ACI 311.6-18 – Specification for Testing Ready-Mixed Concrete

ACI 311.6-18, “Specification for Testing Ready-Mixed Concrete,” is a relatively new ACI standard,
and this particular ACI standard is targeted to specification writers. There are probably more people
within the design and construction community who haven’t heard of it than those who have. ACI
311.6 is not adopted by the International Building Code (IBC) nor the concrete code (ACI 318);
therefore, it is not code, even by reference, at this time. However, regardless of your role within the
design and construction community, you should read ACI 311.6 because the content is important.

ACI 311.6 does not appear to conflict with standard code compliance criteria required of the special
inspector or the contractor. The standard primarily stipulates compliance with ASTM testing and
inspection criteria specified in ASTM standards C143, C1064, C173, C138, C31, and C39. These
standards address slump, concrete temperature, air content, concrete unit weight, making concrete
test specimens, and testing concrete test specimens, respectively. All of these ASTM standards and
the ASTM compliance criteria they include are already required by the IBC and/or the concrete code
(ACI 318).

Verbiage is addressed directly to specifiers regarding the inclusion of ACI 311.6 in the contract
documents. Minimum test report content is required by Section 3 of ACI 311.6, but this amounts
to less data than is already required by existing code compliance criteria. Some mandatory and
optional checklist requirements similar to ACI 301 also exist (which, incidentally, all concrete
specifications include).

Future contract documents will likely include ACI 311.6-18. The real takeaway from this Speaking in
Code BLAST is that ACI 311.6-18 imposes no additional compliance criteria on industry professionals
than is already required.

For more information or further enthusiastic discourse on topics of CODE,
please contact Alan Tuck at: or 540.344.7939

ACI 311.6-18 Specification – Testing Ready Mixed Concrete
1.1.1 Work Specified – This specification sets the minimum
requirements for testing of ready mixed concrete at the project site when specific field tests and specimens prepared for laboratory test properties including strength are used as a basis for acceptance of concrete as delivered to the site.