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344-3 Production, Mixing and Delivery of Concrete. 344-3.1 Concrete Production Requirements: Use concrete production facilities certified by the National Ready -Mixed Concrete Association (NRMCA), approved by the FDOT. Produce concrete utilizing equipment that is in good operating condition and operated in a manner to ensure a consistent product. When moisture probes are not used, ensure that the concrete production facility determines the free moisture for the coarse and fine aggregates within two hours prior to each day's batching. On concrete placements expected to exceed three hours, perform an additional moisture test approximately half way through the batching operations and adjust batch proportions accordingly. Ensure that the calibration of the measuring devices of the concrete production facilities meets the requirements of Chapter 531 of the Florida Statutes, and are in accordance with Chapter 9.2 of the FDOT Materials Manual. At least quarterly, ensure that all scales, meters and other weighing or measuring devices are checked for accuracy by a qualified representative of a scale company registered with the Bureau of Weights and Measures of the Florida Department of Agriculture. As an alternative, the producer may have this frequency identified in an FDOT approved QC plan. The accuracy of admixture measuring dispensers will be certified annually by the admixture supplier. When Volumetric Mixers are used for Category I applications, deliver concrete in accordance with the requirements of Volumetric Mixer Manufacturers Bureau (VMMB) and ensure that the vehicle has a VMMB registered rating plate. 344-3.2 Classes of Concrete: Classes of concrete to be used on the project will be defined in the Contract Documents. 344-3.3 Contractors Quality Control: The Contractor will supply a Quality Control (QC) plan to identity to the Agency how quality will be ensured at the project site. During random inspections the Agency will use this document to verify that the construction of the project is in agreement with his QC plan. 344-3.4 Concrete Mix Design: Before producing any concrete, submit the proposed mix design to the Engineer on a form provided by the Agency. Otherwise, the agency will accept mix designs previously described in an FDOT approved QC plan. In any event, use only concrete mix designs having prior approval of the Engineer. Materials may be adjusted provided that the theoretical yield requirement of the approved mix design is met. Show all required original approved design mix data and batch adjustments and substituted material on an Agency approved concrete delivery ticket. The Engineer may disqualify any concrete production facility for non-compliance with specification requirements. 344-3.5 Delivery: For cast -in-place applications, the maximum allowable mixing and agitation time of concrete is 90 minutes. Furnish a delivery ticket on a form approved by the Agency with each batch of concrete before unloading at the placement site. The delivery ticket shall be printed. Record material quantities incorporated into the mix on the delivery ticket. Ensure that the Batcher responsible for producing the concrete certifies that the batch was produced in accordance with these Specifications and signs the delivery ticket. The Contractor shall sign the delivery ticket certifying that the concrete was batched, delivered and placed in accordance with these Specifications. The Contractor shall be responsible for rejecting loads of concrete that do not meet the plastic properties of the approve mix design or the minimum compressive strength requirements. 01025-33 Technical Specifications FAPublic Works\ENGINEERING DIVISION PROJECTS\0455-8th Street Sidewalk Improvements 18th Ct to Old Dixie\Admim\bid documents\Technical Specifications.doc