Research Articles

Bamboo has gained increasing recognition as a sustainable structural material; however, the development of reliable connection systems remains a critical challenge for its broader application in construction. This study investigated a tensile connection for bamboo culms based on the principles of internal expansion and lateral friction while addressing the material’s inherent dimensional heterogeneity. The system was designed to facilitate installation, reduce costs, and require only minimal skilled labor, thereby improving the technical and practical feasibility of bamboo construction. An experimental program was conducted to evaluate the structural performance of the connection under tensile loading. The results demonstrated consistent mechanical behavior and significant load-bearing capacity, confirming the effectiveness of the internal expansion mechanism in accommodating geometric variability along the culm. Three main groups were tested, differing in the additives incorporated into the wood expander: sandpaper and polyurethane resin. The configuration incorporating polyurethane resin achieved the highest average ultimate tensile load (4.47 kN). The findings indicate that the proposed connection has strong structural potential and may contribute to the development of more reliable, scalable, and sustainable bamboo construction systems.

Although much is known about the properties of fiberboard and its constituents as a composite material, their dependency on morphological properties of the fibers within remains relatively unstudied. Regardless of the exact defibration method used on wood, a certain range of fiber aspect ratios are produced. The influence of aspect ratio distribution on fiberboard performance has been studied in conjunction with its dependence on hardwood/softwood content. Fiber samples with a range of hardwood content were imaged using a digital microscope and measured using image analysis. Thin fiberboard made from the sampled wood fiber was subjected to a variety of performance tests. Testing of fiberboard was done according to ASTM Standard D1037-12 (2020). No significant difference in flexural performance was found between the samples, with strain at break being the only exception. It is concluded that while longer, softwood fibers may have more favorable properties in standard applications of fiberboard, shorter, hardwood fibers have comparable mechanical properties when made into thin fiberboard while exhibiting significantly higher performance in internal bonding and water resistance.