reducing development length by 20
 

reducing development length by 20%
in aci 318-05 and also 318-08, section 12.2.2 commentary, it is stated that "in the development of aci 318-95, a comparison with past provisions and a check of a database of experimental results maintained by aci committee 408 indicated that for no. 6 deformed bars and smaller as well as for deformed wire, the development lengths could be reduced 20 percent using psi s = 0.8."
am i reading this right, and is anyone doing this, i.e. reducing their development lenghts by 20 percent for no. 6 bars or smaller? thanks.
this is a pretty common reduction. it's even taken into account automatically in the handy table they give you in 12.2.2 - that is the difference in the coefficients (1/25 compared to 1/20, and 3/50 compared to 3/40).
thank you very much, structuraleit. i take it that the 20 percent reduction has already been applied, and that we cannot take any further reduction.
that is correct if you are using the formulas in the table in chapter 12. if, however, you use the general equation it will have the psi s term in it. you will want to use 0.8 for #6 bars and smaller.