The Mechanical Properties Of Bamboo Reinforced Poplar Laminated Veneer Lumber(LVL) After Hot-moisture Treatment

In this dissertation, we made 2 kinds of bamboo reinforced poplar Laminated Veneer Lumber (LVL), using bamboo curtain as the strengthened materials. There are 1 layer bamboo curtain in the second floor and the reciprocal second floor respectively for structure B, there is a layer bamboo curtain in the middle of floors for structure C.The mechanical properties of bamboo reinforced poplar LVL in normal condition and after hot-moisture treatments were studied.Through a comparing study on dynamic and static Modulus of Rupture (MOR) of bamboo reinforced poplar LVL in normal condition, we found that the trends of MOR enhance while the loading rate increases; the loading rate is between 1 mm/min and 150 mm/min, the MOR of B is larger than C; while the loading rate is more than 150 mm/min, the MOR of C is larger than B; the dynamic MOR of B and C are larger than the static MOR respectively and the dynamic MOR of B is larger than C obviously.It was found that in normal condition, the bamboo contribution ratio of B and C to MOE is similar, at about 29%, but the bamboo contribution ratios of B are larger than C to MOR and Impact Toughness.Through 3 different kinds of hot-moisture treatments, there were some conclusions as follows:After the 10 days treatment in which the temperature is 40℃ and the Relative Humidity is 90%, the mechanical properties of all kinds of LVL decreased obviously. After the treatment, the MOE of all kinds of bamboo reinforced poplar LVL decreased about 30% and poplar LVL decreased 22.2%, the MOR of all kinds of bamboo reinforced poplar LVL decreased about 40.8% while the MOR of poplar LVL decreased 33.6%, the Impact Toughness of all kinds of bamboo reinforced poplar LVL decreased about 10.6% while the Impact Toughness of poplar LVL decreased 11.7%. As a whole, the attenuation rate of bamboo reinforced poplar LVL was larger than poplar LVL.