Check out "Historic Building Construction" by Donald Friedman. It's available on Amazon. It's a great reference for archaic building materials. I'm pretty sure he talks about the allowable bearing stress for brick masonry and sites references.
It's been awhile, but I think I've always used 100 psi for the allowable bearing stress in brick masonry.
WolfBuild - I have that book, it's not bad. I don't think it gives any recommendations for allowable stresses on masonry though.
CANEIT - Thanks, that's helpful. I've found people recommending a range of 100psi to 250psi as allowable for bearing.
I saw in an old eng-tips post that someone had mentioned having a copy of the paper I am asking about, I was hoping someone still had it. I'd like to see a study of testing to get a better sense of ranges.
Generally, for the ENGINEERED used of masonry, it has been found that the best measure of the compressive strength (and other properties) is a prism test. It is usually conducted on a prism with a h/t of 2, but correction values have long been established and accepted.
The results of prism tests have shown that mortar has a small effect of the compressive strength of a masonry wall and compressive strengths of the masonry units controls the engineered strength. - The mortar is in a thin horizontal layer perpendicular to the load and any failure is similar to confined compression, so it has little effect.
This may not apply to your needs, but selected units could be sample to determine the approximate strength of the masonry wall. - I have seen hollow masonry prisms with a compressive strength of 5000 psi with 2000 psi mortar. For solid brick, the effects of the mortar strength would be somewhat less.
Sorry, but I do not have a copy of the subject referenced.
Dick
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Engineer and international traveler interested in construction techniques, problems and proper design.