90 Degree Rebar Coupler 2

[waytsh]

I need to make a 90 degree connection with #11 bar (not enough room to make the bend) and was wondering if anyone knows of a standard coupler? Internet searches have turned up nothing.

If no such creature exists I am considering using a heavy 2.5" x 2.5" square corner bar and Lenton welded couplers to attach the reabr to the sqaure bar. Does this sound reasonable?

Thanks!

 

[Teguci]

Use weldable reinforcement (A706 I think) and weld it directly to the plate. This is common in precast haunch construction. Bars laid against the plate are welded with groove welds and end on bars are welded with fillets all around. The plate is used as the bearing surface for the haunch.

The development of your #11 bar will need to be checked. In this case, the bearing of the plate should be looked at.

 

[waytsh]

Good point about checking the bearing. My goal was to keep the bar continuous around the corner but you're right in this configuration my corner bar would be acting like a dead end anchor. Just to give a little more background this is the corner of a large flat beam and is where I am going to have the largest moment so it is essential that I keep the continuity. This is why I started looking at this sort of connection once I realize that I wasn't going to have the clearance for a standard hook.

I was looking at the couplers because the fabricator said that the weldable bar is more expensive than the standard and the cost of the couplers would not have that much of an impact. I have not checked any of the costs so I just have to go off of what they are telling me. The coupler I am looking at threads into the rebar and then welds to the plate so there would really be no need for weldable bar. Maybe I better have them take a second look at it to be sure. I do like the detail you described though, what grade of steel would you normally specify for the plate for welding the reinforcing bar to it?

Thanks.

 

[Teguci]

I don't think you would need anything more than A36 for the plate. As an alternate, Erico provides splice terminators. This is a headed attachment that threads onto the reinforcement and reduces development length.

I assume you've tried going with smaller diameter bars. Typically, where you can't get development of bars into a column, you increase the size of the column. Reinforcement congestion can be a considerable problem when they build the column.

Are we talking about a column to beam connection that carries moment from the beam into the column? Is this the top beam (ie the column stops at the top of the beam)?

 

[waytsh]

Yes, smaller bars will not work.

This is a stiffener beam at the top of a concrete tank. It is 1' deep by 4' wide. The beams probably should have been bigger but unfortunaltly we didn't see how tight things were going to be sooner and have moved pretty far down the road on this project. Changing it now would be a major disaster for the schedule. So if I can get it to work this way it is going to be the route we will have to take.