I received an RFI requesting the number of days after grout placement that anchor rods can be installed into fully-grouted CMU walls. Project permits HY-70 and HY-270. Both product ICC approvals indicate minimum f'm = 1500 psi at 28 days. Does the contractor need to wait the full 28 days before installation of the anchors, loading/testing of the anchors, or just until f'm achieves 1500 psi?
Hi James,
The most important aspect of the grout cure is to ensure that there is a minimum compressive strength of 1,500 psi. If the grout has a compressive strength of 1,500 psi before 28 days have passed, the decision to install the anchor would be up to the Engineer of Record for the project.
If you would like to discuss this further, please reach out to hnatechnicalservices@hilti.com or 877-749-6337.
Regards,
Ashley