The objective of this study was to improve current shear design criter
ia by establishing a test method for creating a database of beam shear
strength of solid-sawn Douglas-fir lumber and correlating it to shear
block test results; verifying whether the beam-size equation is a val
id correlation between shear strength and beam size for solid-sawn mat
erial; and determining whether shear strength is more dependent on she
ar area, volume, or depth for modeling purposes. Experimental results
are presented for 160 shear strength tests on unsplit, green, sawn No.
2 or better Douglas-fir lumber. Five different size specimens, rangin
g from 38 by 89 mm (2 by 4 in.) to 38 by 337 mm (4 by 14 in.), were te
sted in five-point beam shear. ASTM D143 shear block miners were cut a
nd tested from each beam. Results adjusted to 12% moisture content wer
e compared with prior research on southern pine and Douglas-fir glued-
laminated timber beams. Statistical methods of censored statistics and
regression investigated the following possible correlations: shear st
rength to beam size and beam shear strength to ASTM shear block streng
th. Results indicate that (1) a five-point test setup can consistently
produce beam shear failures over a wide range of beam sizes; (2) shea
r strength is dependent on beam shear area; and (3) beam shear strengt
h is related to ASTM D143 shear block strength values provided the ree
ntrant corner stress-concentration effects are considered.