CMU

Example $1.$ A hollow concrete masonry unit has actual gross dimensions of $7-5/8$ in$.7-5/8$ in$.15-\frac{5}{8}in.($width $x$ height $x$ length$).$ The unit is tested in a compression machine with the following results:

Failure Load $=250$ kips

Net volume $=366\mathrm{.}9i{n}^3$

a$.$ Calculate the gross area compressive strength

b$.$ Calculate the net area compressive strength