The Exploration Of Reinforcing Mechanics Property Of Laminated Veneer Lumber (LVL) With Twisted Bamboo Ties

This topic proposed one new research technique of wood and bamboo composite, in which we apply the pre-stressed from twisted bamboo ties into wood and bamboo composite. The experimental study included three parts: the manufacture research of bamboo ties; the research and choice of the method of twisting bamboo ties in reinforcement board; the manufacture method of wood and bamboo composite.The bamboo ties were manufactured by suppressing the softened bamboo with rolling-suppress machine. In the experiment we selected four kind of softening method of bamboo. According to the degree of fineness and the mechanics property of bamboo, we analyzed the influence of different softening method to the bamboo ties. The result indicated soaking bamboo in the water two days is the better softening method. This kind of bamboo ties had a better degree of fineness and a better mechanics performance.In the experiment we manufactured four kind of reinforcement board. The test result indicated the pre-stressed from the twisted single strand of bamboo ties remarkably reinforced the mechanics performance of composite material. The data contrast between the reinforcement board containing single strand of bamboo ties and the reinforcement board which contained bamboo not being twisted demonstrated that the contribution ratio of pre-stressed had respectively achieved to 7.46% and 11.11% in Modulus of Elasticity (MOE) and Modulus of Rupture (MOR) which confirmed applying pre-stressed into wood and bamboo composite may reinforce mechanics performance. Meanwhile, the result indicated whether the existence or not of bamboo ties didn't connect with the Shearing Rupture. In the experiment we established the mechanics model of twisted bamboo ties and analyzed it theoretically.In the experiment we manufactured five kind of LVL. The data analysis indicated: because of the reinforcement of bamboo ties, both MOE and MOR of LVL not containing bamboo ties were lower than the MOE and MOR of LVL containing bamboo ties respectively; when the LVL containing the same quantity bamboo ties, both MOE and MOR of the LVL containing twisted bamboo ties were higher, which proved the effectiveness of pre-stressed form the twisted single strand of bamboo ties was remarkable; with the quantity of bamboo ties increasing, the mechanics performance of the LVL containing twisted bamboo ties reinforced. The test result showed that whether the existence or not of bamboo ties or whether bamboo ties were twisted didn't connect with the Shearing Rupture and Impact Toughness of the LVL.