Question about development of headed reinforcing steel in tension (per ACI 318-19) 1

[cliff234]

Does anyone have ACI 318-19? I have a question about the ACI 318-19 requirements for development of headed deformed bars in tension. ACI 318-14 has numerous restrictions on the conditions for using headed anchors on reinforcing steel. Two of those restrictions are,

60 ksi upper limit on Fy
Minimum clear spacing between bars = 4 x bar diameter

Are these restrictions the same in ACI 318-19? (I am ordering my copy of ACI 318-19 today, but I’d like to get an answer before my copy arrives.)

 

[KootK]

There has indeed been some relaxation.

 

[Agent666]

ACI318-19 seems to completely change the actual equation (but I guess maybe you've received your copy by now and know that!), adding in a whole lot of other factors that can result in the worst scenarios having about double the development length for headed bars when compared with ACI318-14 requirement.

So while some detailing things have minor relaxation like above screenshot. In general things seem to have gotten a whole lot more onerous in certain situations. They used to be almost as good as a standard hook from memory, now they can be considerably worst depending on the scenario.