833All fabricators of precast reinforced concrete box culverts shall maintain an adequate level

833 All fabricators of precast reinforced concrete box culverts shall maintain an adequate level of quality control. Plan t certification by NPCA (National Precast Concrete Association), ACPA (American Concrete Pipe Association) plant certification for box culverts, or other approved equal certification program will be required to verify this level of quality control. Plant approval must be obtained prior to the start of fabrication. All Fabricators shall then submit evidence of Plant approval to the MCS&T Division on an annual basis. All box culverts shall be cured in accordance with section 601.12 or 603.8 except that curing may be discontinued once 70% of the design strength is achieved. All box culverts shall meet design strength prior to shipment. 714.7.1 -Trial Fitting: For box culverts, trial fitting of adjacent pieces, prior to shipping, will be required as p art of the final inspection process, at a minimum of twenty -five percent (25%) of the project total. Adjacent box culverts will either be stacked in pairs vertically or placed horizontally as to be installed. The gaps between each pair will be measured, and dunnage will be placed below the culvert(s) to prevent damage. The maximum gap between the adjacent pieces shall not exceed ½ inch, unless otherwise stated in the construction plans. 714.7.2 -Price Adjustments: Box culverts not achieving the 28 da y shipping strength, but for which evaluation indicates may still be used, will be paid for at a reduced price in accordance with the following formulas, depending on who purchased the box culverts: Formula 1: Use the following price reduction formula w hen the box culverts are used in a project constructed by the Contractor: Price Reduction =    − '_ ' 5.0cc fXf x 40% of the Contract Unit Bid Price Formula 2: Use the following price reduction formula when the box culverts are used in a project constructed by the Division: Price Reduction =    − '_ ' 5.0cc fXf x IC Where: ' cf = 28-Day Compressive Strength, psi (MPa) _ X = Average 28 -Day Compressive Strength as determined by a minimum of 2 compressive strength test cylinders fabricated from a batch of concrete as it was placed in the forms for the box culverts IC (Formula 2 only) = The invoiced cost of the box culvert it self, as billed to the Division by the Fabricator. This cost shall not include other items associated with the box culverts such as a gaskets or etc. 714.8 -CONCRETE SAFETY SLOPE END SECTIONS : Precast concrete safety slope end sections shall conform to the requirements of the cited Specifications for the pipe to the extent to which they apply and to the details shown on Standard Detail Drawing DR 4. 714.9 through 714.16: Blank