916.01 982 SECTION 916 – HIGHWAY SIGNING MATERIALS
916.01 General Requirements ................................ ................................ .. 982
916.02 Aluminum and Composite Material Signs ................................ ... 982
916.03 Steel ................................ ................................ .............................. 983
916.04 Stainless Steel ................................ ................................ .............. 984
916.05 Fabrication ................................ ................................ ................... 984
916.06 Reflective Sheeting ................................ ................................ ...... 988
916.07 Legends, Borders, and Accessories ................................ .............. 988
916.08 Flexible Delineator Posts ................................ ............................. 989
916.01 General Requirements
In constructing highway signs, use all new parts that conform to the requirements of these Specifications, the Plans, and the AASHTO Standard Specifications for Structural Supports for Highway Signs, Luminaires, and Traffic Signals, latest edition. To request any departures from the materials and fabrication shown on the Plans or specified in the Specifications, submit details of such departures, and the reasons they are necessary, to the Engineer for approval. Do not make any such departures without the Engineer’s prior written approval. Furnish the Department notarized certified copies of the chemical and physical properties o f all materials incorporated in the structures and accessories that are required for this work.
916.02 Aluminum and Composite Material Signs
Provide aluminum and composite materials conforming to the requirements in Table 916.02 -1, unless otherwise specified. 916.03 983 Table 916.02 -1: Aluminum and Composite Sign Components Item ASTM Specification Alloy and Temper Flat sign sheets (sign blanks) and plates (permanent and temporary) (1) B209 6061-T6 or 5052-H38 Extruded shapes (sign panels), bars, rods B221 6063-T6 Posts and truss chords B221 6061-T6 Structural shapes B308 6061-T6 Delineator sheets B209 6061-T6 Post and truss bracing members B221 6063-T6 Bolts other than anchor bolts (2) B211 2024-T4 Nuts, 5/16 inch and larger B211 6262-T9 Nuts, 1/4 inch and under, tamper -proof type B211 2024-T4 Washers, Alclad B209 2024-T4 Flange splicing material B209 6061-T6 Post caps and chord caps B26 SG-70A-F Rivets B316 6053-T6 Shims B209 1100-0 Posts clips B308 6061-T6 Letters, numerals, and symbols B209 3003-H14
1.Recycled aluminum flat sheet (sign blanks) meeting ASTM B209, Alloy 6061-T6 or 5052 -H38 may be used for temporary signing only. Select composite material sign blanks (temporary signing only) from the Department’s QPL. The sign blanks shall be flat and shall contain no visible lateral bow.
2.Apply chromated sealed anodic coating at least 0.0002 inch thick to all finished bolts.
916.03 Steel
Use steel conforming to the requirements in Table 916.03 -1, unless otherwise specified: 916.04 984 Table 916.03 -1: Structural Steel and Compo nents Item ASTM Specification Grade Steel structural shapes (1) A709 50 S Steel structural plates (1) A709 36 Posts, chord, and bracing members, galvanized A53 B Post caps and chord caps (1) A27 -- Bolts, nuts, and washers, galvanized A307 --
1.Galvanize in accordance with ASTM A123.
916.04 Stainless Steel
Use stainless steel conforming to the following:
1.Stainless steel bolts, washers and screws: ASTM A193, Austenitic steel.
2.Stainless steel nuts: ASTM A1 94, Grade 8F, except that the nuts shall be lock nuts with semi -finished hex nuts equivalent to American Standard Heavy Series.
916.05 Fabrication
A.General Fabricate all signs and supports as shown on the Plans. Submit departures from the Plans in the form of shop drawings, as specified in
916.05 B. Perform work in a uniform, workmanlike manner.
Complete the fabrication of steel components specified to be g alvanized, including the forming of holes or perforations, prior to galvanization. Fabricate all signs and supports in a plant operated by a fabricator who has the necessary experience to manufacture quality signs and supports meeting these Specifications. Before starting fabrication, provide the Department with the name of the proposed fabricators of the signs and supports, and, if requested by the Department, furnish information as to the fabricator’s qualifications and experience. 916.05 985 B. Shop Drawings For departures from the Plans, submit, for the Engineer’s approval, eight copies of shop drawings showing complete detail designs of such departures and all other information necessary to complete the sign assembly.
C.Flat Sheet Signs Fabricate flat sheet signs of a single piece of sheet aluminum, or composite material (when allowed), without joints and without supporting frame, unless otherwise specified.
D.Multiple Panel Signs Fabricate multiple panel sign s of extruded sections that are 12 inches wide, mounted horizontally, and without vertical joints. Ensure that all panels are flat and straight, and within the commercial tolerances established by the aluminum and composite industry.
E.Overhead Sign Support s Fabricate overhead sign supports in accordance with the Plans and approved shop drawings. Fabricators must be AISC certified as specified in 602.04.A.4. Perform all welding in the shop in accordance with the Plans and the Contract Special Provisions. Provide b rackets for mounting signs (including future signs) of the type to be supported by the structure. They shall be adjustable to allow mounting of the sign faces at any angle between a t ruly vertical position and 3 degrees from vertical. Obtain this angle by tilting the top of the sign toward traffic . All brackets shall be of a length equal to the heights of the signs being supported. Thoroughly clean all steel fabricated components oth er than stainless steel parts, including clamps and brackets, and galvanize by the hot -dip process, meeting the applicable ASTM Specifications specified in 916.03. 916.05 986 F. Cutting (Metals) Saw or mill materials over 1/2 inch thick. M aterials 1/2 inch thick or less may be sheared, blanked, sawed, or milled. Ensure that cut edges are true and smooth and free from excessive burrs or ragged breaks. Fillet re-entrant cuts by drilling prior to cutting. Do not flame cut aluminum.
G.Bolt Holes (In Metals) Either drill or blank bolt holes to finished size, provided the diameter of the blanked hole is at least twice the thickness of the metal being blanked.
H.Preparation of Sign Surfaces Before preparing the surface, complete all fabrication, including cutting, welding, and punching of holes, excluding mounting holes for demountable letters, numerals, symbols, and borders. Before painting or applying reflective sheeting to the aluminum, trea t sign panels in strict accordance with the following procedure:
1.Preliminary Cleaning. Completely submerse the surface in a 6% solution of an inhibited alkaline cleaner at 160 to 180 F for 3 minutes followed by a cold water rinse.
2.Etching. Follow preliminary cleaning with a surface etch by immersing the sign for three minutes in a 6 to 8% dilute phosphoric acid solution followed by spraying with a cold water rinse and immersing for 1 minute in circulating hot water at 180 F.
3.Handling. Do not handle any metal, except by device or clean canvas gloves, between cleaning and etching operations and the application of paint or reflective sheeting. Do not allow the metal to come in contact with grease, oils, or other contaminating substances aft er cleaning and etching and prior to the application of paint or reflective sheeting. Treat composite material sign panels in accordance with the manufacturer’s recommendations. 916.05 987 I. Shop Painting and Reflectorization All legends, borders and background shall be of the color and placed on the sign as shown on the Plans.
1.Application . Apply reflective sheeting to properly treated base panels with mechanical equipment in the manner specified by the sheeting manufacturer. Type II adhesive coated sheeting shall be pre-perforated . For sign faces consisting of two or more pieces or panels of reflective sheeting, carefully match pieces for color at the time of sign fabricatio n to provide uniform appearance and brilliance, both day and night. Apply alternate, successive width sections of either sheeting or panels to be reverse and consecutive to ensure that corresponding edges of reflective sheeting lie adjacent on finished sign. Nonconformance may result in non -uniform shading and an undesirable contrast between adjacent widths of applied sheeting that will not be acceptable. Limit splices. When spliced, overlap Type I adhesive coated sheeting not less than 3/16 inch. Type II adhesive coated sheeting may be spliced with an overlap of not less than 3/16 inch or butted; when butted, ensure that the gaps do not exceed 1/32 inch. Only use butt splices on signs screen processed with transparent color. Extend sheeting applied t o extruded sections over top edges and down side legs a minimum of 1/16 inch. Ensure that, after aging 48 hours at 75 F, adhesion of reflective sheeting to sign surface is strong enough to resist stripping from the panel when tested with a stiff putty kn ife, and will meet other applicable requirements as specified for Reflective Sheeting in 916.06.
2.Silk Screening . Apply all legends and borders on signs, except demountable or cut -out legends and borders, by silk screening after the sheeting is attached to the panels, unless otherwise approved by the Engineer. Perform all screening in a workmanlike manner and as recommended by the manufacturer of the reflective sheeting. The Contractor may apply black legends and borders to signs having silver reflectorized backgrounds by equally effective methods when approved by the Engineer. Use proper size screen mesh in revers e screening to ensure that the finished colors match the prescribed Standard Interstate Colors (AASHTO Manual). Noticeable deviation from the shades is cause for rejection of the sign. 916.06 988 After silk screening, or reverse silk screening, bake the sign in an approved oven for a period of one hour, at a temperature of 200 F.
J.Packaging Package signs in a manner that will prevent damage to any part of the sign, including demountable legends or borders, during shipment and storage. Before pa ckaging, ensure that signs are free of moisture and paints are thoroughly dry. Do not apply adhesive tapes to any sign surfaces. Keep all packaged signs entirely dry. Securely attach braces to all assembled or partially assembled signs, other than flat s heet signs, to prevent buckling or warping from the time of assembling to attaching on permanent supports.
916.06 Reflective Sheeting
Provide reflective sheeting from the Department’s QPL conforming to AASHTO M 268 and the supplementary requirements for fungus resistance of AASHTO M 268. The sheeting material shall have a precoated adhesive backing or a heat and pressure activated adhesive backing protected by a removable liner. For all signs with a SILVER -WHITE and OR ANGE background when used on temporary barricades and channelizing drums, provide reflective sheeting of Type B or better as specified by AASHTO M 268. For all signs with a SILVER -WHITE, YELLOW, RED, GREEN, BROWN, or BLUE b ackground, provide reflective sheeting of Encapsulated Lens or Micro-prismatic Lens material meeting or exceeding the minimum requirements for Type B or better as specified by AASHTO M 268. FLOURESCENT ORANGE background material shall meet or exceed the requirements for Type B, as specified by AASHTO M 268.
916.07 Legends, Borders , and Accessories
Provide letters, numerals, symbols, borders, and route markers conforming to the MUTCD. 916.08 989 A. Type "A" Class I (Demountable) Provide silver-white letters, numerals, symbols, borders, and route markers of a pre -coated pressure sensitive or a tack -free heat-activated adhesive reflective sheeting permanently adhered to the sign panel. The reflective s heeting shall meet the requirements of 916.06 (Type B or better as specified by AASHTO M 268). Mechanically apply the reflective sheeting to the properly prepared sign panel with the equipment and in a manner prescribed by the sheeting manufacturer. Lette rs, numerals, symbols, borders, and route markers shall be 0.032 inch thick aluminum sheet of 3003 H14 Alloy or approved composite material. Properly degrease and etch aluminum, or treat with a light, tight, amorphous chromate type coating. Supply each le tter, numeral, symbol, and route marker with mounting holes, and secure to the sign surface with corrosion -resistant screws, bolts, or rivets.
B.Type "A" Class 2 Cut -Out (Direct Applied Reflective Sheeting Copy) Provide silver -white cut -out letters, numerals, symbols, borders, and route markers of a pre -coated pressure sensitive or a tack -free heat- activated adhesive reflective sheeting. The reflective sheeting shall meet the requirements of 916.06 (Type B or bet ter as specified by AASHTO M 268).
916.08 Flexible Delineator Posts
Provide delineator posts of the height shown on the Plans and of a width that presents a minimum 3 -inch wide profile in the direction of approaching traffic. The top 14 inches of the front of the delineator post shall have a smooth surface capable of read ily bonding the pressure sensitive reflective sheeting. Provide delineator posts that are white in color unless otherwise shown on the Plans. Reflectorize the posts with reflective sheeting that conforms to AASHTO M 268, Type B or better retroreflection performance level. The reflective sheeting strip on the delineators shall be 9 inches long and 3 inches wide profile and facing approaching traffic. Locate the top of the reflective sheeting 1/2 inch from the top of the delineator post. 916.08 990 For Flexible Type II Object Markers, use reflective sheeting consisting of three yellow squares spaced 4 -1/2 inches center to center, each square being 3 inches long with sufficient width to present a 3 -inch wide profile when mounted on a post. Locate the top square 1/2 inch from the top of the object marker post. Select material from the Department’s QPL. The manufacturer shall certify that the materials to be supplied are formulated the same as when tested by the National Transportation Products Evaluation Program and w ill conform to the requirements of this Specification. The Department reserves the right to periodically sample and test delineator posts. 916.08 991 SECTION 917 – ROADWAY AND STRUCTURE LIGHTING MATERIALS
917.01 General Requirements ................................ ................................ .. 991
917.02 Roadway Lighting St andards ................................ ...................... 992
917.03 Lighting Assembly Strength Test ................................ ................ 998
917.04 Wiring ................................ ................................ .......................... 998
917.05 Metallic Conduit ................................ ................................ ......... 999
917.06 Metallic Conduit Fittings ................................ ............................. 999
917.07 Non -metallic Rigid Conduit ................................ ........................ 999
917.08 Luminaires ................................ ................................ .................. 999
917.09 Fittings, Pull Boxes, and Bends ................................ ................ 1000
917.10 Relays, Switches, Control Cabinets, Etc. ................................ ... 1000
917.11 Service Poles and Wood Standards ................................ ........... 1000
917.12 Guying Components ................................ ................................ . 1000
917.13 Grounding Materials ................................ ................................ . 1001
917.14 Splicing Materials ................................ ................................ ..... 1001
917.15 Drag Wire ................................ ................................ ................. 1001
917.16 Photoelectric Relay ................................ ................................ .... 1001
917.01 General Requirements
Prior to making any purchases, submit for approval a complete list of all proposed materials. Include on the list the manufacturer’s name, catalog number, and such other defin itive or descriptive data as is necessary to adequately define the item. When requested by the Engineer, furnish samples of the material and notarized certificates by the manufacturer that the material meets the requirements of these Specifications and al l industry standards referred to herein. Obtain all guarantees on mechanical and electrical equipment furnished by the manufacturer and submit them to the Engineer. The Engineer will then transmit these guarantees to the agency responsible for future main tenance of the equipment.
Source: Tennessee Standard Specifications for Road and Bridge Construction, 2021 Edition. Pages 991–999 of 1,072.