Title:
Specified Tolerances versus As-Built Data
Author(s):
Bruce A. Suprenant
Publication:
Concrete International
Volume:
24
Issue:
5
Appears on pages(s):
49-52
Keywords:
DOI:
Date:
5/1/2002
Abstract:
There isn’t a lot of published data showing the as-built versus design dimensions of concrete members. Variations from design dimensions are caused by deviations from the specified values of the cross-sectional shape, the position of the reinforcing bars, the vertical and horizontal alignment of the forms, and the grades and surface profiles of the constructed structure. Variations arise during different phases of the construction process. Variations in size and shape are mainly dependent on forming equipment and methods, and to some extent on the concrete placement and consolidation methods. Contractors and testing laboratories often measure the as-built geometry of structures, but the information is rarely collected or reported. As-built data that has been collected, however, can be used to evaluate the degree to which ACI’s specified tolerances are reasonably attainable.