SECTION 832 SIGN POSTS
832.01 GENERAL. This section covers the material requirements for Type I and II sign
posts. Type I posts are perforated square steel tube (PSST) sign posts. Type II posts are U- channel sign posts. Provide posts in lengths as specified in one foot increments with a tolerance of one inch. Sign support systems shall be successfully crash tested in accordance with NCHRP Report 350 or be Manual for Assessing Sa fety Hardware (MASH) certified. Ensure that posts are straight, smooth, and free from any defects affecting their strength, durability, or appearance. Ensure th at all holes and ends are free from burrs and sharp edges and that ends are cut square.
832.02 TYPE I SIGN POSTS. Use hot rolled carbon sheet steel of structural quality that
conforms to ASTM A 1011, Grade 50 minimum. Posts shall have a minimum yield strength of 60,000 psi after cold-forming.
832.02.01 Fabrication. Fabricate the post from square tube formed of steel, rolled to
size and welded directly in the corner by high frequency resistance welding and externally scarfed to agree with corner radii. Provide the following sizes: Provide 7/16-inch diameter holes on the centerline of all 4 sides, space on one-inch centers along the entire post length beginning 1 inch from the top. Ensure holes are in true alignment and opposite each other directly and diagonally. Ensure consecutive sizes of square tubes will freely telescope for 10 feet or more of their length without the necessity of matching any particular face to any other face.
832.02.02 Finish. Conform to ASTM A 653, G90, Structural Quality, Grade 340,
Class 1. Galvanize both the interior and the exte rior of the post. Coat the corner weld with zinc after the scarifying operation. Coat the steel with a chromate conversion coating and a clear organic polymer topcoat.
832.02.03 Tolerances. The Department may reject material falling outside any of the
following tolerances:
A.Outside Dimensions. 0.010 inch. Measure at least 2 inches from the end of the tube.
B.Wall Thickness. 0.011 inch.
C.Holes. 0.016 inches in diameter.
D.Convexity and Concavity. Ensure that no sides exceed 0.01 inch. Measure in the center of the flat side relative to the corner.
E.Square. Ensure sides are 90 degrees to each other within 0.015 inch.
F.Twist. Ensure twist does not exceed 0.075 inch in any three-feet length.
G.Straight. Ensure deviation does not exceed 1/16 th of an inch in any three-feet length.
H.Corner Radii. 5/32 0.016 inch. Outside Dimensions (in.) Corner Radii (in.) Wall Thickness Gauge (in.) Weight (lb/ft) 2 by 2 5/32 12 (0.105) 2.42 2 ¼ by 2 ¼ 5/32 12 (0.105) 2.77 2 ½ by 2 ½ 5/32 12 (0.105) 3.14 832-1
832.02.04 Type D Breakaway Supports. When omni-directional breakaway
supports are required for Type I posts, use Type D breakaway supports from the Department’s List of Approved Materials.
832.03 TYPE II SIGN POSTS. Use hot wrought steel conforming to the physical
properties of ASTM A 499-89, Grade 60 minimum, and conforming to the chemical requirements of ASTM A 1 for rails of nominal weight of 91 lbs per yard or greater. Posts shall have a minimum yield strength of 60,000 psi. For permanent sign installations, use Type II posts that weigh 3 lbs/ft. Type II sign posts that do not comply with these properties may be furnished if approved by the Engineer. If alternative posts are desired, submit a written request for approval and include a description of the physical and chemical properties of the proposed sign posts. Include documentation that the proposed sign support system has been successfully crash tested in accordance with NCHRP Report 350 or Manual for Assessing Safety Hardware (MASH) certified.
832.03.01 Fabrication. Fabricate posts from uniform, modified, flanged channel
sections. Provide 3/8-inch diameter holes on the centerline, space on one-inch centers along the entire post length beginning one inch from the top. Align holes horizontally and vertically to accommodate back to back post installations. Ensure that the area of contact between the posts and sign is symmetrical about the vertical axes of both sign and post and that the back side furnishes a solid bearing surface the entire length of the post for back to back installation.
832.03.02 Deflection. Test for deflection as simple beams, with the flanges in
compression, on non-restricting supports 2 feet apart. Apply a load of 3,500 pounds at the center of the span at a deflection rate not to exceed 0.3 inch per minute. Transmit the load to the beam through a one-inch minimum diameter pin laid across the flanges. With the designated load applied, ensure that the deflection at the center does not exceed 0.18 inch. One minute after removal of the load, ensure that the deflection does not exceed 0.018 inch.
832.03.03 Finish. Galvanize according to ASTM A 123 after fabrication.
832.03.04 Lap Splices. If splicing of Type II posts is desired or necessary (based on
manufacturer’s recommended installation proc edures), provide recommended splice detail from the post manufacturer. Splices shall be su ccessfully crash tested in accordance with NCHRP Report 350 or be Manual for Assessing Safety Hardware (MASH) certified. Splicing of Type II posts shall require the approval of the Engineer.
832.03.05 Omni-Directional Breakaway Supports. When omni-directional
breakaway supports are required for Type II posts, use supports that are recommended by the post manufacturer of the posts. Omni-dir ectional supports shall be successfully crash tested in accordance with NCHRP Report 350 or be Manual for Assessing Safety Hardware (MASH) certified. Use of omni-directional br eakaway supports with Type II posts shall require the approval of the Engineer.
832.04 PACKAGING. Securely fasten posts of the same type and length in bundles of
2,000 pounds or less in a manner that is easily handled by a fork lift and that prevents slipping during handling and shipping. The Engineer will reject posts whose finish is excessively damaged due to slipping, rubbing, or other reasons.
832.05 CERTIFICATION. Submit manufacturer’s certification stating conformance to
the requirements of this section for each shipment of sign posts. Include documentation regarding manufacturer’s recommended installation procedures and NCHRP 350 compliance or MASH certification. Prov ide manufacturer’s certification to the requirements of this section for any splicing or omni-directional breakaway supports used 832-2 with Type II posts.
832.06 ACCEPTANCE. The Department will accept sign posts based on conformance
of the manufacturer’s certification. The Department reserves the right to sample and test sign posts at the Engineer’s discretion. 832-3 SECTION 833 SIGN SUBSTRATES
833.01 Aluminum.
833.01.01 Panel Signs. Conform to ASTM B 221, Alloy 6063-T6. Fabricate signs
from 12-inch wide extrusions and, if specified, compatible 6-inch wide extrusions. When a 6-inch extrusion is specified, use it as the bot tom panel of the sign. Typical cross sections and minimum weights per foot are specified in the Plans. Use compatible side extrusions on all sign edges. Prepare surfaces of extr usions composing the sign face to receive retroreflective background material according to the extrusion and retroreflective material manufacturers’ recommendations. Provide all remaining surfaces of extrusions and side extrusions with a soft matte finish.
833.01.02 Sheeting Signs. Conform to ASTM B 209, Alloy 6061-T6 or 5052-H38.
Fabricate signs of the size and shape specified. Provide a thickness of 125 mils if any single edge dimension of the sign exceeds 3 feet. If no single edge dimension exceeds 3 feet, provide a thickness of 80 mils. Prepare the side of the sheet to be used as the sign face to receive retroreflective background material according to the sheeting and retroreflective material manufacturer’s recommendations. 833-1
Source: Kentucky Standard Specifications for Road and Bridge Construction, 2019 Edition. Pages 629–631 of 718.