The Concrete Chapter of the 2012 IBC - Problem and Suggested Solution

The concrete chapter of the 2012 IBC, Chapter 19, references ACI 318-11, the standard for concrete design and construction. The concrete chapter of the 2012 IBC continues to include a small number of modifications to ACI 318. These modifications are still based on ACI 318-08, which was the referenced standard for concrete in the 2009 IBC. This makes the modifications in the 2012 IBC inconsistent with the 2011 edition of the ACI 318 standard. Two significant changes from ACI 318-08 to ACI 318-11 contribute to this inconsistency. First, design and detailing requirements for wall piers that are part of special shear walls (for use in buildings assigned to SDC D, E, or F) are now included in ACI 318-11. Second, the design provisions for anchors subject to seismic design forces in SDC C-F have changed quite significantly in ACI 318-11. This is likely to cause confusion as designers try to use Chapter 19 of the 2012 for design purposes, following the adoption of this edition of the IBC.

This web seminar briefly traces the origin of the problem, goes over the modifications to ACI 318, as printed in Chapter 19 of the 2012 IBC, and, importantly, suggests needed adjustments to a number of the modifications to make them consistent with ACI 318-11. Adjustments to Section 1905.1.9 modifications to ACI 318 Appendix D are not simple and are therefore discussed in detail in the seminar.