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r""'I . II . 346-8 Plastic Concrete Sampling and Testing. QC tests will include air content, temperature, slump, compressive strength cylinders, and may include plastic unit weight. In addition, calculate the water to cementitious materials ratio for compliance to the approved mix design. Ensure that each truck has a valid inspection card issued by the Department, the revolution counter on the mixer is working properly, and calibration of the water dispenser has been performed within the last twelve months and verify batch weights within required limits of the mix design. Perform plastic concrete tests on the initial delivery of each concrete design mix each day. Ensure QC technicians meeting the requirements of Section 105 are present and performing tests throughout the placement operation. Ensure one technician is present and performing tests throughout the placement operation at each placement site. If a placement site has multiple concrete trucks, identify the number of technicians in the Quality Control Plan. If a placement site has multiple trucks placing concrete, then have at least two technicians present at that site. Ensure all equipment utilized meets this Specification. Do not proceed with the placement operation until the delivered concrete complies with plastic properties specified. After placement begins, perform QC tests to ensure compliance with Specification requirements on each LOT of concrete. Reject non- complying loads which cannot be adjusted at the jobsite. Ensure that corrections are made on subsequent loads. Furnish sufficient concrete of each design mix as required by the Engineer for verification testing. When the Engineer's verification tests results do not compare with the QC plastic properties test results, within the limits defined by the Independent Assurance (IA) checklist comparison criteria, disposition of the concrete will be at the option of the Contractor. If a QC test fails, reject the remainder of that load, terminate the LOT, and notify the Engineer. Make cylinders representing that LOT from the same sample of concrete. Following termination of a LOT, re-initiate initial plastic properties tests until such time as the water to cementitious materials ratio, air content, temperature and slump comply with the Specification requirements. Initiate a new LOT once the testing indicates compliance with Specification requirements. When three consecutive LOTs, or when five LOTs in two days of production of the same design mix are outside the specified tolerances, suspend production. Make the necessary revisions to concrete operations and increase the frequency of QC testing in the QCP to bring the concrete within allowable tolerances. Obtain the Engineer's approval of the revisions before resuming production. After production resumes, obtain the Engineer's approval before returning to the normal frequency of QC testing. If concrete placement stops for more than 90 minutes, perform initial plastic properties testing on the next batch and continue the LOT. Cylinders cast for that LOT will represent the entire LOT. The Department may perform Independent Verification testing at any time to evaluate the QC of the concrete. The comparison between the Independent Verification testing and the QC testing is identified in the IA Checklist Criteria. When a test does not compare, the Contractor will revise the QCP as deemed necessary by the Engineer. The Department reserves the right to notify the IA to review the testing procedures and equipment. ., . ...., . , . II . n I ,.., . I " . r'1 . ,.., . I I . r"""l . r"""l . ,.., . r'1 . .., . r- I 09/09 01000-102 03-4122.F -