****THIS IS A NEW IM. – PLEASE READ CAREFULLY.****
SAFETY GRATES FOR CONCRETE BOX CULVERS
GENERAL
Safety
grates are designed to provide a suitable safety guard for the exposed end of
the box culverts.
REQUIREMENTS FOR SAFETY GRATES
- Safety grates
must comply with the requirements of the
Design Standard RF -29.
- Safety grates
shall be constructed from the original construction plans.
- Thru
dimensions shall be verified at the site before fabrication of the
components.
- Shop drawings
shall be required and must be submitted for approval prior to fabrication.
- Proper fitting
of the safety grates into the headwall opening shall be the responsibility
of the contractor.
- Pipes for the
safety grates shall be schedule 40 meeting the requirements of ASTM A 53
Grade B and the requirements of
Article 4153.05
- Bolts shall
meet the requirement of ASTM A 307, Class A with full body diameter with
hexagonal head. Threads shall meet the requirements of ANSI B1.1, united
coarse thread series Class 1A and Class 1B fit.
- Nuts shall
meet the requirements of ASTM A 563, Grade DH or DH3, and shall comply
with the requirements of Article 4153.06
- Plain washers
meeting the requirements of ASTM F 436 and / or the requirements of ASME B
18.22.1, Type A or B plain washers.
- Galvanizing of
all threaded components shall be in accordance with the requirement sof
ASTM F 2329and / or B 695 Class 55. Threaded components (bolts and uts)
shall be coated by the same zinc coating process and the galvanizer’s
option is limited to one process with no mixed processes.
- Galvanizing of
all other items (bars, brackets, and strips) shall be in accordance with
the requirements of ASTM A 123
APPROVAL
Acceptance
of safety grates shall be based on approved shop drawings and approved
fabricators. Approved fabricators are listed in Appendix A of this IM.