I am designing the anchorage for a leger channel to 6" CMU (ungrouted). Can you tell me how the shear bond strength is determined, is this a pryout check?
Also, the minimum masonry required wall thickness in the ESR says 7 5/8". Would a 6" cmu invalidate the profis design values?
Hi Jared,
PROFIS Engineering references “Bond Strength Parallel” and “Bond Strength Perpendicular” within the shear calculations. The software uses the term “parallel” to describe an edge that is found in a direction parallel to the direction of the shear load. Additionally, the software uses the term “perpendicular” to describe an edge that is found in a direction perpendicular to the direction of the shear load. For anchoring into masonry, the software performs multiple iterations based on the following parameters:
Load magnitude and direction acting on the anchors
Spacing and edge distance for each anchor
Modification factors based on parallel and perpendicular directions
Unfortunately, all of Hilti's supportive testing for HIT-HY 270 is based on CMU complying with ASTM C90 with a nominal size of 8" x 8" x 16", as stated in Section 3.4.1 of ESR-4143. Therefore, it will ultimately fall to engineering judgement to determine anchor performance in 6" CMU base materials.
Regards,
Matthew