ACI Chapter 17 says concrete has to be at least 21 days old, but the conditions of use in Hilti ICC-ESR's says the concrete needs to reach it's minimum design strength. Which should I go by?
Hi Chris,
Thank you for reaching out. ACI 318-19 Section 17.2.2 requires adhesive anchors to be installed in concrete having a minimum age of 21 days at the time of anchor installation. Hilti adhesive anchor systems adhere to this requirement, with the concrete compressive strengths listed in the Evaluation Service Report. In general, both should be met.
In cases where the concrete has not reached the minimum of 21 days, Hilti has a technical bulletin for HIT-HY 200 V3 and HIT-RE 500 V3 available for the Engineer of Record to reference at their discretion. This is outside of the scope of the published Evaluation Service Reports.
I hope this helps. For additional questions, please reach out to hnatechnicalservices@hilti.com.
Kind regards,
Sinan