ACI 363.2R

Description / Abstract: This guide discusses QC and testing practices of HSC. HSC usually is associated with structures that have been optimized for performance. Therefore, a high degree of confidence in concrete quality should be achieved through the inspection and testing process. This process can be conducted by the producer and contractor as QC and by the owner or the owner's representative as quality assurance (QA). Those involved in QC and testing need to know the unique characteristics of HSC to better assist the architect/engineer in evaluating the structure's potential performance.

Concrete with a specified compressive strength of 10,000 psi (70 MPa) can be produced from local aggregates in all areas of the U.S. and Canada. When the specified strength substantially exceeds that produced previously in a particular market area, special measures are necessary to make a successful progression to the use of the higher-strength concrete. This guide details those measures.

Because the definition of HSC has changed over the years, ACI Committee 363 defined a range of concrete strengths for its activities, as explained in ACI 363R. For the purpose of this guide, HSC is defined as having a specified compressive strength of 8000 psi (55 MPa) or greater, and it does not include polymer-impregnated concrete, epoxy concrete, or concrete made with artificial normalweight and heavyweight aggregates. Changes in material properties, production and inspection techniques, or testing methods occur continuously from lower-strength to higher-strength concretes. Experience shows that in most cases, the special measures recommended in this guide should be applied for concrete with compressive strength greater than approximately 8000 psi (55 MPa).