Specifications Vol. II - Laserfiche WebLink

Home Browse Search

r"1 . , . ., . 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. 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. Have the accuracy of admixture measuring dispensers certified annually by the admixture supplier. When Volumetric Mixers are used, deliver concrete in accordance with the requirements of Volumetric Mixer Manufactures Bureau (VMMB) and ensure that the vehicle has a VMMB registered rating plate. 347-3.2 Mixers: Ensure that mixers are capable of combining the components of concrete into a thoroughly mixed and uniform mass, free from balls or lumps of cementitious materials, and capable of discharging the concrete uniformly. Operate concrete mixers at speeds per the manufacturer's design. Do not exceed the manufacturer's rated capacity for the volume of mixed concrete in the mixer, mixing drum, or container. 347-3.3 Delivery: The maximum allowable mixing and agitation time of concrete is 120 minutes. 347-3.4 Small Quantities of Concrete: With approval of the District Materials Engineer, small quantities of concrete, less than 3 yd3 placed in one day and less than 0.5 yd3 placed in a single placement may be accepted using a pre-bagged mixture. The Engineer will verify that the pre-bagged mixture is prepared in accordance with the manufactures recommendations and will meet the requirements of this Specification. ..., . ,., . ,.., . II . .., . ,., . ., . ,..., 347-4 Control of Quality. 347-4.1 Concrete Mix Design: Before producing any concrete, submit the proposed mix design to the Engineer on a form provided by the Department. 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 the Department concrete delivery ticket. The Engineer may disqualify any concrete production facility for non-compliance with Specification requirements. 347-4.2 Sampling and Testing: The Engineer may sample and test the concrete at their discretion to verify its quality. The minimum 28-day compressive strength requirement for this concrete is 2,500 psi. 347-4.3 Records: Maintain the following records for review for at least three years after final acceptance of the project: 1. Approved concrete mix designs. 2. Materials source (delivery tickets, certifications, certified mill test reports). 3. A copy of the scale company or testing agency report showing the observed deviations from quantities checked during calibration of the scales and meters. 4. A copy of the documentation certifying the admixture weighing/measuring .., . . r1 . ,.., . ..., . II . .., . devices. 1"'"1 5. Recent NRMCA, VMMB or Department inspection records certifying the plant or truck can produce concrete and documentation showing that action has been taken to correct deficiencies noted during the inspections. . r"'1 09/09 01 000-11 0 03-4122.F -