Title: Is Delamination Really a Mystery?
Author(s): Carl Bimel
Publication: Concrete International
Appears on pages(s): 29-34
Keywords: air-entrained concretes; delaminating; floors; surface finishing;
A task force was created by ACI Committee 302, Construction of Concrete Floors. This task force was made up of members of the concrete construction industry, ACI members, equipment manufacturers, and university staff. The express purpose of the fact-finding program was to attempt to determine if the use of float pans -- in any way or at any time during the finishing process -- is responsible for or contributes to concrete delamination. At the same time, the task force planned to document the effect of a smooth, dense, hard-troweled finish on air-entrained concrete. Four concrete panels (slabs) were placed using the same concrete mix, with the exception of one panel which contained air. The panels were then finished with different techniques, with the only variable being the time at which float pans began the finishing operation. Results are assessed by an ACI Committee 302 member with over 35 years of experience in concrete construction.