Aggregate & Concrete Testing Services

Bridge building contractors and concrete pavement contractors who work under ODOT Item 455 (Item 455) are required to use the services of a "certified laboratory"  to test raw materials and produce a concrete mix design which meets the requirements of ODOT Item 499 (Item 499).  The certified laboratory also tests the plastic concrete as it is placed in the structure or roadway as part of the contractor's quality control (QC) and acceptance testing. As a check, ODOT also tests the plastic concrete, although at a reduced frequency.  Finally, the certified laboratory tests the hardened concrete for acceptance and final payment, with ODOT also performing some companion testing for quality assurance.