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Naturally durable wood species such as western juniper (Juniperus occidentalis) are a potential source of bio-based wood preservatives for the improvement of non-durable timber species. This research investigated the durability of southern yellow pine (Pinus sp.) and western juniper lumber or strandboard. Single layer panels were made with six different types of wood or wood treatments: southern yellow pine, mixed juniper sapwood and heartwood, sapwood, heartwood, sapwood strands impregnated with juniper oil prior to and after panel manufacturing. Panels were fabricated with 560 kg/m3 oven-dry density with 5% of PF resin and 0.5% of wax. Durability testing was performed with the brown rot fungi Gloeophyllum trabeum and Rhodonia placenta and the white rot fungus Trametes versicolor. Internal bond as a crucial parameter of OSB was measured. Tests revealed that juniper heartwood and juniper heartwood strandboards were highly decay resistant, and juniper oil pre- and postimpregnation strandboard manufacture imparted increased resistance to decay against one brown rot fungus, Gloeophyllum trabeum. Juniper strandboard manufactured from non-impregnated strands showed significantly higher internal bond than pine. These results suggest there is excellent potential for manufacturing highly decay-resistant OSB from juniper, especially from heartwood and that juniper oil can increase the durability of juniper sapwood strandboard. [ABSTRACT FROM AUTHOR]

The wood of poplar species is generally perceived as susceptible to decay, however, poplar is still widely used as columns in traditional Chinese buildings. Understanding how decay affects the compressive properties of this material will help engineers better assess wood condition during routine inspection and maintenance. The effects of decay on compressive properties of Chinese poplar were explored using a brown rot decay fungus (Gloeophyllum trabeum). Changes in compression strength were fairly linear and more closely correlated with mass loss (R2= 0,75). The results suggest that residual compressive strength could be roughly predicted using wood density as a surrogate measure. [ABSTRACT FROM AUTHOR]

The potential for polyurea coatings to improve wood crossarm performance was assessed on untreated and treated Douglas-fir exposed to termite/fungal attack in Hawaii. Treated materials performed similarly regardless of coating, although coating reduced UV damage. Untreated non-coated timbers were decayed within 2-years of exposure and were unserviceable after 7 years. Upper surfaces of coated, untreated samples experienced pronounced coating loss and contained advanced decay on the undersides of the timbers, but no decay occurred on coated, treated samples. Decay fungi were isolated from treated and non-treated coated arms, but isolation frequency was greater for non-treated materials. Coating thickness declined on both treated and non-treated materials, but the effects were greater on non-treated samples. Termites did not attack treated samples with or without coating, but destroyed untreated, non-coated samples and penetrated the polyurea coating to destroy untreated and borate dipped Douglas-fir. Polyurea coatings provided limited protection for non-treated wood. [ABSTRACT FROM AUTHOR]

The decay resistance of Palmyra palm wood (Borassus flabellifer), also referred to as sugar palm, was assessed in laboratory soil block tests against Oligoporus placenta, Gloeophyllum trabeum, Irpex lacteus, and Trametes versicolor as well as in a non-sterile soil burial test designed to encourage soft rot attack. Mass losses on pine control blocks were consistent with aggressive decay conditions for all but those exposed to Irpex lacteus, while mass losses for palm wood blocks exposed to the same fungi ranged from 0,46% to 10,6%. The magnitude of mass losses would categorize palm wood as resistant to highly decay resistant, suggesting that these materials might perform well in exterior above ground applications. Mass losses were weakly correlated with density suggesting that selection of denser wood will result in better performing materials in these applications. Field tests to confirm these results are encouraged. [ABSTRACT FROM AUTHOR]

• Evaluated effects of two brown rot fungi (Gloeophyllum trabeum and Rhodonia placenta) on performance of laterally loaded connections. • T-shaped connection assemblies modelling floor-to-wall connections in buildings were inoculated with fungi for up to 40 weeks. • Evaluated capacity, stiffness, energy dissipation, and ductility of connection assemblies through quasi-static cyclic connection tests. • Load carrying capacity and energy dissipating capacity were the most adversely affected of all the parameters evaluated. The effects of brown rot decay fungi on mechanical properties of CLT connection assemblies were investigated. CLT connections evaluated were assembled with code approved angle bracket connectors and modelled as floor-to-wall systems in mass timber buildings. Physical changes, mass loss and quasi-static cyclic tests were used to assess the performance of connection assemblies up to 40 weeks after fungal inoculation. Peak load, stiffness, energy dissipation and ductility of connections were characterized based on force–displacement data generated from the destructive test of connections. Assemblies experienced up to 57 % loss in load carrying capacity and 90 % loss in energy dissipating capacity of the connections after 40 weeks of fungal exposure. Connection stiffness was only slightly impacted over this period but wetting and redrying caused significant degradation of connection ductility. [ABSTRACT FROM AUTHOR]