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Column rebar lap length

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Josh_Structural_Eng

Civil/Environmental
Joined
Aug 23, 2016
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Is the lap length of vertical rebar in columns effected by the strength of the concrete? For example if I have 9ksi concrete for levels 10-20 and 8ksi concrete for levels 20-30, would I need a longer rebar lap length for columns in levels 21-30 than in levels 10-20? I am working reviewing rebar in a column shop drawing. Attached are the concrete notes and the lap chart that has been used in every column no matter what the concrete strength is.
 
Yes, the development length equation (in ACI and AASHTO at least) is mildly affected by concrete strength.

That said, it looks like the table provided assumes 6ksi (and provides modification factors for other strengths). For 8 and 9ksi concrete, the raw lap lengths provided in the table would be slightly conservative.
 
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