The Study On Mechanical Properties And Durability Of Modified Fast-Growing Poplar Wood

The fast-growing Poplar, planted in north Jiangsu province, were modified with low molecule PF and ACQ-D. The short-term mechanical properties and creep performance of all kinds of samples were tested and analyzed in this paper before and after being aged by ultraviolet. The leach property of reagent in modified samples with ACQ-D was analyzed and summarized. The results showed:(1). The modulus of elasticity of modified samples with different concentration PF was put forward in the light of composites mechanical principle. The empirical equation could predict the modulus of rupture and longitudinal compressive strength better according to the correlation between modulus of rupture, along grain compressive strength and modulus of elasticity.(2). The single-factor anova results showed, the effect of modification with ACQ-D on bending mechanical performance could be neglectable, but compressive strength along the grain was obvious. The effect of ultraviolet on mechanical performance of modified samples was significant, but untreated samples was not.(3). The mechanical performance of untreated and treated Poplar samples with PF was tested and analyzed from a reliability point. The statistic results showed the strength accorded with normal school in this experiment.(4). The sorption characteristic of treated samples with ACQ-D was similar with that of the untreated. The sorption ratio of treated samples with PF was bigger than that of the untreated. The sensitivity of all kinds of samples to relative humidity descended, and the sorption ratio was near to 1 after being aged by ultraviolet.(5). The creep deformation resistance was improved at the same stress level when low concentration PF was adopted, the result was opposite as high concentration PF. The creep deformation was greater within the same period when the concentration of PF was higer. The creep deformation of samples was bigger than that of samples impregnated with ACQ-D, and the deformation developed quicker at higer stress level. At the same stress level, the deformation of modified samples with ACQ-D was bigger than that of the untreated.The creep deformation of all kinds of samples aged by ultraviolet was different from that of the unaged. The influence of ultraviolet on creep deformation was complicated. The deformation of untreated and treated samples with low concentration at all stress levels, and of the modified samples with ACQ-D and high concentration PF at low stress level, was little effected by ultraviolet. Whereas, the deformation of the samples, modified with ACQ-D and high concentration PF at high stress level, after being aged by ultraviolet, was less.The modifed samples with PF were supposed as ideal elastic materials, and the predicted values of elastic deformation were near to the actual data. A new model, by means of regress analyse that could predict the creep deformation, was established, and its accuracy could be accepted.(6). The results about field durability resistance showed, the field durability of PF samples was the most strongest, that of ACQ-D samples was less, that of UF samples was medium and that of untreated samples was most weakest. The reagent leach in modified samples with ACQ-D was studied in this paper. Exponential and power function could fit the reagent leach decline.