ACI 318-19 Building Code debuts with new aggregate, SCM provisions

Sources: American Concrete Institute, Farmington Hills, Mich.; CP staff

ACI 318-19 Building Code Requirements for Structural Concrete has been released in print and digital formats. The new edition has full-color illustrations to improve clarity, and includes major technical changes in higher reinforcing steel yield strengths; added shotcrete and deep foundation provisions; seismic requirements for deep foundations and other applications; vertical seismic motions; nonlinear analysis for seismic design; modification to development length equations; and, updated shear design provisions and equations. 

ACI 318-19 permits alternative cements as well as crushed hydraulic-cement concrete or recycled aggregate; however, it does not cover specifications for design criteria and performance for either alternative cements or aggregates because not enough industry testing has been done. Any alternative materials must be approved by the licensed design professional and the building official; hence, material suppliers and concrete producers will be responsible for performing testing and providing data on the expected product performance.

When it is decided during the design phase to use an alternative cement or aggregate, suppliers and producers can expect general information on the required characteristics of that alternative to be included in the contract documents, along with identification of appropriate submittals to validate the assumptions of material characteristics. Any project-specific issues would be identified and resolved early in the design process. An equally likely scenario is that the proposal of an alternative material could occur during the bidding or construction phase of a project. In this circumstance, the supplier’s ability to have data on-hand to confirm the material’s fundamental structural characteristics becomes critical to avoid delays. It is hoped that once data for a given product or process have been generated, they should have applicability for many other circumstances.

ACI 318-19 addresses a variety of other industry matters, among them provisions on post-tensioning, precast concrete, concrete durability and lightweight concrete. The document identifies training programs for inspectors/installers and lists certification requirements. It is anticipated that the final code requirements of ACI 318-19 will be referenced in the 2021 International Building Code. 

“ACI 318 is one of the most essential and valuable standards with respect to the design of concrete structures. The United States and countries around the world base their national building codes on all or part of ACI 318,” affirms ACI Committee 318: Structural Building Code Chair Jack Moehle, PhD, PE. 

The document in various formats can be ordered through the ACI website, Versions are currently available in English with inch-pound units and Spanish with SI units; additional versions and languages will be available soon. ACI 318-19 is also immediately available to subscribers of the online ACI Collection of Concrete Codes, Specifications, and Practices. ACI 318 Plus, a new product currently in development and targeted for mid-2020 launch, will provide subscribers with digital/interactive access to ACI 318-19 along with access to related resources. Additionally, the Institute is hosting public and in-house seminars to introduce users to ACI 318-19. Schedule and locations are posted at


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