Hi, when using adhesive anchors into grouted CMU walls, most of the capacity tables have a footnote that direct to have only one anchor per masonry cell. However, in the same tables, a minimum spacing of 4" is listed and per one of the footnotes, reduced capacities are provided and the installation is recommended (see attached file).
In the case where the course we are anchoring to is a bond beam (fully grouted course), can we have more than one anchor per cell while maintaining the minimum 4" spacing and using the appropriate spacing reduction factor to get the reduced capacity of the anchors? Or do we need to maintain one anchor per cell even though all the cells in that course are fully grouted due to the presence of the bond beam? Typical masonry cells are 8" long which could result in having 2 anchors in the same cell while maintaining a 4" spacing.
Hi Ruchin,
The limitation comes from testing and how the anchors performed during the tests per AC58. Different anchors may have different requirements.
Regards,
Dani
Hi Dany,
The testing that was performed with HIT-HY 200 in grout-filled CMU was done with one anchor per cell. Therefore, Hilti does not have any testing or reduction factors for the use of two anchors in one masonry cell. In the past, engineers have used methods such as onsite testing to help determine if the connection is suitable.
Regards,
Ashley