SS407-002020-02.docx
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- Attached to
- Construction, University Drive Bike Lanes
- Solicitation number
- IFB-114424
- Issued by
- Fairfax County, Virginia
About this file
This is a supplemental specifications document issued by the Virginia Department of Transportation (VDOT) dated November 1, 2022, establishing guidelines for steel and other metal structures on all transportation projects. The document amends Section 407 of the 2020 Road and Bridge Specifications to establish detailed requirements for fabrication procedures, structural connections using high-strength bolts, and finishing processes. Key requirements include mandatory mill analysis documentation for all steel heats prior to fabrication, ASTM A6 color code identification marking for steel pieces, and specific protocols for transferring directional markings during cutting operations. Field connections must utilize 7/8-inch diameter high-strength bolts fabricated to ASTM F3125, Grade A325 unless otherwise specified, with consideration given to welded connection substitutions upon written contractor request. The specification establishes that bolts, nuts, and washers must originate from a single manufacturer per structure and must come from the same rotational-capacity lot, with mandatory field rotational-capacity testing required on two nut-bolt-washer assemblies for each diameter and length combination prior to installation.
The document provides detailed installation and tensioning requirements, specifying that Grade A490 bolts and galvanized Grade A325 bolts cannot be reused, while other bolts may be reused only with engineer approval. Minimum bolt tension is established at 70 percent of the specified minimum tensile strength, with snug-tight tightening progressing systematically from rigid connection areas to free edges. Direct tension indicator washers are required for all high-strength bolts, with specific placement and substitution guidelines provided relative to hardened washers. A comprehensive bolt tension table establishes minimum required tensions for bolt sizes ranging from 1/2 inch to 1 1/2 inch, with separate requirements for Grade A325 and Grade A490 bolts. The specification also addresses weathering steel finishing requirements, mandating cleaning and coating of designated painted areas in accordance with Section 411 standards.
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Guidelines -For use on all projects.
SS407-002020-02 November 1, 2022
VIRGINIA DEPARTMENT OF TRANSPORTATION
2020 ROAD AND BRIDGE SUPPLEMENTAL SPECIFICATIONS
SECTION 407 – STEEL AND OTHER METAL STRUCTURES
SECTION 407 – STEEL AND OTHER METAL STRUCTURES of the Specifications is amended as follows:
Section 407.04 – Fabrication Procedures is amended by replacing the seventh, eighth, and ninth paragraphs with the following:
The Contractor shall furnish a complete mill analysis showing chemical and physical results from each heat of steel for all units prior to fabrication. Before cutting, pieces of steel other than steel conforming to ASTM A709, Grade 36, that are to be cut to smaller-sized pieces shall be legibly marked with the ASTM A6 specification identification color code or the material specification designation. The identification color code of the latest system adopted under ASTM A6 shall be used to identify material. Any markings that indicate direction of roll shall be transferred to each new piece before cutting the new piece from the larger plate.
If requested by the Engineer, the Contractor shall furnish an affidavit from the fabricator certifying that the fabricator has marked and maintained the identification of steel in accordance with these specifications throughout the fabrication operation.
Section 407.06(c) – Assembly of Structural Connections Using High-Strength Bolts is amended by replacing the first paragraph with the following:
Assembly of Structural Connections Using High-Strength Bolts: Field connections shall be made with high-strength bolts 7/8-inch in diameter fabricated in accordance with ASTM F3125, Grade A325 unless otherwise specified. The Engineer will give consideration to the substitution of adequately designed welded connections if requested in writing by the Contractor.
Section 407.06(c)1 – Bolts, nuts, and washers is replaced with the following:
Bolts, nuts, and washers: Bolts, nuts, and washers shall conform to Section 226 and shall each be from one manufacturer on any one structure unless otherwise approved by the Engineer. In addition, each bolt, nut, and washer combination, when installed, shall be from the same rotational-capacity lot. Prior to installation, the Contractor shall perform a field rotational-capacity test on two nut, bolt, and washer assemblies for each diameter and length in accordance with VTM 135. Bolts fabricated in accordance with ASTM F3125, Grade A490 and galvanized bolts fabricated in accordance with ASTM F3125, Grade A325 shall not be reused. Retightening previously tightened bolts, which may have been loosened by the tightening of adjacent bolts, shall not be considered a reuse. Other bolts may be reused only if approved by the Engineer. Threads of plain (uncoated) bolts shall be oily to the touch when installed. Galvanized nuts shall be lubricated by lubricant containing a visible dye. Threads of weathered or rusted bolts shall be cleaned of loose rust, scale, and debris and relubricated. Lubricant shall be as recommended by the fastener manufacturer.
Section 407.06(c)3 – Installation is amended by replacing the second paragraph with the following:
When bolts fabricated in accordance with ASTM F3125, Grade A490 are used with steel having yield points less than 40 kips per square inch, hardened washers shall be installed under the nut and bolt head.
Section 407.06(c)3 – Installation is amended by replacing the eighth paragraph with the following:
The required minimum bolt tension is equal to 70% of specified minimum tensile strengths of bolts rounded to the nearest kip as specified in ASTM F3125 for Grades A325 and A490. Snug tight is defined as the tightness attained when a power wrench begins to impact solidly or when the bolts are firmly hand tightened with a spud wrench such that the complete area of the connecting surfaces are brought into firm contact with each other. Snug tightening shall progress systematically from the most rigid part of the connection to the free edges, and then the bolts of the connection shall be retightened in a similar systematic manner as necessary until all bolts are simultaneously snug tight and the connection is fully compacted.
Section 407.06(c)3b – Direct Tension Indicators (DTI) is amended by replacing the first paragraph with the following:
Direct Tension Indicators (DTI): Direct tension indicator washers shall be used for all high strength bolts, and installation shall be in accordance with Section 407.06(c)3; however, the indicator washer shall not be considered a substitute for the required hardened washer under the turned element. The indicator washer may be considered a substitute for the hardened washer required under the unturned element when bolts conforming to ASTM F3125, Grade A490 are used with steel conforming to ASTM A709, Grade 36. Direct tension-indicator washers shall not be painted or coated with any epoxy or similar material prior to installation. The normal installation shall consist of the load indicator washer being placed under the unturned bolt head or unturned nut. However, if conditions require installation under the turned bolt portion, a hardened flat washer or nut face washer shall be fitted against the tension-indicating protrusions. Tension-indicating washers shall not be substituted for the hardened washers required with short-slotted or oversized holes but may be used in conjunction with them.
Table IV-3 – Bolt Tension is replaced with the following:
TABLE IV-3
Bolt Tension
| Bolt Size |
| Required Min. Bolt Tension (lb.) |
| Grade A325 Bolts |
| Grade A490 Bolts |
| 1/2 |
| 12,000 |
| 15,000 |
| 5/8 |
| 19,000 |
| 24,000 |
| 3/4 |
| 28,000 |
| 35,000 |
| 7/8 |
| 39,000 |
| 49,000 |
| 1 |
| 51,000 |
| 64,000 |
| 1 1/8 |
| 56,000 |
| 80,000 |
| 1 1/4 |
| 71,000 |
| 102,000 |
| 1 3/8 |
| 85,000 |
| 121,000 |
| 1 1/2 |
| 103,000 |
| 148,000 |
Section 407.06(i) – Finishing is amended by replacing the third paragraph with the following:
Areas of weathering steel that are designated to be painted shall be cleaned and coated in accordance with Section 411.
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