Hydrothermal Aging Properties of Three Typical Bamboo Engineering Composites

Area of Science:

• Materials Science
• Wood Science
• Composite Materials

Background:

• Bamboo engineering composites are increasingly used in construction.
• Understanding their behavior in hot, humid environments is crucial for predicting service life.
• Hygroscopic properties and mechanical degradation impact material performance.

Purpose of the Study:

• To investigate the hygroscopic characteristics of bamboo scrimber (BS), bamboo bundle/wood laminated veneer lumber (BLVL), and bamboo laminated timber (BLT).
• To predict performance changes and service life of these composites in hot, humid conditions.
• To analyze the degradation of elastic modulus under hydrothermal aging.

Main Methods:

• Exposure of composites to three temperature conditions (23 °C, 63 °C, 100 °C).
• Application of hygroscopic thickness swelling model and Fick's second law for water absorption analysis.
• Hydrothermal aging tests to assess elastic modulus (MOE) degradation.

Main Results:

• Hygroscopic thickness swelling coefficient (K) and diffusion coefficient (D) followed the order BLT > BLVL > BS at 23 °C and 63 °C.
• Bamboo scrimber (BS) demonstrated optimal dimensional stability, followed by BLVL and BLT.
• Elastic modulus degradation showed a linear relationship with aging temperature; after 152h at 63 °C, MOE degraded by 44.33% (BS), 53.89% (BLVL), and 25.83% (BLT).

Conclusions:

• Bamboo engineering composites exhibit distinct hygroscopic behaviors and dimensional stability.
• Bamboo scrimber offers superior performance in hot, humid environments compared to BLVL and BLT.
• Hydrothermal aging significantly impacts the elastic modulus of these bamboo composites, with varying degrees of degradation.