The effect of knot clusters on the bending properties of Korean pine (Pinus koraiensis) cross-laminated timber (CLT) was analyzed to increase the utilization of low-quality lumber. The laminae used to manufacture the CLT were classified into five groups, four major layer groups, and one minor layer group, by mechanical grade and knot area ratio (KAR) of the lamina. Out-of-plane bending tests were conducted on CLT made from each layer group. The modulus of elasticity (MOE) of the manufactured CLT was closely correlated with the MOE of each individual major axis lamina. In the case of the modulus of rupture (MOR) of the CLT, the KAR of the laminae used in the major axis layer was more significantly affected than the MOE. The main finding is that the lower fifth percentile MOR value of the CLT specimens with large knots (KAR > 0.5) was higher than the acceptable reference value of E3 grade CLT (ANSI/APA PRG 320) made from a similar lamina grade. Therefore, the use of low-quality lumber to manufacture CLT can be expanded under the condition of limitation of the greater KAR.

结簇对红松弯曲特性的影响）对交叉层压木材（CLT）进行了分析，以提高低质量木材的利用率。根据薄层的机械等级和结面积比（KAR），用于制造CLT的薄层被分为五组，四个主要层组和一个次要层组。在由每个层组制成的CLT上进行面外弯曲测试。制成的CLT的弹性模量（MOE）与每个单独的主轴层的MOE紧密相关。在CLT的断裂模量（MOR）的情况下，长轴层中使用的薄片的KAR比MOE受到更大的影响。主要发现是，大结节的CLT样品的下五分位数MOR值较低（KAR> 0。5）高于由类似薄板等级制成的E3级CLT（ANSI / APA PRG 320）的可接受参考值。因此，在更大的KAR限制的情况下，可以扩大使用劣质木材制造CLT的用途。