SHEAR-STRENGTH OF UNCHECKED GLUED-LAMINATED BEAMS

The allowable stress in shear is derived from shear tests of small cle ar shear blocks, but the shear strength of shear blocks is much greate r than the shear strength of larger beams. In this study, glued-lamina ted beams were tested to determine shear strength. These specimens wer e tested in the five-point bending test configuration. Shear blocks we re cut from the beam after failure and tested for shear strength. From these tests, a relationship between shear strength and beam size was developed that uses American Society for Testing and Materials (ASTM) shear block strength as a basis. The recommended relationship is based on test results for a number of sizes of Douglas-fir and southern pin e unchecked glued-laminated beams. This recommendation also includes t he stress concentration factor to account for the effects of the re-en trant corner in the ASTM shear block specimen.