ACI 318 Editions and ACI 211.1-22: What Changed
ACI 318 and ACI 211.1 are both periodically reissued. This page gives a conceptual overview of the direction of change across recent editions, without citing exact clause numbers or figures that vary by edition.
Why editions matter
ACI 318, the structural concrete building code, is revised on a multi-year cycle (recent cycles include the 318-14, 318-19, and 318-25 editions). Each revision is adopted into local building codes on its own timeline, so the edition that legally governs a given project depends on which edition the applicable building code has adopted as of the project's permit date — not simply the newest one published. This is exactly why this site avoids stating specific numeric durability limits: those limits are the kind of value most likely to be adjusted between editions.
The general direction of travel
Across recent editions, ACI 318's durability and exposure provisions have generally moved toward more explicit categorization of exposure conditions and closer integration between the durability requirements and the rest of the structural design provisions, rather than leaving durability as a secondary check. The overall structure — assigning exposure categories along independent scales, and setting a maximum w/cm and sometimes a minimum strength for each — has been consistent across recent editions, even as specific figures and organizational details have been refined. Treat any specific number you see online, including on this site, as something to verify against the current edition rather than take at face value.
ACI 211.1-22
ACI 211.1, the standard practice for selecting proportions for normal, heavyweight, and mass concrete, was reissued as ACI 211.1-22. This is the edition this site's calculator follows. The underlying absolute-volume proportioning method — working from mixing water, water-cementitious ratio, and aggregate content to a full batch design — is long-established and has remained structurally stable across editions; reissues of this kind typically update references, formatting, and supporting commentary rather than replacing the core method itself.
Frequently asked questions
Which ACI 318 edition applies to my project?
Whichever edition is referenced by the building code adopted by the jurisdiction where the project is built, as of the applicable permit or design date — not necessarily the newest published edition. Confirm this with the local building official or the project specification.
Did ACI 211.1-22 change the mix design method itself?
ACI 211.1-22 is a reissue/reapproval of the long-standing absolute-volume proportioning practice, not a replacement of the underlying method — the step-by-step approach this site follows has been stable across editions, though editorial and reference updates do occur.
Does this site track a specific ACI 318 edition?
This site explains the concepts and structure of ACI 318's durability requirements without publishing specific numeric limits, precisely because those figures are revised between editions. Always check the exact figures in the edition that governs your project.