Wood, derived from trees, is a versatile and widely used construction material. Trees feature a trunk surrounded by a protective layer of dead bark. Beneath this outer layer lies the living bark, followed by the cambium, and then the sapwood which transitions into heartwood as it matures. At the center of the trunk is the pith. The age of a tree can be discerned by examining its growth rings, which are concentric bands visible in the trunk's cross-section.
The structural integrity of the wood is influenced by its grain—elongated, tubular cells aligned with the trunk's length, allowing it to bear greater loads along the grain direction compared to perpendicular to the grains.
Wood is available in the form of large cylindrical logs and transported to mills where it is transformed into boards and slabs. Before being used in construction, wood is typically seasoned to reduce moisture content and enhance durability.
Wood is used as lumber or timber in construction and is integral to building various structural elements and fixtures including doors, windows, flooring, roofing, columns, beams, and stair railings. It is also used in making furniture and scaffolding. Beyond solid wood, it serves as a base material for manufacturing plywood, particleboard, and hardboard.
Trees, the source of wood, have a trunk enveloped by a shielding layer of dead bark.
Under the dead outer bark is living bark. Next is the cambium, then the thick sapwood, which becomes heartwood as it ages. The pith is at the core of the trunk.
The tree's age can be determined by counting the concentric bands called growth rings in a tree's trunk.
Elongated, tubular cells aligned with the trunk's length define the wood's grain. Wood can take a greater load in the direction of grains than in the direction perpendicular to the grains.
Wood is procured from trees in the form of long cylindrical logs, which are transported to the mills for cutting.
The logs are usually cut into boards and slabs in the mills and seasoned before use.
Wood, particularly in the form of lumber and timber, is one of the most familiar construction materials.
Doors, windows, flooring, columns, beams, and stair railings are constructed using wood.
Additionally, wood is used to manufacture plywood, particleboard, and hardboard.
繁體中文
