Written by James J. Hahn, Product Manager
US Anchor Division • Brighton-Best International
The damage from earthquakes, hurricanes, flooding, and wind forces to various structures has led to increasingly stringent building codes to ensure safety.
There’s a process to identify weaknesses in structures and attachments after these events occur to assess their ability to meet established standards. This also extends to various types of anchoring products.
The types of anchors used for construction and industrial applications are segmented into light, medium, and heavy-duty categories. Adhesive anchors offer an alternative, non-mechanical option for forming attachments in concrete and masonry base materials, and typically for anchoring threaded inserts.
• Light-duty – Leads, lags, machine screws, single/double expansions, drive types, wallboards,
plastic nylon types, and toggle bolts.
• Medium-duty – Concrete screws and sleeve anchors.
• Heavy-duty – Wedge type, larger diameter concrete screws, and drop-in types.
• Adhesive anchors – Epoxy and polyester products used in conjunction with B7 studs or other
Meeting the codes
Building codes were established to assess the ability of products to meet or exceed standards. These codes are reviewed and updated continuously. Medium and heavy-duty mechanical anchors, and adhesive anchors, are typically (and ideally) tested to meet these code approvals.
Who establishes these codes? Concrete fastener criteria fall under ASTM codes and the concrete criteria are under the American Concrete Institute or ACI codes.
ASTM is an international standards organization, formerly known as the American Society for Testing and Materials, which develops and publishes voluntary consensus technical standards for various materials and products. ACI sets forth proper methods of designing and constructing buildings of reinforced concrete.
These codes are reviewed by esteemed members of the engineering community who are members of key committees. Their assessment of changes to existing codes is accomplished by consent after thorough review. In many cases, product testing criteria are reviewed and updated based on new findings and recommendations.
National code agencies have also evolved to establish evaluation and approval processes. Some of these agencies are regional and others are national.
There is continuous dialog and coordination among international code agencies to update testing criteria, which is handed down from the code committees as guidelines for testing.
There are two main domestic agencies:
1. International Code Council Evaluation Service (ICC-ES), a premier product certification program for North America
2. Miami Dade County for code compliance and ordinances
These agencies have, gradually, adopted similar processes and requirements. As a result of hurricanes and the presence of salt air and water, Miami Dade County requires corrosion testing as part of its approval process. Wind considerations are also another area of concern and part of their evaluation process.
The ICC-ES emphasizes applications affected by seismic events and, particularly, in the western United States. New code requirements include tie-downs for residential and commercial buildings for structures including concrete slabs, roof connections, and others.
Cracked and uncracked concrete evaluation is also now an established testing criterion to meet anchor codes. This testing process is extremely sophisticated, and costly, with only a handful of testing labs capable of completing these tests.
In addition to mechanical anchor testing, epoxy and certain adhesive products must meet the requirements of the code agencies.
Testing entities must meet the strict requirements and be sanctioned by the evaluation and approval agencies, which includes periodical inspections. These labs are considered third-party entities and must have “an arm’s length” relationship with the manufacturers of the products that are undergoing testing.
The testing labs are headed up by professional engineers (P.E.) who oversee the actual testing protocol and coordinate all activities with the code agencies. Typically, the code agencies assign a lead engineer who works with the testing labs P.E.’s until the final evaluation is completed and the approval published.
Types of testing
There are several types of tests, depending on the anchor and its intended use. The tests help verify the structural strength of the anchoring system or base material. Certain tests require lab work and others can be done onsite at the job.
• Site-specific – This is testing done at a job site instead of at a testing lab. Typically, anchors are specifically tested to the contractor’s onsite, concrete conditions.
• Pull-out – Also known as tension characteristics, this test extricates an anchor upwards and out of the hole in the concrete.
• Shear – This is a lateral test of the steel body’s strength.
• Edge and spacing – anchors are tested at both minimum and critical distances.
• Embedments – Anchors are tested at various hole depths to include minimum and normal embedment requirements.
• Secondary testing – There are additional non-critical tests to round out the overall testing program.
There are also manufacturing or factory requirements, designed to ensure the overall integrity and reliability of anchors and the application.
These often include:
• A bi-annual inspection that’s completed by the ICC-ES, with annual inspections by Miami Dade County.
• A Quality Manual, which is required and updated for review by inspectors.
• Equipment and best practices that are reviewed on site.
• The traceability of raw materials used in manufacturing must be verified.
Anchor packaging serves as an important indication of the anchor type, including its specs and instructions for installation — which are a must. The testing approval number and logo must be affixed on all anchor packaging.
Approvals and logos can be included in the spec sheets and marketing materials with some limitations.
Clearly, the testing of anchoring products offers considerable benefits. For the end-user, it’s an indication of a quality engineered product with testing results that support or exceed expectations. For distributors, it lets them sell and market an approved anchoring product with confidence.
Lastly, for a manufacturer, it’s a reward for their commitment to quality including the costs and time that was involved in the product development. Without such approvals, a product is considered generic with zero testing values to support the performance of a non-tested anchor product.
The following are critical and established requirements in the testing protocol for anchors used in construction and industrial applications.
- Concrete slabs must be poured to a specific psi (pounds per square inch). Additionally, they must be pre-tested and part of the final testing report.
- A statement of work (S.O.W) must be communicated to the code agencies and client before testing.
- The lead P.E. must oversee all aspects of the testing protocol.
- The concrete composition must meet the stated criteria in the S.O.W. declaration.
- Any product samples to be tested should be independently selected by the testing lab at the manufacturer’s warehouse and shipped directly to the lab.
- The testing equipment used must be calibrated prior to testing.
- All photos of the testing processes and results must be properly documented. The testing equipment should also be connected to a laptop computer to graph results.
- The carbide drill bits must be measured before and after each drilled hole.
- Testing results may indicate concrete breakout or steel failure.
- The testing lab should communicate regularly with the manufacturer, updating them on the ongoing process and results. At times, additional testing or redesign of the product is required.
- The final testing reports should be sent back to the evaluation agencies. The assigned evaluation engineer or examiner, then, arranges for an internal peer review before the final disposition and publication.
- Once approved, the report is published with a specific expiration date.