预应力胶合木梁受压区层板胶合木受压性能试验

Performances of Glued-laminated Timber in the Compressive Zone of Prestressed Glulam Beams

为了选择适用于新型预应力胶合木梁受压区的层板胶合木,选取SPF(云杉—松—冷杉)、杨木、东北落叶松和桉木等木制材料,研究树种类别、树种组合、层板厚度和组坯方式等因素对层板胶合木受压性能的影响。采用自行提出的棱柱体胶合木试块,利用自行研制的对夹式引伸计,通过4批次17组102个层板胶合木试块的顺纹受压试验,研究了层板胶合木的弹性模量、顺纹抗压强度、受力特征及破坏形态。结果表明:杨木、东北落叶松和桉木的弹性模量及顺纹抗压强度均高于进口木材SPF,尤其是杨木和东北落叶松的受压性能明显好于其他木材;不同树种组合与单一树种试块的弹性模量及顺纹抗压强度数值接近,不同树种组合具有一定的可能性;虽然随着层板厚度的减小,试块的弹性模量及顺纹抗压强度都有一定的上升趋势,但层板厚度和组坯方式对受压性能的影响不大。

In order to choose the layer board glulam for applying to the compression zone of the new type prestressed glulam beams, we studied the tree species, tree combination, the thicknesses of laminates, and assemble pattern to show the effect on the compression performance of layer board glulam by choosing the SPF, Poplar, North-East Larix, and Eucalyptus. Based on the compression tests along the grain on the 4 batches with 17 groups prism glulam specimens, a total of 102 by using a new type of holder type displacement sensor, we studied the elastic modulus, compression strength parallel to grain, mechanics characteristic and failure mode of the layer board glulam. The elastic modulus and the compression strength parallel to grain of Poplar, North-East Larix and Eucalyptus are both higher than those of SPF, especially the com- pression performance of Poplar and North-East Larix is much better than that of others. The elastic modulus and the compression strength parallel to grain from different tree species combination are similar with the feasibility of different species. Though the elastic modulus and the compression strength parallel to grain have a certain increasing trend with the decreasing thicknesses of laminates, the thicknesses of laminates and assemble pattern have little effect on compressive behavior.