huangyhg

cmu horizontal joint reinf.
do any of you have any preference between truss type or ladder type horizontal joint reinf.? they both seem to meet the code requirement for shear walls (two w1.7 wires)

truss type is used in single wythe cmu. ladder type is used for cavity wall composed of brick and cmu. in a cavity wall brick swells and cmu shrinks. truss type in a cavity wall would likely cause cracking because of the restraint provided by the diagonal wires.
truss type is much more difficult to deal with in the field. the diagonal crosses cells and interferes with rebar and makes itself a general hassle.
at one time the corps of engineer's did not allow truss type horizontal reinforcing as the "interior chords" might interfere with grout placement. i'm not sure if it's still prohibited.
-jack
contractors prefer ladder type, easier to deal for reiforced masonry
ucfse is right; truss type is much more difficult to deal with in the field because the diagonal wires cross the cells and interfere with rebar placement.
am on a job right now where the parking deck barrier walls have #7 bars at 8". with the required lap of 79" and the fact that a mason can lift a block over a 7' bar max every cell has two #7 bars. have to take special precaution to ensure that no wires cross the cells.
boffin, that sounds like a back-breaker of a day! i think that would make mechanical splices at least worth looking in to.

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