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Using an over-strength factor

Posted by Stephen Maloneyalmost 8 years ago
Using an over-strength factor

*Posted on behalf of a Hilti customer:

The development length for post-installed rebar is equivalent to cast in place. If so, do we need to use over-strength factor?

rebar,AC308

1 Reply
Posted by Robert Walkeralmost 8 years ago
Hilti Verified

Hey Customer,

thank you for your question. Post-installed reinforcing bars that have been qualified per AC308 Table 3.8 for use with the development and splice provisions of ACI 318 can be designed for development with the same parameters as those used for cast-in-place bars. For example, the calculated development length for cast-in reinforcing bars in a boundary element of a special structural wall is multiplied by an over-strength factor of 1.25. Post-installed reinforcing bars that have been qualified per AC308 Table 3.8 can likewise be designed in a boundary element of a special structural wall using an over-strength factor of 1.25.

Use of the omega-0 over-strength factor in the earthquake component of a factored load is an anchoring-to-concrete parameter. Therefore, post-installed reinforcing bar design strengths calculated per the ACI 318 anchoring-to-concrete seismic provisions that include use of an over-strength factor would be checked against a factored load that includes an omega-0 over-strength factor. Don't hesitate to contact us if there is anything else we can do for you.

All the best
Robert