Effect of low temperature on the mechanical properties of Pinus koraiensis and Populus ussuriensis timber

Pinus koraiensis and Populus ussuriensis timber were used to study the influence of environmental temperature( especially low temperature) on the mechanical properties of wood in this paper. The wood specimens of two species were conducted a series of wood quality tests at air-dried and wet conditions. Then the modulus of elasticity( MOE),modulus of rupture( MOR) and compression strength of heartwood and sapwood were obtained and analyzed at- 20 ℃,- 5 ℃,5 ℃,and 20 ℃ temperature. The results showed that temperature was one of the important factors affecting the MOE,MOR and compression strength of wood. As temperature decreased,these mechanical parameters of air-dried wood increased linearly,but for the nonlinearly increased wet wood,these parameters decreased from 20 ℃ to- 5 ℃,but increased fast from- 5 ℃ to- 20 ℃. The mechanical properties of wet wood were more sensitive to low temperature than that of air-dried wood,which of wet wood were about 67% higher at- 20 ℃ than that at 20 ℃,but the corresponding value of air-dried wood only increased about 15%.