ACI 318-08, Chapter 12 is the basis for this table.
The development lengths for standard hook bars in tension for ACI 318-08 is given in Article 12.5
Standard hooks (with 90-deg or 180-deg bend) are defined in Art. 7.1 of the ACI Code.
A modification factor of 0.7 is applied to the basic development length in the above table. Therefore, the side cover (normal to the plane
of hook) for bars #11 and smaller shall be greater than or equal to 2.5". For 90-deg hook, cover on bar extension shall not be less than 2".
No stirrups or ties are assumed to occur within the development length, l dh .
Standard hooks shall not be considered to be effective in developing bars in compression.
The development length of deformed bars in compression for ACI 318-08 is given by Article 12.2.3
The development length of deformed bars in compression has been calculated assuming that no spiral or ties enclose rebar to be developed.
Stirrups Bars and Hook Bars
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