Wood Handbook: Basic Information on Wood as a Material of Construction with Data for Its Use in Design and SpecificationU.S. Government Printing Office, 1955 - 528 páginas |
Términos y frases comunes
air-dry applied Baldcypress basic stress beam bending boards bolt cedar coating column compression members connector construction creosote cross section decay diameter Douglas-fir eastern eastern hemlock eastern white pine effect F FIGURE face factor fiber finish flanges flooring formula glue glued growth ring hardwoods heartwood heat hemlock illus impregnated inches thick increase insulation joints joists knots laminated length less load lumber manufactured maple material moderately modulus of elasticity moisture content nails paint panels parallel to grain penetration pentachlorophenol perpendicular piece plies plywood poles pounds preservative Processed redcedar redwood resin resistance sapwood seasoned shear shear stress shrinkage side softwoods southern yellow pine species specific gravity spruce stain standard strength properties strength ratio structural surface temperature tension tests timber treated treatment trees U. S. Forest Prod usually values veneer weight western western redcedar width Wood-Preservers zinc chloride
Pasajes populares
Página 134 - Moisture affects the strength of structural timbers both directly and indirectly. The direct effect of loss of moisture is the stiffening and strengthening of the wood fibers. This increase in strength, however, is accompanied by checking, splitting, warping and twisting; as a consequence, some of the strength due to drying is lost.
Página 130 - Surfaced and matched; that is, surfaced one or two sides and tongued and grooved on the edges. The match may be center or standard.
Página 485 - ... tangential — strictly, coincident with a tangent at the circumference of a tree or log, or parallel to such a tangent. In practice, however, it often means roughly coincident with a growth ring. A tangential section is a longitudinal section through a tree or limb perpendicular to a radius. Flat-grained lumber is sawed tangentially.
Página 478 - ... is more often used. Coarse-grained wood: Wood with wide and conspicuous annual rings; that is, rings in which there is considerable difference between springwood and summerwood. The term is sometimes used to designate wood with large pores, such as oak, ash, chestnut, and walnut, but in this sense the term "coarse textured
Página 481 - Factory and shop lumber: Lumber intended to be cut up for use in further manufacture. It is graded on the basis of the percentage of the area which will produce a limited number of cuttings of a specified, or of a given minimum, size and quality.
Página 486 - Weathering. The mechanical or chemical disintegration and discoloration of the surface of wood that is caused by exposure to light, the action of dust and sand carried by winds, and the alternate shrinking and swelling of the surface fibers that come with the continual variation in moisture content brought by changes in the weather.
Página 482 - Pitch streak. — A well-defined accumulation of pitch in a more or less regular streak in the wood of certain conifers. Pith.
Página 486 - Wane. — Bark or lack of wood from any cause on edge or corner of a piece. Warp. — Any variation from a true or plane surface. Warp includes bow, crook, cup, and twist, or any combination thereof.
Página 252 - The effective cross-sectional area of the member shall be computed by subtracting from the gross cross-sectional area, the area of all laminations containing butt joints at a single cross-section. In addition, laminations adjoining...
Página 274 - Interior type is expected to retain its form and practically all of its strength when occasionally subjected to a thorough wetting and subsequent normal drying. It is commonly bonded with soybean glue or with an extended resin glue of the phenol type. Exterior-type plywood is expected to retain its form and strength when repeatedly wet and dried and otherwise subjected to the elements and to be suitable for permanent exterior use.