Referring to Fig. R17.7.2.1a & Fig. R17.11.3.1 from ACI318-19 (refer attached sketch), these are the two similar concrete breakout failures one in case of Anchor bolts (case 1) and other for shear lug (case 2).

In both cases, concrete breakout will result once force is transferred from anchor bolt (in case 1) and from shear lug (in case 2).

RAM currently checks shear reinforcement for case 1. However, for case 2, no shear check is performed in RAM.

“Anchorage Design for Petrochemical and Other Industrial Facilities (second edition)” states following:

“The changes in shear lug design based on ACI 318-19 require bigger pedestals than previously required with ACI 349-13. The larger pedestals can be avoided if reinforcing steel is added and properly designed to prevent concrete breakout in shear from the shear lugs.”

In example 4 of the same document, following comment is mentioned:

“Note that the allowable concrete breakout strength severely limits the capacity of the shear lug when compared to older designs based on ACI 349. The engineer should consider using the concepts for shear reinforcement demonstrated in Example 2 to allow for higher shear capacities.”

My understanding is, shear reinforcement check should be performed in case 2 for concrete breakout. Hence request you to consider my observation and incorporate this check in RAM.