Construction Materials and Testing CE23 PDF

by: Engr. Jonathan Calibara Engr. Vera Karla Caingles by: Engr. Jonathan Calibara Engr. Vera Karla Caingles  A. timber Ø The wood suitable for construction of buildings or for other engineerin...

by: Engr. Jonathan Calibara Engr. Vera Karla Caingles by: Engr. Jonathan Calibara Engr. Vera Karla Caingles  A. timber Ø The wood suitable for construction of buildings or for other engineering purposes is called timber by: En r. V En gr. J ra g on at arla e ha K n Ca aing lib C ar a le s  A. timber Wood continues to be one of the chief building materials. It is used for structural framing (rough carpentry), trim, floors, walls, and cabinetry (finish carpentry and architectural woodwork). Relative to its weight, wood has high strength in compression, tension, and bending. It by: En r. V also has excellent impact En gr. J ra g on at arla e resistance. ha K n Ca aing lib C ar a le s  A. timber When wood is cut into pieces of specific thickness, width, and length, it is called lumber. Lumber products include rough framing members (at least 2″ thick), such as beams, headers, and posts; finished lumber, such as flooring, door and window trim, paneling, and moldings; and specialty items, such as decorative panels, carved doors, ornamental overlay designs, and turned balusters (stairrail posts). Lumber is classified as rough-sawn or surfaced to size. Rough-sawn lumber has been cut to size but not dressed or surfaced. Surfaced lumber has been dressed or finished to size by running it through a planer. The designation “S2S” is used for lumber dressed on two sides, by: and “S4S” for lumber that is surfaced or planed on all four sides. En r. V En gr. J ra g on at arla e ha K n Ca aing lib C ar a le s  A. timber Plywood is a wood product made of several layers of lumber arranged with the grain at right angles in each successive layer and bonded with an adhesive. An odd number of layers is used, so that the grain of the face and back are running in the same direction. The panels are usually 4′ × 8′ in size, and are available in finished thicknesses ranging from 1/8″ to over 1″. Because of its modular size and uniformity, plywood speeds construction and is considered an economical building material. Interior plywood is bonded with an adhesive that is water-resistant. It is used for cabinetry, rough flooring, and finished walls. Exterior or structural plywood is bonded with a waterproof adhesive. It is used for by: En r. V wall sheathing, finished walls, roof sheathing, and concrete forms. En gr. J ra g on at arla e ha K n Ca aing lib C ar a le s  A. timber Glu Laminated Timber The process of laminating (bonding layers of lumber together with adhesive) has made it possible to span larger distances and change traditional construction techniques.Wood beams, arches, and other members of nearly any size and shape can be fabricated. These laminated products are made of kiln-dried lumber and prepared for interior and exterior use. These beams are usually prefinished at the factory and to the job with protective wrapping. by: En r. V En gr. J ra g on at arla e ha K n Ca aing lib C ar a le s  A. timber Ø Uses and importance of timber: qUsed as posts, beams, lintels, doors and windows qUsed in floorings, roofing, ceilings, etc., qUsed in rafters , purlins, trusses etc., qUsed for interior decoration purposes qUsed for making furniture, sport goods, railway sleepers etc., by: En r. V En gr. J ra g on at arla e ha K n Ca aing lib C ar a le s  A. timber Ø Properties of timber: The quality of timber must be ensured before using it for a purpose. The quality can be ensured by investigating the properties of timber. Color – It should be uniform. Light color indicates weak timber. Odor – It should be pleasant when cut freshly. Soundness – A clear ringing sound when struck indicates the timber is good Texture – Texture of good timber is fine and even Grains – In good timber, grains are close Density – Timber having higher density have a thicker wall and stronger Hardness – Harder timbers are strong and durable Warping – Good timber do not warp under changing of environmental conditions by: En r. V En gr Toughness – Timber should be capable of resisting shock loads. J ra g on at arla e ha K n Ca aing lib C ar a le s  A. timber Ø Properties of timber: The quality of timber must be ensured before using it for a purpose. The quality can be ensured by investigating the properties of timber. Abrasion – Good timber do not deteriorate due to wear. This property should be looked into , if timber is to be used for flooring Strength – Timber should have high strength in bending, shear, and direct compression Modulus of Elasticity – Timber with higher modulus of elasticity are preferred in construction Specific Gravity – Variation of timber in specific gravity (0.3-0.9) is found. It depends on pores present inside timber. The specific gravity of this light by: material is less than that of water (