Changes to the IBC 2012 Anchor Code
Code Landscape for Adhesive Anchor Systems
Beginning January 2015, ICC-ES Evaluation Service Reports (ESR’s) for adhesive anchor systems will list compliance with the 2012 International Building Code (2012 IBC). There are some notable changes with respect to the information contained in these reports, as well as the manner in which this information is presented. This paper provides a brief overview of the changes that have been implemented into 2012 IBC-compliant ESR’s, and how these changes affect adhesive anchor design.
The IBC references the ACI 318 Building Code. Each code is published on a three year cycle. Therefore, the 2009 IBC references ACI 318-08, the 2012 IBC references ACI 318-11, etc. Adhesive anchor systems used with the anchor provisions of the ACI 318 Building Code and the IBC codes must be qualified via testing. The ACI 318-11 Building Code Anchoring to Concrete provisions in Appendix D require post-installed adhesive anchor systems to be tested and evaluated in accordance with Qualification of Post-Installed Adhesive Anchors in Concrete (ACI 355.4-11). ICC-ES Acceptance Criteria are used to establish requirements for post-installed anchors for recognition under one of the IBC codes. Recognition is provided via an ICC-ES Evaluation Service Report (ESR). The ICC-ES Acceptance Criteria for Post-Installed Adhesive Anchors in Concrete Elements (AC308) is currently used to establish post-installed adhesive anchor requirements for recognition under the current IBC codes. Part 1 EVALUATION SCOPE in the ESR will note the IBC codes for which the anchor system has obtained recognition. Beginning with ESR’s issued in January 2015, Part 1 will note compliance with the 2012 IBC for adhesive anchor systems that have been tested in accordance with AC308 and ACI 355.4-11. These anchor systems can be used with the anchor provisions of IBC 2012/ACI 318-11 Appendix D, IBC 2009/ACI 318-08 Appendix D, and any additional IBC code listed in Part 1 of the report along with the corresponding ACI 318 Building Code version.
ACI 355.4 was developed for use with the adhesive anchor provisions of ACI 318-11 Appendix D. Prior to ACI 318-11, adhesive anchor provisions were not included in the scope of Appendix D. Therefore ACI 318-08 Appendix D did not include any provisions for the design of adhesive anchor systems. The ICC-ES Acceptance Criteria AC308 did, however, include provisions for qualification testing of adhesive anchor systems, as well as equations for calculating the bond strength of an adhesive anchor system. The bond strength equations were also given in the 2009 IBC-compliant adhesive anchor system ESR’s. Therefore, adhesive anchor ESR’s having the 2009 IBC recognition could be used to calculate a design bond strength using the AC308 equations. Since the 2009 IBC references ACI 318-08, the provisions of ACI 318-08 Appendix D could be used to calculate the other relevant design strengths
ACI 318-11 Appendix D includes provisions for the design of adhesive anchors via a new section denoted Part D.5.5. Since adhesive anchor provisions are now included in the ACI 318 Building Code, bond strength equations are no longer included in AC308. Adhesive anchor qualification is now determined in conjunction with ACI 355.4 and AC308, and bond strength equations are only given in ACI 318-11 D.5.5. Furthermore, since ACI 318-11 D.5.5 now includes bond strength equations, and the 2012 IBC-compliant ESR’s reference ACI 318-11, the ESR’s no longer need to include bond strength equations. Therefore, the ACI 318-11 D.5.5 equations are the only equations relevant to adhesive anchor bond strength calculations for any of the IBC’s referenced in the 2012 IBC-compliant ESR’s. For example, ESR-3187 issued January, 2015 for HIT-HY 200 lists recognition for the 2012, 2009, and 2006 IBC; however, since the only adhesive anchor design provisions now available are those given in ACI 318-11 D.5.5, adhesive anchor design under the 2006 IBC/ACI 318-05, 2009 IBC/ACI 318-08 as well as the 2012 IBC/ACI 318-11 must be performed using the design provisions of ACI 318-11 D.5.5.
Adhesive Anchor Design
Adhesive anchor design under the 2012 IBC will be performed using the provisions of ACI 318-11 Appendix D. Bond strength calculations will be performed using the provisions of Part D.5.5. These provisions will be used in conjunction with the provisions and tables contained in the ESR. The characteristic bond strength values (τk) that are given in the tables containing BOND STRENGTH DESIGN INFORMATION have been revised from the values shown in previous ESR versions. The maximum short term/maximum long term concrete temperatures for Temperature Range A have been increased to 1300F/1100F respectively. The characteristic bond strength values (τk) based on these temperatures are correspondingly reduced.
PROFIS Anchor will use these revised bond strength values to perform bond strength calculations when ACI 318-11 and ACI 318-08 have been selected as a design option. PROFIS Anchor will likewise use the ACI 318-11 D.5.5 provisions to perform bond strength calculations when ACI 318-11 and ACI 318-08 have been selected as a design option.