Creep Behavior of Borate-treated Strandboard: Effect of Zinc Borate Retention, Wood Species, and Load Level

Creep performance of zinc borate-treated strandboard from southern pine (Pinus taeda L.) and red oak (Quercus falcata) was investigated at 25°C temperature and 65% relative humidity. It was shown that the borate treatment had some signifi cant effect on creep defl ection of the test panels, and the effect varied with wood species. There was no signifi cant effect of creep loading on residual bending properties of treated strandboard under the stress levels used. The four element spring-dashpot creep model fi tted the creep data well. The predicted creep defl ection for a 10-year loading duration under both 15% and 40% stress levels met the National Design Specifi cation for Wood Construction despite of the noticeable borate treatment effect on creep. Future work is needed to study the creep behavior under combined mechanical and moisture loadings for treated structural panels.