Wood physical and mechanical properties of rambai (Baccaurea motleyana), a tropical fruit tree species

Abstract

This study evaluated the physical and mechanical properties of rambai (Baccaurea motleyana) wood to assess its potential as a timber resource in multipurpose fruit-timber systems. Small clear specimens were prepared from the base, middle, and top section of three mature rambai trees (diameter at breast height 38-44 cm) grown in a private garden, and tested for physical and mechanical properties following the Deutsches Institut für Normung (DIN) standards. The results showed that rambai wood has Green Moisture Content (GMC) of 104.98±9.20%, decreasing significantly from the base toward the top of the stem. Apparent density at ~12% MC averaged 0.62±0.04 g/cm3 and did not differ significantly among axial positions of the stem. Shrinkage behaviour was typical of hardwoods, with tangential and radial shrinkage of about 5.9% and 3.8%, respectively, and a tangential–radial ratio of 1.59±0.28, indicating satisfactory dimensional stability. Mean mechanical properties across the whole stem were 9.52±1.49 GPa for MOE, 85.16±11.28 MPa for MOR, 51.69±5.69 MPa for compression parallel to grain. Impact bending strength and shear strength averaged 7.26±1.65 J/cm2 and 11.81±1.35 MPa, respectively. Overall, these values characterize B. motleyana as a medium grade hardwood with physical and mechanical properties compatible with potential usein furniture, interior joinery and light construction, while further studies on durability, workability and anatomical characteristics are needed to provide stronger support to its promotion as a lesser-known tropical wood resource from fruit-timber systems.