This test method allows testing of drilled cores and cast specimens. When testing drilled cores from a structure, it is of interest to test the outer layer to include the impact of curing on the test result. However, when testing cast cylinders that are moist cured in the laboratory for the purposes of evaluating the apparent diffusion coefficient of a concrete mixture, testing the top surface is not equivalent to testing the quality of the cover thickness in a structure. The purpose of testing cast specimens is typically to evaluate the quality of concrete and verify whether the concrete supplied meets the specification criterion. Results for the top 50 mm slice will likely be more variable, especially for concrete mixtures that exhibit tendencies for bleeding and segregation and will also be affected by how the specimen surface is struck off. These may differ from that observed in the field where the concrete workability, placement and finishing practices are different. To address this concern, this revision is to test slices cut from the center of the length of cast cylinders.
Developed by Subcommittee: C09.66
Staff Manager: W Scott Orthey
Date Initiated: 01-08-2020
Technical Contact: R. Doug Hooton