Purchasers should select colors and preferred options permitted herein and specify (1) the desired level of SIA (Type I, Type II, Type III or Type IV) as appropriate for anticipated use and durability, and (2) the type of adhesive backing (class 1, precoated pressure sensitive adhesive or class 2, heat activated adhesive) or other type of non-adhesive backing as required.

633.07 Letters, Numerals, Arrows, Symbols, Border. Letters, numerals, arrows, symbols, border, and other features of the sign message shall be of the type, size, and series shown on the plans or as specified by the Engineer.

Colors shall be as specified in subsection 633.06. Completed letters, numerals, and other units shall be formed to provide continuous stroke width with smooth edges and shall present a flat surface free of warp, blisters, wrinkles, burrs, and splinters. Units of the sign message of the type shown on the plans shall meet the following requirements.

Type L-1: SCREEN PROCESS, APPLIED

The letters, numerals, arrows, symbols, and border, shall be applied on the reflective sheeting or opaque background of the sign by direct or reverse screen process. Messages and borders of a color darker than the background shall be applied to the paint or the reflective sheeting by direct process. Messages and borders of a color lighter than sign field shall be produced by the reverse screen process.

Opaque or transparent colors, inks, and paints used in the screen process shall be of the type and quality recommended by the manufacturer of the reflective sheeting.

The screening shall be done in a manner which results in a uniform color and tone, with sharply defined edges of legend and border and without blemishes on the sign background that will affect intended use.

Signs after screening shall be air-dried or baked in accordance with manufacturer's recommendations to provide a smooth hard finish. Any signs on which blisters appear during the drying process shall be rejected.

Type L-2: DEMOUNTABLE LETTERS, NUMERALS, ETC.

The letters, numerals, symbols, border and other features of the sign message shall be reflective sheeting applied to flat aluminum prepared as in 633.11 with the equipment and in a manner prescribed by the sheeting manufacturer. Letters, numerals, symbols and borders shall be 0.032 inch thick aluminum sheet of 3003-H14 alloy, ASTM B 209. Spacing of mounting holes for screws, bolts, or rivets shall be determined by character size and shape but in no case shall be more than 8 inches on center. Each character shall be secured to the sign with non-twist, corrosion resistant screws, bolts, or rivets.

Type L-3: DIRECT APPLIED CHARACTERS

The letters, numerals, symbols, border and other features of the sign message shall be cut from Type II or Type III reflective sheeting (Section 633.06) of the color specified on the plans and applied to the reflective sheeting of the sign field in accordance with instructions of manufacturer of reflective sheeting.

The reflective sheeting shall have minimum SIA specified in Tables IV or V of subsection 633.06.

Type L-4: ACRYLIC PLASTIC CHARACTERS

The letters, numerals, symbols, borders and other features of the sign message shall consist of embossed aluminum frames in which prismatic reflectors are installed so as to be an integral part of the character or otherwise affixed to prevent their displacement in handling

or service. Reflectors which are held in the frames by means of tape or adhesive will not be accepted. All items shall be fabricated from 0.040 inch sheet aluminum alloy 3003-H14, ASTM B 209. Mounting holes shall be provided within frames to permit the use of screws, rivets, or other common fasteners. The size and spacing of reflector holes shall be such as to afford maximum night legibility and visibility to the finished cut-out figure.

The reflectors shall consist of a clear and transparent plastic face (herein referred to as the lens) and an opaque back fused to the lens (under heat and pressure) around the entire perimeter to form a homogeneous unit permanently sealed against dust, water, and water vapor. The reflector shall be colorless, yellow, or red, as specified. The lens shall consist of a smooth front surface free from projections or indentations other than for identification and a rear surface bearing a prismatic configuration such that it will effect total internal reflection of light. The manufacturer's trademark shall be molded legibly into the face of the lens. The specific brightness of each reflex reflector intended for use in cut-out letters, symbols, and accessories shall be equal to or exceed the following minimum values with measurements made with reflectors spinning. Five reflectors shall be submitted for test for brightness. Failure of one or more subjected to test shall constitute failure of the lot.

For yellow reflectors the specific brightness minimum shall be 60 percent and for red it shall be 25 percent of the value shown for crystal.

The following test shall be used to determine if a reflector is adequately sealed against dust and water. Submerge five samples in a water bath at room temperature. Subject the submerged samples to a vacuum of 5 inches gage (water) for 5 minutes, then examine them for water intake. Failure of one or more shall constitute failure of the lot. Three reflectors shall be tested for 4 hours in a circulating air oven at 175°F ± 5°. The test specimens shall be placed in a horizontal position on a grid or perforated shelf permitting free air circulation. At the conclusion of the test the samples shall be removed from the oven and permitted to cool in air to room temperature. The samples, after exposure to heat, shall show no significant change in shape and general appearance when compared with unexposed control standards. No failure will be permitted. The assembled cut-out letter, symbol, or accesory shall withstand the combined corrosion test set forth in ASTM B 117.

633.08 Concrete. All concrete shall conform to Section 602 Minor Concrete Structures. 633.09 Reinforcing Steel. Reinforcing steel shall conform to the requirements of Section 554.

633.10 Delineators. The materials to be used for the delineators assembly shall be as specified in 712.14. Supporting posts shall be steel, aluminum, wood or plastic as specified.

Construction Requirements

633.11 Fabrication of Sign Panels. Fabrication of all parts shall be accomplished in a uniform and workmanlike manner. All panel fabrication, including cutting, punching, and drilling of holes, shall be completed prior to final surface preparation and application of reflective sheeting except where required for the fabrication of diecut or sawed letters on processed and mounted signs. Metal panels shall be cut to size and shape and shall be free of

buckles, warp, dents, cockles, burrs, and defects resulting from fabrication. The surface of all sign panels shall be flat.

Field drilling of holes in any part of the structural assembly will not be permitted without approval of the Engineer.

(a) Aluminum Panels.—Aluminum sign panels shall be fabricated from standard widths of aluminum sheet. The thickness for panel sizes of 30 inches by 30 inches or smaller shall be 0.080-inch and the thickness of larger panels shall be 0.125-inch unless otherwise shown on the plans.

The blanks shall be cleaned, degreased, and chromated or otherwise properly prepared in accordance with approved methods recommended by the sheeting manufacturer.

(1) Ground Mount and Overhead Laminated Honeycomb sign panels.

Sign panels shall be made in lengths up to 24 feet and may be mounted vertically or horizontally. Maximum width shall be 5 feet for panels up to 12 feet long; panels over 12 feet long shall have a maximum width of 4 feet and minimum width for all panels shall be 2 feet. Size graduations shall be made in 6-inch increments in both width and length. Thickness of the honeycomb panels shall be 1 inch or 2-1⁄2 inches. Where two or more panels comprise one sign, not more than two panel widths shall be used with the dissimilar panel or panels positioned at the edge of the completed sign. Vertical height of panels shall be of sufficient size to insure a minimum amount of legend appearing at any panel joint. The maximum span between supports on 1-inch panel shall not exceed 9 feet and overhang at each end not to exceed 3 feet. The maximum span between supports for 2-2 inch panels shall not exceed 14 feet 6 inches and overhang shall not exceed 4 feet 9 inches.

(2) Panel Construction

a. Face and back sheets to be fabricated in one piece from aluminum alloy 3003-H14. The surface shall be treated with an amorphous chromate conversion coating conforming to the requirements of Sect. 5, "Recommended Processing Methods," ASTM B 449, Class 2, Coating (10-35 mg./sq. ft.) with a median of 25 mg./sq. ft. as the optimum coating weight.

b. Each panel section shall be provided with a perimeter frame. All perimeter framing shall be aluminum alloy 6063-T6. The extruded horizontal top and bottom frame members shall have an integral retainer track for affixing mounting bolts to provide for blind fastening of sign panel to post support. The extruded vertical side frame members shall be a channel. An additional slot shall be milled in the top and bottom frame for later field insertion of post clip bolts. The perimeter frame shall be assembled by means of self-tapping hex head stainless steel screws. A sealant shall be used at the corner to prevent moisture penetration.

If the horizontal finished dimension of the sign exceeds 24 feet and vertical panels are used, the vertical extruded frame members shall have an integral retainer track for mounting bolts. The horizontal frame members shall be extruded channels.

c. Core material shall be 1 inch or 2-2 inches thick, as required, and shall be phenolic impregnated paper honeycomb. Core material shall meet specification MIL-E-5272 for resistance to fungus. The cell size shall be 1⁄2 inch, weight of Kraft paper 80 pounds, and impregnation 18 percent by weight minimum.

d. The laminating adhesive shall produce a permanent oil and water resistant bond. Adhesives shall be of the thermo-setting type. Bonding of panels shall be done in a heated flat platen press of sufficient size to contain the entire panel at one time with capabilities of 10 p.s.i. over the entire platen area.

All adhesively bonded panels shall have an exterior face of such flatness that when measured at normal room temperature of 70° to 80°F. the maximum wave slope of the surface at any point, measured from the nominal plane of the surface, shall not exceed 1 percent. Flatness will be considered satisfactory if tolerance requirement is met with readings taken in sun or shade. Wave slope shall be computed in the following manner: Measure the distance between high points (dimension A). Place a straight edge across the points and measure the

depth of slope (dimension B). Divide one half of A into B to determine percentage of wave slope.

The manufacturer shall furnish a certification, if requested, as to prior testing of the adhesive laminate according to test methods ASTM E 72 and ASTM C 273 performed by an independent testing laboratory.

e. Tensile strength of the honeycomb laminate construction shall have a minimum of 50 p.s.i. Test to be performed in accordance with ASTM C 297 and ASTM C 481.

f. Weep holes 8 inch in diameter are to be drilled in the perimeter frame at the bottom of each panel. Holes to be spaced approximately 3 inches in from either end and in the center of each panel.

g. Where multiple panels adjoin, the face and edges shall be milled to a tolerance of plus 432 inch or minus 32 inch from a straight plane, so that when two adjoining panels are assembled, no gap over 16 inch shall be visible between panels. Panels may be milled up to 4 inch on each side in order to achieve edge uniformity.

On the perimeter of the finished sign, a 1⁄4 inch tolerance from flush between the sheets and frame will be allowed, and all edges shall be straight within 8 inch from a straight plane. All sharp edges that would present a hazard in handling shall be smoothed.

h. Seam Closure Extrusion-On multiple panel signs, the closure between panels shall be provided by the manufacturer. Extrusions shall be provided from type 6063-T6 aluminum. Tolerances shall be as shown on the plans. Seam closure extrusion to be set in 3 inches from edge of panels for clearance of rivets and frame.

(b) Steel Panels.-The finished plate for the steel panels shall be free of twist of buckle and the background shall be substantially a plane surface. The finished sign panel shall be of continuous coat mill galvanized phosphate coated steel that conforms with Section 633.03(c). The panels shall be cleaned, degreased, or otherwise prepared in accordance with approved methods recommended by the sheeting manufacturer.

(c) Plywood Panels.-The face of the plywood panel shall be abraded and cleaned and degreased in accordance with approved methods recommended by the manufacturer of the reflective sheeting. The edges of the plywood panel shall be properly sealed and the thickness shall be as shown on the plans or as approved by the Engineer.

633.12 Construction of Footings. All excavation shall be performed in accordance with Section 206.

Footings shall be constructed to the details and dimensions shown on the plans or as approved by the Engineer.

633.13 Erection of Sign Supports. Sign supports shall be erected plumb, and in accordance with the details shown on the plans. Lengths of supports will be determined at time of stake out.

633.14 The delineator post shall be driven at locations and to the depth called for on the plans. The delineator housing shall be attached to the post in accordance with the manufacturers' direction.

633.15 The sign panels shall be securely fastened to the posts as shown on the plans or as specified by the Engineer.

Sign panels shall be mounted with the legend horizontal.

To reduce specular glare the sign panel face shall be erected in accordance with the MUTCD.

An insulating material 16-inch thick conforming to Mil-P-15035, Type FBM, FBG, or FBE shall be placed to prevent contact between aluminum and steel material.

Care shall be exercised during all fabrication, shipping, and erection operations to avoid scratchings, abrading, and denting of any parts. The structures shall be handled in such a manner as to avoid any damage thereto.

Damaged parts will be repaired or rejected as directed by the Engineer.

Method of Measurement

633.16 Posts. The quantity to be paid for shall be the number of linear feet of posts furnished, erected and accepted, including all hardware, footings, excavation and other incidentals.

633.17 Sign Panels. The quantity to be paid for shall be the square foot area of sign panels or per each furnished, completed and accepted.

Delineators will be paid per each type specified, furnished, completed and accepted.

Basis of Payment

633.18 The quantities determined as provided above, will be paid for at the contract price per unit of measurement, respectively, for each of the particular pay items listed below that is shown in the bid schedule, which prices and payment shall be full compensation for the work prescribed in this section.

634.01 This work shall consist of applying traffic markings on the finished paved area in accordance with these specifications, at the locations and of the dimensions shown on the plans, or as directed by the Engineer.

Details now 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.

Materials

634.02 The following materials are in general use for pavement markings. In addition to wet applied paints, the other materials listed are often specified for reasons of extended durability, performance or convenience. In the selection of materials for a project, engineering consideration should be given to overall performance needs, traffic volume and type, climatic conditions, available installation procedures and maintenance requirements.

(a) Traffic paint shall conform to the requirements of AASHTO M 248, Type III. Glass beads shall conform to the requirements of AASHTO M 247, Type 1, moisture resistant with flotation properties.