The box culvert shall be constructed in accordance with ASTM Standard C1577-20, 0 to 2 feet fill, HL-93 Design Tandem live load conditions and Section 302 of 2020 VDOT Road and Bridge Specifications with following additions and/or exceptions: a. Clear concrete cover over the reinforcing steel: 1.Top Slab-Top Reinforcement 2 1/2" (+3/8", -0") 2.Top Slab-Bottom Reinforcement 2" (+3/8", -0") 3. All other reinforcement 1 1/2" (+3/8", -0") b. Distribution reinforcement shall be provided in top slab, bottom slab and both walls. Spacing center to center of all reinforcement shall not be more than 8". c. The requirement for joint shear transfer capability to be waived. d. 2 1/2" diameter holes in top slab shall be provided for lifting sections. Details and locations of lift holes shall be shown on shop drawings. e. 2" diameter holes in walls shall be provided for pulling sections. Details and locations of pull holes shall be shown on shop drawings. f. Any holes for lifting, pulling, etc. shall be wet cast or core drilled after concrete has been cured. g. Concrete shall be a minimum of Class A5 (5,000 psi design strength) according to Section 217, Table II-17, of VDOT Specifications except air content shall be 5 ½% ±1 ½%. h. Ends shall be standard male and female on all sections. i. The reinforcing steel shall be Low-carbon, Chromium reinforcing steel and shall conform to the requirements of ASTM A1035/A1035M – Standard Specification for Deformed and Plain, Low-carbon, Chromium, Steel Bars for Concrete Reinforcement and shall conform to the requirements of Section 223 of the Specifications. The reinforcing steel shall be deformed and have a minimum yield stress of 100,000 psi. j. If sections are manufactured using a slip-formed dry-pack method of manufacture, any modifications to walls or slabs to produce a nonstandard section such as the end sections shall be accomplished by wet casting concrete a minimum of 6” in depth from the exposed surfaces.
