7-100 SECTION 728 – ROADSIDE SAFETY BARRIER MATERIALS
728.01 Posts .
a.Wood Posts . Posts shall be straight, sound wood meeting one of the following:
1.Red (Norway) Pine . No. 1 Stress Grade red (Norway) pine as determined in accordance with the Northeastern Lumber Manufacturers Association; or
2.Southern Pine . No. 2 Stress Grade southern pine as determined in accordance with the Southern Pine Inspection Bur eau. Wood posts shall be treated in accordance with Subsection 726.01 for sawn guardrail posts after fabrication. Inspection, quality control, handling, storage, field fabrication, and field treatment shall be in accordance with AWPA Standard M2 , AWPA Standard M3 , and AWPA Standard M4 .
b.Steel Posts and End Post Caps . Posts and caps shall be structural steel in acco rdance with AASHTO M 270 , Grade 36. Posts shall be galvanized in accordance with AASHTO M 111 after fabrication.
728.02 Beam and Cable Elements .
a.Cable . Cable shall be wire rope in accordance with AASHTO M 30 , Type I, Class A Coating.
b.W-Beam and Thrie Beam . Beam shall be corrugated sheet steel W -beam in accordance with AASHTO M 180 , Type II.
1.Standard Beam . Standard beam shall be Class A in accordance with AASHTO M 180 .
2.Heavy Duty Beam . Heavy duty beam shall be Class B in accordance with AASHTO M 180 .
c.Box Beam . Beam shall be square steel structural tubing in accordance with Subsection 714.11 . Beams shall be galvanized in accordance with AASHTO M 111 after fabrication.
d.Steel -Backed Timber Beam .
1.Timber . Timber shall have a minimum allowable bending stress of 1,450 psi.
2.Steel Backing and Splice Plates . Steel backing and splice plates shall be in accordance with AASHTO M 270 , Grade 50. Steel backing and splice plates shall be galvanized in accordance with AASHTO M 111 after fabric ation.
e.End Sections . End sections shall be sheet steel in accordance with AASHTO M 180 , Type II. 7-101 728.03 HARDWARE .
a.Cable, W -Beam, and Thrie Beam Guardrail Hardware . Hardware shall be galvanized in accordance with AASHTO M 232 .
1.Cable -Beam Connectors .
a.Bolts . Bolts shall be in accordance with ASTM A307 , Grade A.
b.Washers . Washers shall be in accordance with ASTM F436 and ASTM F844 .
c.Nuts . Nuts shall be in accordance with ASTM A563 .
2.Cable Fittings . Anchor angles, cable end assemblies, and splices shall be in accordance with AASHTO M 30 .
b.Box Beam Guardrail Hardware .
1.Splice Plates and Brackets . Splice plates and brackets shall be structural steel in accordance with AASHTO M 270 , Grade 36. Splice plates and brackets shall be galvanized in accordance with AASHTO M 111 after fabrication.
2.Post-Bracket -Beam Connectors . Post -bracket -beam connecto rs shall be galvanized in accordance with AASHTO M 232 .
a.Bolts . Bolts shall be in accordance with ASTM A307 , Grade A.
b.Washers . Washers shall be in accordance with ASTM F436 .
c.Nuts . Nuts shall be in accordance with ASTM A563 .
3.Rail-Splice Connecto rs. Bolts, washers, and nuts shall be in accordance with Subsection
714.05 , except that rotational capacity, proof load, and wedge tests will not be required.
c.Steel -Backed Timber Guardrail Hardware . Hardware shall be galvanized in accordance with AASHTO M 232 .
1.Bolts and Lag Screws . Bolts and lag screws shall be in accordance with ASTM A307 , Grade A.
2.Washers . Washers shall be in accordance with ASTM F844 .
3.Nuts . Nuts shall be in accordance with ASTM A563 . 7-102 728.04 OFFSET BLOCKS .
a.Composite Offset Blocks . Composite o ffset blocks shall have an FHWA eligibility letter and shall be one of the products on the Agency’s Approved Products List .
b.Wood Offset Blocks . Wood o ffset blocks shall be in accordance with Subsection 728.01(a) .
728.05 CONCRETE ANCHORS . Concrete anchors may be precast or cast -in-place in accordance with
the Contract requirements for the respective anchor.
a.Concrete . Concrete shall hav e a minimum 28 -day compressive strength of 4,000 psi as determined in accordance with AASHTO T 22 . Concrete shall be cured in accordance with AASHTO M 199 for sufficient time to develop the minimum 28 -day compressive strength.
b.Bar Reinforcement . Bar reinforcement shall be in accordance with Subsection 713.01 .
728.06 MANUFACTURED TERMINAL SECTIONS . Manufactured terminal sections (MTS) shall
have an FHWA eligibility letter demonstrating the respective MASH test level, be one of the p roducts on the Agency’s Approved Products List , and meet the following requirements :
a.W-Beam . MTS shall be compatible with w -beam guardrail and meet the following requirements:
1.Flared . Flared MTS shall gradually increase the offset from the edge of pavement from the end of the guardrail installation to the end of the MTS installation.
a.TL-2. MTS TL -2 shall be a minimum of Test Level 2 in accordance with MASH .
b.TL-3. MTS TL -3 shall be a minimum of Test Level 3 in accordance with MASH .
2.Tange nt. Tangent MTS shall maintain a consistent offset from the edge of pavement from the end of the guardrail installation to the end of the MTS installation.
a.TL-2. MTS TL -2 shall be a minimum of Test Level 2 in accordance with MASH .
b.TL-3. MTS TL -3 shall be a minimum of Test Level 3 in accordance with MASH .
b.Box Beam . Box beam MTS shall be compatible with box beam guardrail and meet the following requirements: 7-103 (1) Flared . Flared MTS shall gradually increase the offset from the edge o f pavement from the end of the guardrail installation to the end of the MTS installation.
a.TL-2. MTS TL -2 shall be a minimum of Test Level 2 in accordance with MASH .
b.TL-3. MTS TL -3 shall be a minimum of Test Level 3 in accordance with MASH .
2.Tange nt. Tangent MTS shall maintain a consistent offset from the edge of pavement from the end of the guardrail installation to the end of the MTS installation.
a.TL-2. MTS TL -2 shall be a minimum of Test Level 2 in accordance with MASH .
b.TL-3. MTS TL -3 shal l be a minimum of Test Level 3 in accordance with MASH .
728.07 ENERGY ABSORPTION ATTENUATORS . Energy absorption attenuators shall have an
FHWA eligibility letter demonstrating the respective MASH test level, be one of the products on the Agency’s Approved Products List , and meet the following requirements :
a.Type I . Type I attenuators shall be temporary and meet the following requirements:
1.TL-2. TL-2 attenuators shall be a minimum of Test Level 2 in accordance with MASH .
2.TL-3. TL-3 attenuators shall be a minimum of Test Level 3 in accordance with MASH .
b.Type II . Type II attenuators shall be permanent and meet the following requirements:
1.TL-2. TL-2 attenuators shall be a minimum of Test Level 2 in accordance with MASH .
2.TL-3. TL-3 attenuators shall be a minimum of Test Level 3 in accordance with MASH .
728.08 TEMPORARY TRAFFIC BARRIER . Temporary Traffic barrier, and corresponding connections,
shall be Test Level 3 longitudinal barrier with a corresponding FHWA eligibil ity letter demonstrating the test level. Test level criteria shall be in accordance with Table 728.08A . TABLE 728.08A – TEMPORARY TRAFFIC BARRIER TEST LEVEL CRITERIA Date of Manufacture Test Level Criteria Prior to January 1, 2020 NCHRP Report 350 or MASH January 1, 2020 or later MASH 7-104 SECTIO N 729 – CURB MATERIALS 729.0 1 VERTICA L GRANIT E CURB . Vertical granite curb shall consist of hard, durable, quarried granite. It shall be gray in color, free from seams, cracks, or other structural defects, and shall be of a smooth splitting character. The curb may contain natural color variations that are characteristic of the granite source. Granite curb shall meet the requirements of ASTM C615 .
a.Source . The Contractor shall submit for approval the name of the quarry that is the proposed source of the granite for curb materials. Such submission shall be made sufficiently in advance of ordering so that the Engineer may have an opportunity to judge the stone, both as to quality and appearance. Samples of curbing shall be submitted for approval only when requested by the Engineer.
b.Finish and Surface Dim ensions . The individual curb stones shall be of the dimensions shown on the Plans and shall be of uniform thickness in any continuous run. The individual curb stones shall be furnished in minimum lengths of 6 feet. The top surface of the curb stones shall be sawed to an approximately true plane and shall have no projection or depression greater than 1/8 inch. The bottom surface may be sawn or split. The top front arris line shall be rounded to a 1/2 inch radius as shown in the Contract. The exposed arris li nes shall be pitched straight and true, with no variations from a straight line greater than 1/8 inch. The front face shall be at right angles to the plane of the top and shall be smooth quarry split or sawn for the full depth. Drill holes in the exposed p art of the face shall not be permitted. The front face shall have no projections greater than 1 inch or depressions greater than 1/2 inch, measured from the vertical plane of the face through the top arris line for 8 inches down from the top. For the remai ning distance, there shall be no projections or depressions greater than 1 inch measured in the same manner. The back surface of the curb stones shall have no projection for 3 inches down from the top which would fall outside of a plane having a batter of 3:1 (V:H) from the back arris line. The ends of all curb stones shall be square with the planes of the top and front face, and so finished that when the stones are placed end to end as closely as possible, no space more than 1 inch shall show in the joint for the full width of the top or down on the face for 8 inches. The remainder of the end may break back a maximum of 6 inches from the plane of the joint. Curbing stones to be set on a radius of 80 feet or less shall be cut to the curve required, and their ends shall be cut on radial lines.
Source: Vermont Standard Specifications for Construction, 2024 Edition. Pages 1252–1255 of 1,380.