Section 633.-TRAFFIC CONTROL SIGNS AND DELINEATORS Description 633.01 This work shall consist of furnishing and installing traffic delineators, signs, sign supports, framing and panels, all in accordance with these specifications, and in reasonably close conformity with the locations, lines, grades and details shown on the plans. 633.02 Traffic control sign details not shown on the plans shall be in conformity with the "Manual on Uniform Traffic Control Devices for Streets and Highways," published by the U.S. Department of Transportation, Federal Highway Administration. Sign supports and framing members shall be in accordance with the "Specifications for the Design and Construction of Structural Supports for Highway Signs" as approved and published by the American Association of State Highway and Transportation Officials. Materials 633.03 Sign Panels. Sign panels shall be made from wood, sheet steel, or sheet aluminum as specified which have the face side reflectorized. (a) Plywood panels. The panels shall be exterior type B-B high density overlay plywood or better, conforming to National Bureau of Standards PS 1-66. (b) Aluminum panels. All sheets and plates shall conform to the requirements of ASTM B 209, alloy 6061-T6. For large signs laminated honeycomb aluminum sign panels may be used. Extruded aluminum sign panels shall conform to the requirements of ASTM B 221, Alloy 6063-T6. (c) Steel panels. Sheet steel blanks shall be 14 gauge continuous coat galvanized and conform with ASTM A 525. Zinc coating shall be designation G90 and in addition all sheet steel shall be mill phosphatized to a thickness of 100 ± 50 milligrams per square foot of surface area. 633.04 Posts. Posts shall be either wood, aluminum or steel as specified. (a) Wood posts. Wood posts shall be dry No. 1 grade, S4S, Douglas Fir, Southern or Ponderosa Pine, Hemlock, Spruce, Western Larch, or other wood acceptable to the Engineer, meeting the requirements of Subsection 716.03. (b) Steel posts. Steel posts shall be billet or rail steel conforming to the requirements of ASTM A 499, galvanized in accordance with ASTM A 123. Minimum weight per foot will be as shown on the plans. The posts shall have 3⁄4-inch holes drilled or punched, before galvanizing, along the centerline of the web. The punching or drilling should begin 1-inch from top of post, at 1-inch centers for the entire length of the post. (c) Aluminum Posts. Aluminum posts shall be standard shapes as specified and shall be aluminum alloy 6061-T6, 6351-T5, 6063-T6 or 6005-T5 conforming to ASTM B 221. 633.05 Fittings. Lag screws, washers, clip angles, wood screws, shear plates, U-bolts, clamps, bolts, nuts and other fasteners shall be galvanized steel, aluminum alloy, or as specified by the Engineer or as shown on the plans. All exposed surfaces shall be painted the same color as the area surrounding the part exposed. Galvanizing of steel hardware shall be in accordance with ASTM A 153. High strength steel bolts, nuts and washers shall conform to ASTM A 325, except as noted on the plans. 633.06 Sheet Reflective Materials. Type I, Type II, Type III and Type IV reflective sheeting. (a) Description Reflective sheeting shall consist of a retroreflective lens system having a smooth outer surface. When adhesive backing is used the sheeting shall have a precoated adhesive on the backside protected by an easily removable liner. Types I ance in terms of reflective intensity. (b) Color Requirements IV refer to levels of perform (1) The colors specified shall be matched visually and shall be within the color tolerance limits shown on the appropriate Highway Color Tolerance Charts issued by the Federal Highway Administration utilizing the instructions thereon. Certification as to conformance with this requirement may be accepted by the purchaser. (or) (2) Through instrumental color testing the diffuse day color of the reflective material shall conform to the requirements of Table I or II and shall be determined in accordance with ASTM E 97, "Standard Method of Test for 45-Degree, 0-Degree Directional Reflectance of Opaque Specimens by Filter Photometry." (Geometric characteristics must be confined to illumination within 10 degrees of, and centered about, a direction of 45 degrees from the perpendicular to the test surface; viewing is within 15 degrees of, and center about, the perpendicular to the test surface. Conditions of illumination and observation must not be interchanged.) The standards to be used for reference shall be the MUNSELL PAPERS designated in Table I and II The papers must be recently calibrated on a spectrophotometer. The test instrument shall be one of the following or approved equal: 1. GARDNER Multipurpose Reflectometer or Model XL20 Color Difference Meter. 2. GARDNER Model AC-2a Color Difference Meter or Model XL30 Color Difference Meters. 3. MEECO Model V Colormaster 4. HUNTERLAB D25 Color Difference Meter (c) Reflective Intensity The reflective sheeting shall have minimum Specific Intensity per unit area (SIA) as shown in Tables III, IV, V, or VI expressed as "candelas per footcandle per square foot" [(C.d fc -1) ft. -2]. Four levels of performance relative to SIA are available to be selected by the purchaser for specific uses. Measurement of SIA shall be conducted in accordance with the method detailed in Section 718. (d) Specular Gloss The reflective sheeting shall have an 85 degree specular gloss of not less than 40 for types I and II, and not less than 50 for III-IV, when tested in accordance with ASTM D 523. (e) Color Processing The sheeting shall permit cutting and color processing with compatible transparent and opaque process inks in accordance with the Manufacturers recommendation at temperatures of 60°F to 100°F and relative humidity R.H. at 20 to 80 percent. The sheeting shall be heat resistant and permit force curing without staining of applied or unapplied sheeting at temperatures as recommended by the manufacturer. Color processing for Type III material shall be restricted to sheeting with heat activated adhesive backing unless otherwise recommended by the manufacturer. (f) Shrinkage A 9 inch by 9 inch reflective sheeting specimen with liner shall be conditioned a minimum of 1 hour at 72°F and 50 percent relative humidity. The liner shall be removed and the specimen placed on a flat surface with the adhesive side up. Ten minutes after liner is removed and again after 24 hours, the specimen shall be measured to determine the amount of dimensional change. The reflective sheeting shall not shrink in any dimension more than 32 inch in 10 minutes nor more than 8 inch in 24 hours. (g) Flexibility Types I and II Sheeting Material: The sheeting, applied according to the manufacturer's recommendations to a clean, etched 0.020 inch by 2 inch by 8 inch aluminum panel of alloy 6061-T6 conditioned a minimum of 48 hours and tested at 72°F and 50 percent relative humidity shall be sufficiently flexible to show no cracking when bent around a 3⁄4 inch mandrel. *The four pairs of chromaticity coordinates determine the acceptable color in terms of the CIE 1931 standard colorimetric system measured with standard illumination source C. **Silver white is an acceptable color designation. ***Available from Munsell Color Company: 2441 Calvert St.. Baltimore, MD, 21218. *The four pairs of chromaticity coordinates determine the acceptable color in terms of the CIE 1931 standard colorimetric system measured with standard illumination source C. Type III and IV Sheeting Material: The sheeting, with the liner removed and conditioned for 24 hours at 72°F and 50 percent R. H., shall be sufficiently flexible to show no cracking when slowly bent, in one second's time, around a 8 inch mandrel with adhesive contacting the mandrel. NOTE: For ease of testing, spread talcum powder on adhesive to prevent sticking to the mandrel. Non-adhesive sheetings shall show no signs of cracking or crazing when flexed repeatedly over a 1/16 inch mandrel to 180° at 72°F. (h) Adhesive The reflective sheeting shall include a pre-coated pressure sensitive adhesive backing (Class 1) or a tack-free heat activited adhesive backing (Class 2) either of which may be applied without necessity of additional adhesive coats on either the reflective sheeting or application surface. The Class 1 adhesive shall be a pressure sensitive adhesive of the aggressive tack type requiring no heat solvent or other preparation for adhesion to smooth clean surfaces. The Class 2 adhesive backing shall be a tack-free adhesive activated by applying heat in excess of 175°F to the material as in the heat-vacuum process of sign fabrication. The protective liner attached to the adhesive shall be removed by peeling without soaking in water or other solvents without breaking, tearing or removing any adhesive from the backing. The protective liner shall be easily removed following accelerated storage for 4 hours at 160°F under a weight of 2.5 pounds per square inch. The adhesive backing of the reflective sheeting shall produce a bond to support a 13⁄4 pound weight for 5 minutes, without the bond peeling for a distance of more than 2.0 inches when applied to a smooth aluminum surface and tested as specified in Section 718. (i) Impact Resistance Types I, II and III reflective sheeting material, applied according to the manufacturer's recommendations to a cleaned, etched aluminum panel of alloy 6061-T6, 0.04 inches by 3.0 inches by 5 inches and conditioned for 24 hours at 72°F and 50 percent R.H., shall show no cracking when the face of the panel is subjected to an impact of a 2.0 pound weight with a % inch rounded tip dropped from a 10 inch pound setting on a Gardner Variable Impact Tester, 1G-1120. For Type IV material a 100-inch-pound setting should be used. (j) Accelerated Weathering When applied in accordance with recommended procedures, the reflective material shall be weather resistant and, following cleaning in accordance with manufacturers recommendations, shall show no appreciable discoloration, cracking, blistering or dimensional change. Following exposure, the panels shall be washed with a 5% HCl solution for 45 seconds, rinsed thoroughly with clean water, blotted with a soft clean cloth, brought to equilibrium at standard conditions and tested. It shall have not less than the percent of the minimum SIA specified in the table below when subjected to accelerated weathering in accordance with ASTM G23, Type E or EH Weatherometer with the humidifier off. *For orange material having glass bead retro-reflective elements, the hours tested shall be 500. (k) Intended Use The reflective sheeting specified herein is intended for use on surfaces of highway signs and other traffic control devices to assure their optimum visibility by day and at night when exposed to a light source and whether dry or totally wet by rain. |