Importance of performance certification for post-installed anchors: An experimental assessment

This study evaluates the pullout performance of ETA-approved and non-ETA-approved post-installed bonded and mechanical torque-controlled expansion anchors found in the Middle East region, and draws conclusions on the role of such performance certifications on ensuring the safe operation of the anchors under various installation and site conditions. Both, the bonded anchors and mechanical expansion anchors were studied with a total of 106 tests, including tests in cracked concrete and elevated temperatures of 60 degrees C. Results found that ETA-approved anchors retained a larger portion of their reference strength and were more robust at suboptimal site conditions. Non-approved bonded anchors retained just 24% of their reference strength under the common scenario of workers neglecting the cleaning of the drilled holes. Bulk bonding adhesives manually mixed by the user could have critical results if the mixing ratio is not strictly followed and the non-approved mechanical anchors lacked sufficient instructions, had a lower build quality, and could not generate a sufficient clamping force regardless of installation torque.

Automated summary

This study found that ETA-approved anchors performed better under suboptimal site conditions, while non-approved anchors retained only a portion of their strength in common scenarios, posing safety risks.