Toughness properties for several composite lumber materials

An exploratory study was conducted to establish toughness properties for several structural composite lumber (SCL) materials including laminated veneer lumber (LVL), parallel strand lumber (PSL), and laminated strand lumber (LSL). Toughness as a mechanical property was determined following provisions of the American Society for Testing and Materials (ASTM) standard method ASTM D 143. Test evaluations were performed for both edgewise and flatwise material orientations to characterize toughness performance. Presented are the impact to failure resistance results collected for 10 different SCL materials with comparison to solid wood property values. Test results indicate LVL can have noticeably higher toughness performance. Southern pine LVL materials tested on average had 29.9 percent higher toughness when examined in comparison to published wood property values. Other veneer-based composites tested in the form of Douglas-fir and yellow-poplar LVL were closer to solid wood performance. Commercial strand-based composites in the form of PSL and LSL generally had impact resistance to failure below the corresponding values cited for solid clear wood.