525 ALASKA 2020 SECTION 730
730-2.01 SHEET ALUMI NUM . Use alloy 6061- T6, 5052- H36, 5052- H38, or recycled aluminum
meeting alloy 3105, as specified in ASTM B209. Verify alloy and temper designations by mill certification. Treat the aluminum base metal sheets with a rinsed non- hexaval ent chromium conversion coating for aluminum and aluminum alloys that meets ASTM B921, class one. Handle the cleaned and coated base metal only by a mechanical device or by operators wearing clean cotton or rubber gloves. After cleaning and coating operati ons, protect the panels at all times from contact or exposure to greases, oils, dust or other contaminants. Make each sign panel a continuous sheet for all lengths 72 inches or less in the horizontal direction. Use no more than one vertical splice for signs up to 144 inches in length and 48 inches or less in height. Meet the panel dimensions specified with a tolerance of 1/16 inch. Furnish metal panels that are cut to size and shape and free of buckles, warp, dents, cockles, burrs and any other defects resulting from fabrication. Complete all possible fabrication, including shearing, cutting and punching of holes prior to the base metal preparation.
730-2.02 HIGH DENSIT Y OVERLAID PLYWOOD. Construct plywood sign panels, for
Construction and Maintenance Signs, of high density plywood, exterior type Grade B -C or better. Meet the requirements in PS 1- 66 Products Standard for Softwood Plywood, Construction and Industrial published by the Products Standards Section of the U.S. Department of Commerce. Use high dens ity type overlay, with the following properties:
1.Minimum weight of 60 pounds per thousand square feet of surface
2.Minimum thickness of 0.012 inch before pressing
3.Contain a minimum resin content of 45 percent based on the dry weight of the impregnated fiber
4.Contain sufficient resin content to bond itself to the plywood Single Panel Signs Thickness, inches, Minimum Up to and including 18 inches wide 3/8 Over 18 inches wide 1/2 Plywood shields on destinations signs 3/8 Multiple Panel Signs 5/8 Prime the sign back with one coat of white exterior enamel undercoat and finish with one coat of white exterior enamel. Use primer recommended by the supplier of the finish coat which is completely compatible. Before applying reflective sheeting:
5.Clean the surf ace thoroughly with lacquer thinner, heptane, benzene, or solvent recommended by sheeting manufacturer.
6.Sand the surface with light sandpaper or steel wool and wipe dry and clean with clean cloth.
730-2.03 RETROREFLEC TIVE SHEETING. Meet ASTM D4956 for the type specified.
526 ALASKA 2020 730-2.04 SIGN POSTS. Use the type and size of posts designated on the Plans.
1.Metal Pipe Posts.
a.Fabricate from steel pipe to meet ASTM A53 Standard Weight (Schedule 40), Type E or S, Grade B. Furnish square posts with 7/16 inch diameter holes drilled or punched as necessary to permit mounting of the sign.
b.Hot dip galvanize to meet AASHTO M 111 after fabrication. When cutting metal posts after hot dip galvanizing, minimize damage to the zinc coating and protect all exposed surfaces by treating the exposed area.
c.Repair galvanized surfaces that are abraded or damaged at any time after the application of the zinc coating to meet the applicable provisions of AASHTO M 36.
2.Perforated Steel Posts.
a.Fabricate posts from 0.105- inch (12 gauge) thick cold-rolled carbon steel sheets, commercial quality, to meet ASTM A653 and ASTM A924. Zinc coat, both sides, to meet coating designation G90. Form posts into a steel tube, roll to size, and weld in the corner.
b.Perforate all members for their entire lengt h with 7/16 inch diameter holes on 1 inch centers.
c.Furnish members that are straight and with a smooth, uniform finish, with no splices.
d.Ensure that all perforations and cut off ends are free from burrs.
e.Ensure that consecutive sizes will telescope freel y with a minimum of play.
3.Finished Wooden Posts.
a.Meet AASHTO M 168, except limit the sweep (circular deviation from a straight line) to 0.08 foot in 10 feet.
b.Pressure treat wooden posts with a preservative registered with the US Environmental Protection Agency, conforming to the requirements of AASHTO M 133 or AWPA Standard U1 Commodity Specification A (Sawn Products) for soil and freshwater applications meeting Use Category 4B. Use the methods specified in Section 714. Meet the minimum retention of preservative specified according to AWPA Standard U1, Commodity Specification A: Sawn Products.
c.Treat all field cuts and holes in wooden posts by thoroughly swabbing, spraying or brushing with two coats of a preservative conforming to AWPA Standard M4.
4.Wide Flange Posts.
a.Steel. Meet ASTM A36.
b.Hot dip galvanize to meet AASHTO M 111 after fabrication. When cutting galvanized metal posts, minimize damage to the zinc coating and treat the exposed area as follows.
c.Repair galvanized surfaces that are abraded or dam aged at any time after the application of the zinc coating to meet the applicable provisions of AASHTO M 36.
5.Flanged Channel Posts. Use either of the following:
a.Aluminum meeting ASTM B221, alloy 6061- T6. 527 ALASKA 2020 b. Steel meeting ASTM A36. Galvanize steel posts per AA SHTO M 111.
6.Square Non- Perforated Steel Tubes.
a.Fabricate from 3/16 inch thick cold- rolled carbon steel sheets, commercial quality, to meet ASTM A500, Grade B. Form posts into a steel tube, roll to size, and weld in the corner. Furnish with 7/16- inch diameter holes drilled or punched as necessary to permit mounting of the sign.
b.Hot dip galvanize to meet AASHTO M 111 after fabrication. When cutting metal posts after hot dip galvanizing, minimize damage to the zinc coating and protect all exposed surfaces by treating the exposed area.
c.Repair galvanized surfaces that are abraded or damaged at any time after the application of the zinc coating to meet the applicable provisions of AASHTO M 36.
730-2.05 FLEXIBLE DE LINEATOR POSTS. Durable fiberglass composite or plastic material
meeting the dimensions and colors shown on the Plans. Resistant to ultraviolet light, ozone and hydrocarbon damage and remain flexible at a temperature of minus 40 °F. Provide posts with reflectors that are capable of self -erecting and rem aining serviceable after 5 head- on impacts at 55 mph and 10 impacts at 35 mph with an automobile at an air temperature of plus 40 °F.
730-2.06 ACRYLIC PRI SMATIC REFLECTORS. Meet AASHTO M 290 and the dimensions and
colors shown on the Plans.
730-2.07 SIGN S UPPORT FASTENERS. Meet the following:
FASTENER SPECIFICATION TABLE FASTENERS STEEL STAINLESS STEEL Bolts ASTM A307 ASTM F593 Nuts ASTM A563 ASTM F594 Washers ASTM F844 ASTM A480 528 ALASKA 2020 SECTION 731 WATERPROOFING MEMBRA NE
731-2.01 SPRAY -APPLI ED WATERPROOF ING MEMBRANE . Meet the requirements in Table
731-1. TABLE 731 -1 SPRAY -APPLIED WATERPROOFING MEMBRANE
731-2.02 SHEET WATER PROOFING MEMBRANE . Meet the requirements in Table 731- 2.
TABLE 7 31-2 SHEET WATERPROOFING MEMBRANE Test Requirements Test Method Adhesion to Concrete 100 psi min., with failure in concrete ASTM D4541 Tensile Strength at Break 1500 psi min. ASTM D638 Elongation at Break 130% min. ASTM D638 Crack Bridging Pass at 10 cycles of 1/8 inch when tested at -15°F ASTM C1305 Interlayer Shear Strength 40 psi min. AASHTO TP -114 Test Requirements Test Method Tensile Strength at Break 50 lbs/inch min. ASTM D882 Elongation of Membrane at Break 300% min. ASTM D882 Puncture Resistance 200 lbs min. ASTM E154 Permeability 0.05 perms max. ASTM E96 Flexibility Pass ASTM D146
Source: Alaska Standard Specifications for Highway Construction, 2020 Edition. Pages 553–555 of 584.