Plans. Provide Type III retroreflective sheeting, unless otherwise re quired by the Contract.
B.Requirements Provide materials for retroreflective sheeting in accordance with ASTM D 4956, and the supplementary specifications of S3. Provide sheeting with a Class 1 adhesive backing. Perform outdoor weathering on an AASHTO, National Transportation Product Evaluation Program test deck. The Resident Engineer will inspect completed signs, and will not accept sign faces with faults or blemishes that impair serviceability or mismatched colors visible from a distance of 25 ft [7.6 m] under day or night light conditions.
719.05 Sign Copy (Screen Co Py)
A.Direct Screening Process The Department will allow the direct screening process for applying a non -reflectorized copy on reflectorized or non -reflectorized backgrounds. This process normally applies to black copy.
B.Reverse Screening Process Use the reverse screening process to provide reflectorized messages on colored backgrounds with transparent color stencil paste applied to a silver white sheeting background. This process norma lly applies to white copy, for example, the “STOP” sign.
C.Material and Application Apply a top quality exterior baking screen enamel or stencil pa ste for the silk screen method that is designed for roadway signs and compatible with the type of background material. Apply and cure the screened copy in accordance with the manufacturer’s recommendations for the background material. Use durable colors in accordance with the FHWA Standards Colors Charts for Signs. Ensure the colors appear uniform in hue when viewed in daylight and under normal headlights at night.
D.Final Finish Treat signs after completion in accordance with Subsection 850.04.C, “Finishing Signs.”
E.Tests Ensure screening enamel, stencil pastes, and process inks do not discolor, crack, craze, blister, or lift when applied and exposed to accelerated weathering for 1,000 hr in accordance with Federal Test Method 141/6151.
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.” SECTION 720 OVERHEAD ALUMINUM TRUSS SIGN STRUCTURES
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.
Source: Oklahoma Standard Specifications for Highway Construction, 2019 Edition. Pages 734–735 of 935.