Shear Strength due to Dowel Action Across Joint in Masonry CMU
Shear Strength due to Dowel Action Across Joint in Masonry CMU
(OP)
I am looking for some guidance on how to determine the design shear strength for chord horizontal bars crossing an "open" 0.375 inch wide vertical control joint in an 7.625 inch wide fully grouted CMU wall.
The mechanism is similar to shear friction with smooth surfaces, except there is actually a gap, so no interface / interlock friction at all.
I don't think ACI 530-13 discusses shear friction at all, and ACI 318-14 has some brief language in the commentary.
Existing construction - redesign is not an option.
Primary demand at joint is out-of-plane seismic per ASCE 7-10 Section 12.11.
I'm guessing the governing limit states are
1) CMU shell crushing at the vertical faces, and
2) shear stress in horiz rebars, and
3) bending stresses in horiz rebars.
Any defensible code guidance, or rational extension from published codes? I practice in California.
The mechanism is similar to shear friction with smooth surfaces, except there is actually a gap, so no interface / interlock friction at all.
I don't think ACI 530-13 discusses shear friction at all, and ACI 318-14 has some brief language in the commentary.
Existing construction - redesign is not an option.
Primary demand at joint is out-of-plane seismic per ASCE 7-10 Section 12.11.
I'm guessing the governing limit states are
1) CMU shell crushing at the vertical faces, and
2) shear stress in horiz rebars, and
3) bending stresses in horiz rebars.
Any defensible code guidance, or rational extension from published codes? I practice in California.






RE: Shear Strength due to Dowel Action Across Joint in Masonry CMU
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RE: Shear Strength due to Dowel Action Across Joint in Masonry CMU
RE: Shear Strength due to Dowel Action Across Joint in Masonry CMU
Crushing capacity (phi-Bvnc) for f'm = 1,500 psi and 5/8" bolt (or rebar) = 2.44 kips
heynewp - the vertical movement joint (control joint) was aligned above one vert edge of a 10'x10' roll up door opng. The wall has 2-way behavior.