Almost all states have adopted the 2006 IBC and supplemented by AC 308 and AC 193 anchor qualification requirements. Here’s what installers need to know.

It’s been more than four years since the International Code Council (ICC) Evaluation Services-ES (ICCES) published the AC 308 and AC 193 criteria, two new construction acceptance criteria standards with far-reaching effects in the world of concrete fasteners.

The Evaluation Services division is an arm of the ICC, a non-profit agency dedicated to building safety and fire prevention. ICC develops I-Codes, which are a complete set of consistent, comprehensive, coordinated building safety and fire prevention codes for designers, engineers and construction contractors.

In 2006, the ICC adopted an updated set of codes that were consistent with state-of-the-art practices. It wanted to further assure that adhesive or mechanical anchors used in new construction could maintain their load-bearing capacity, even under adverse conditions. The code changes greatly affected anchor design and testing procedures, which some anchor manufacturers have worked aggressively to comply with.

Today, nearly all areas of the country have adopted the new code, and those who install the new codecompliant anchors must keep a few things in mind, report anchor industry professionals.

AC 308 and AC 193 standards clarified

“AC 308 deals with adhesive anchors and AC 193 addresses mechanical anchors,” says Mark Ziegler, director of engineering at Powers Fasteners. The standards are designed to assure the anchor will maintain its load-carrying capacity during its service life in a building, which is typically assumed to be 50 years. “There is some confusion about the new standard. It is fairly recent so there is some education needed, especially with code officials. The engineer of record and the code officials need to be in agreement on the code requirements in effect on projects under development. More seismically active areas have been adopting the new codes quickly, but we are in the middle of a transition to the requirements becoming fully enforced throughout the country,” he says.

In many circles, the new standard has been dubbed the “cracked concrete standard” but that’s a bit of a misnomer, says Craig Pratt, product manager at Simpson Strong- Tie Anchor Systems. “For adhesives, performance in cracked concrete is only one of many reliability and service condition tests under investigation. The test program for adhesives considers the impact of the presence of moisture during installation, less-than-perfect installation conditions, performance over a range of concrete strengths, sensitivity to adverse temperatures and exposure to sulfuric and alkaline environments. In addition, cyclic seismic load performance is evaluated as well as the influence of differing concrete mix designs.”

Pratt points out that to account for these factors, the code requires more detailed load calculations be performed by the design engineer. Most anchor manufacturers simplify this task by providing mathematical programs that assist the engineer in making these complex calculations. The engineer is then able to specify anchor type and capacity based on input demand.

To meet the new standards, manufacturers have developed new adhesive formulations and anchor designs that exhibit higher reliability during installation and during the life of the anchor. “The new standards require testing anchors installed under optimal conditions and then compare performance based on various adverse conditions,” says Pratt.

The new codes require anchor manufacturers to test anchors under the more stringent test and evaluation standards, and in many cases, required new anchor adhesive formulations and mechanical anchor designs, says Ziegler. "Code-compliant data and results are outlined in ICC-ES reports that are published for every anchor that is validated.“

What this means to construction contractors

Because design engineers and building inspectors have the most say over anchor specification, they must choose anchors that satisfy prevailing code requirements. From an installation standpoint, the current code-compliant mechanical anchors are installed in a very similar way as older style anchors.

However, different adhesive anchors have different installation instructions, and the contractor and building inspector must be aware of this. “'What is the installed cost?' is definitely a question the contractor should ask," says Pratt.

Anchor Category may cause some confusion, but Pratt explains it this way: ”There are three acceptable Categories for post-installed anchors: 1, 2 and 3, which address an anchor’s sensitivity to installation and reliability. It is important to note that Category is not a measure of load capacity. Associated with each Category is an appropriate load adjustment (phi) factor that is used by the engineer for design. Interestingly, a Category 3 anchor could possibly have a higher load carrying capacity than a Category 1 anchor,” Pratt says.

Substitutions

“Don’t assume you can substitute one anchor type with another anchor type. The engineer of record will decide if a product substitution is allowed. Code requirements set forth by the building inspector and design engineer are critical. As the industry adopts the new standards, be ready to show proof that the installed anchors meet the new code. ICC-ES Evaluation Service Reports (ESRs) are evidence that a product is compliant with the codes and applicable materials listed in the scope of the report.

The new building standards are designed to help minimize the failure of a mechanical or adhesive anchor if a crack forms in its embedment area.

Under the new code changes, some installation methods have changed slightly. The important thing is that the anchoring system being used meets the requirements outlined by the specifying engineer. Substitutions must be reviewed and approved by the engineer of record.