Cast-in-place punch out cores are the newest way to install, remove and test concrete cores within the actual structures. These cores are said to be as accurate as drilled cores. The method employs a patented device made of two plastic components identified as "inner member" and "outer member." The total device is installed in the structural element, such as a concrete slab, before the concrete is placed simply by nailing the unit to the slab form such as is done with a pipe sleeve. The finishing operation takes place unhampered by the device as it does not project above the surface of the concrete. The outer member attaches itself to the slab and the inner member has a continuous top flange of stopper to prevent the concrete from entering the air space between the two members. The outer member remains in the slab and can be used as a pipe sleeve or filled with concrete. The inner member is then cut open, yielding a representative test core of the in-place concrete. The core is then capped and tested. A detailed report is issued to the client covering such information as compressive strength, concrete age, curing, and protection of the element from which the cores were taken. The number of cores to be used in a slab is based upon square footage of cast area and not upon cubic yards of concrete placed.