结构用工程竹干湿循环老化耐久性试验研究

Experimental Study on Durability of Engineered Bamboo for Structural Use Under Dry-wet Cycles

工程竹耐久性对结构安全性具有重要影响,环境湿度变化是影响生物质材料耐久性的重要因素之一。通过干湿循环人工加速老化试验研究胶合竹、重组竹、花旗松试件物理力学性能变化,研究结果表明,随着循环次数的增加,3种试件质量均有所减小,其中重组竹试件降幅最大;胶合竹、花旗松试件顺纹抗压强度小幅度减小,重组竹试件顺纹抗压强度增大;3种试件抗弯强度均呈减小趋势;相比抗压性能,工程竹抗弯性能更易受湿度变化的影响。当工程竹结构应用于湿度变化较大的环境中时,需进行有针对性的防护,保证材料含水率稳定性。

The durability of engineered bamboo has an important impact on the safety performance of the structure. The change of environmental humidity is one of the most important factors that affect the durability of biomass materials. In this paper,the physical and mechanical properties of laminated bamboo,bamboo scrimber and Douglas fir after accelerated aging under dry-wet cycles. The results show that the quality of the three materials all decreased with the increase of the number of dry-wet cycles,and bamboo scrimber shows the largest decrease. The paralled-to-grain compressive strength of laminated bamboo and Douglas fir decreased slightly,while that of bamboo scrimber increased. The bending strength of the three materials all decreased,among which Douglas fir shows the largest drop. Compared with the compressive performance,the bending performance of engineered bamboo is more susceptible to the change of environmental humidity. When used in conditions with large humidity changes,protection is required to maintain the stability of moisture content.