Hilti Profis Anchor Design Coefficients
Hilti Profis Anchor Design Coefficients
(OP)
Good-Morning, this is my first post so thank you for the help in advance.
I am using Hilti Profis to help in my first design of post-installed undercut anchors (I mainly deal with steel design).
I noticed that the software assumes a completely rigid baseplate, which distributes tensile loads to my anchors in an unrealistic manner. I have created a finite model to determine the actual distribution of loads to my anchors. I am then doing hand calculations, using the coefficients provided by the Hilti software to determine my concrete breakout strength. I have two concerns...
My "Hilti Design reports" are giving me higher values for several coefficients that I see in ACI 318-08. First, I am seeing a value of "0" for the critical distance where ACI uses 2.5*hef. A value of 0 concerns me, but ACI says if proved by tests other values of critical edge distance can be used (cac).
Next, they have a value of 30 for their coefficient of breakout strength (kc), when ACI 318-08 states "Kc is permitted to be increased above 17 for product specific tests but shall in NO CASE exceed 24". I know Hilti is a trusted name is the anchor world, so does anyone have any incite on these values?
I am using Hilti Profis to help in my first design of post-installed undercut anchors (I mainly deal with steel design).
I noticed that the software assumes a completely rigid baseplate, which distributes tensile loads to my anchors in an unrealistic manner. I have created a finite model to determine the actual distribution of loads to my anchors. I am then doing hand calculations, using the coefficients provided by the Hilti software to determine my concrete breakout strength. I have two concerns...
My "Hilti Design reports" are giving me higher values for several coefficients that I see in ACI 318-08. First, I am seeing a value of "0" for the critical distance where ACI uses 2.5*hef. A value of 0 concerns me, but ACI says if proved by tests other values of critical edge distance can be used (cac).
Next, they have a value of 30 for their coefficient of breakout strength (kc), when ACI 318-08 states "Kc is permitted to be increased above 17 for product specific tests but shall in NO CASE exceed 24". I know Hilti is a trusted name is the anchor world, so does anyone have any incite on these values?






RE: Hilti Profis Anchor Design Coefficients
As for the other factors, Hilti does extensive testing and posts all the ICC reports. They are also generally helpful if you give their guys a call with your questions.
RE: Hilti Profis Anchor Design Coefficients
Thanks for the input, I think I will give them a call as soon as I have a preliminary design completed.
This is embarrassing, the Kc value of 30 was due to me using uncracked concrete instead of cracked concrete on the drop-down. That issue has been resolved, I now get a Kc value of 24.