Researchers evaluating the American Concrete Institute’s Guide to Formed Concrete Surfaces (ACI 347.3R-13) contend that a) suggested measurements or other criteria used in assigning a given formed surface to one of the document’s four categories is neither objective nor practical; b) converting ACI 347.3R-13 recommendations to specification requirements could result in disputes and litigation; and, c) preparation of concrete mockups for architect or engineer approval is superior to guide methodologies.
|Concrete Industry Management students mapped the Surface Void Ratio on an as-cast wall in metro New York. A measure of the air void size and quantity, SVR is one factor in the four ACI 347 categories. PHOTO: Janet Greco Stanton, Ruttura & Sons Construction Co.|
ACI 347.3R-13 surface categories range from basic (areas with limited importance of formed surface quality) to special requirements (areas with formed surface quality of high importance). Research aimed at providing architects and engineers an alternative means of specifying cast-in-place concrete surface quality was led by the American Society for Concrete Contractors with additional RMC Research & Education Foundation and ACI Foundation participation. Library, laboratory and field research activities were conducted in cooperation with Concrete Industry Management (CIM) programs at Middle Tennessee State University, Murfreesboro; California State University, Chico; New Jersey Institute of Technology; and, Texas State University.
An ASCC report on the research includes other recommendations for ACI Committee 347 on Formwork to consider when revising 347.3R-13. Co-authored by ASCC Concrete Construction Specialist Dr. Ward Malisch and MTSU CIM Department Head Dr. Heather Brown, the report is available as a free download at www.ascconline.org.