3011
4598.004
Mather, Bryant
Concrete International
Article
American Concrete Institute
Jan 2001
46-47
In a letter in the September 2000 issue of Concrete International, D. Srinivasan asked, “Will there be a self-curing concrete?” My answer to this is strongly affirmative for three reasons. First, most of the concrete that is produced and placed each year all over the world already does self-cure. Some of it wasn’t intended to have anything done to its exterior surface. But finishing did in fact take place, and yet the concrete’s ability to serve its intended purpose had not been significantly reduced.
It was this fact that prompted Russell Fling, when he became ACI President, to ask the Technical Activities Committee (TAC) to re-establish the Institute’s Curing Committee. The charge to the committee arose from President Fling’s experience that a lot of the concrete with which he was concerned received no treatment under the label of “curing”, yet seemed to be no worse for that having been the case. I was given the job of chairing that committee. The committee’s report stated in its Section 1.2.
“Curing is the maintaining of a satisfactory moisture content and temperature in concrete during its early stage so that desired properties may develop. Curing is essential in the production of concrete that will have the desired properties. The strength and durability of concrete will be fully developed only if it is cured. No action to this end is required, however, when ambient conditions of moisture, humidity, and temperature are sufficiently favorable to curing. Otherwise, specified curing measure shall start as soon as required”.
Second, most of the concrete in the world is placed in quantities that are of sufficient thickness such that most of the material will remain in satisfactory conditions of temperature and moisture during its early stages. This is so regardless of what steps are taken, or not taken, to ensure that such conditions are maintained in the exterior layer.