Abstract: A reusable apparatus for forming in situ concrete test specimens comprises a flexible open outer container and a series of smaller closable cylinders for placement within the larger container. The assembly is placed within a depression formed in the wet concrete when the slab is poured, with outer and inner containers being filled with representative concrete of the slab. The assembly is left for the concrete to cure, with smaller containers removed from the larger container after curing. Apparatus is included for facilitating lifting the sample from the slab, after curing. The larger portion of surrounding concrete is then broken away to access the smaller cylinders, which may be shipped to a testing facility where the inexpensive containers are removed to expose the test specimens. The larger outer container may be flexed to remove it from the depression, and the depression filled with fresh concrete to repair the test site.