effective embedment depth in concrete breakout check of Hilti Profis

Hi Yong,

Thank you for reaching out. Based on the geometry of the design in the report you attached, it appears the reason h_ef is reduced for concrete breakout and pryout would be due to a three edge condition being met per ACI 318-19 Section 17.6.2.1.2. This occurs when anchors are located less than 1.5*h_ef from three or more edges.

As a note, your file appears to be based on ACI 318-11, where similar verbiage is shown in Section D.5.2.3.

ACI 318-19


ACI 318-11

In those cases, the h_ef is reduced to the maximum of {c_a,max / 1.5 , s/3 }, which yields the 20” you are observing for the concrete breakout in tension (and, consequently, pryout) calculations.

I hope this helps. If you have additional questions, please reach out to hnatechnicalservices@hilti.com with your .pe file.

Kind regards,
Sinan