Masonry Retaining Wall - Reinforcing ?

[ChipB]

I am designing a 12' high ret. wall. The block's f'm=2000 psi. It's 12" retaining wall block which is the type with grooves cut into it for horizontal reinf. My reinf. steel's Fy=60ksi. I called out for #8s @ 8" for vert. reinf. 3" from the soil side. The contractor wants to use a lesser bar. I have the horizontal reinf. I can tie to. Anyone see a problem with calling for (2) #6s in each cell at the same location as the original w/ 3" between them? I am using special inspection and am going to make them tie to the horizontal steel to maintain this distance

 

[denoid]

If the reinforcing is lap spliced, which it will likely be for a 12 foot tall wall, you could have a few cells with the equivalent of 4-#6 bars in a cell. Add this to any hozizontal bars you may have in the grooves, and it doesn't leave a lot of room for grout!

 

[CSEllc]

In my opinion, using (2) #6's in a core is difficult. With 12" CMU, the cores are about 6" x9". trying to get grout arond a single bar in a CMU wall is difficulkt. Trying to get grout around (2)#6's vertical + (2)#6 dowels or splice bars will be next to impossible. Stick with the #8's

Better yet, switch to a concrete wall, you will probably cut the reinforcing steel required by a 1/3.

 

[CABaker]

Definitely keep it to a single bar per cell for ease of placement and grouting purposes.