CMT

• Timber


  The wood suitable for construction of buildings or for other engineering purposes
• Timber


  • Used for structural framing, trim, floors, walls, and cabinetry
  • Relative to its weight, has high strength in compression, tension, and bending
  • Has excellent impact resistance
• Lumber


  Wood cut into pieces of specific thickness, width, and length
• Lumber products


  • 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
  • Specialty items, such as decorative panels, carved doors, ornamental overlay designs, and turned balusters (stairrail posts)
• Rough-sawn lumber


  Cut to size but not dressed or surfaced
• Surfaced lumber


  Dressed or finished to size by running it through a planer
• Plywood


  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
• Plywood


  • An odd number of layers is used, so that the grain of the face and back are running in the same direction
  • Panels are usually 4' x 8' in size, and are available in finished thicknesses ranging from 1/8" to over 1"
  • Speeds construction and is considered an economical building material
• Interior plywood


  Bonded with a water-resistant adhesive, used for cabinetry, rough flooring, and finished walls
• Exterior or structural plywood

  Bonded with a waterproof adhesive, used for wall sheathing, finished walls, roof sheathing, and concrete forms
• Glue Laminated Timber


  The process of laminating (bonding layers of lumber together with adhesive) to span larger distances and change traditional construction techniques
• Uses and importance of timber


  • Used as posts, beams, lintels, doors and windows
  • Used in floorings, roofing, ceilings, etc.
  • Used in rafters, purlins, trusses etc.
  • Used for interior decoration purposes
  • Used for making furniture, sport goods, railway sleepers etc.
• Properties of timber


  • Color - should be uniform, light color indicates weak timber
  • Odor - 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
  • Toughness - timber should be capable of resisting shock loads
  • Abrasion - good timber do not deteriorate due to wear
  • 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, depends on pores present inside timber
• Sand


  A granular material composed of finely divided rock and mineral particles, finer than gravel and coarser than silt
• The most common constituent of sand is silica (silicon dioxide, or SiO2), usually in the form of quartz
• Sand is a non-renewable resource over human timescales, and sand suitable for making concrete is in high demand
• Uses and importance of sand


  • Providing bulk, strength and stability to other materials such as asphalt, concrete, mortar, render, cement, and screed
  • Used as a base layer known as 'blinding', laid above a layer of hardcore to provide a clean, level and dry surface for construction works
  • Used in its raw form as a decorative material in landscaping
  • Used in liquid form to manufacture glass
  • Used for moulding metal casting
  • Used to make sandpaper
• Types of sand


  • Particle size: 0.6-2 mm (coarse sands), 0.2-0.6 mm (medium sands), 0.06-0.2 mm (fine sands)
  • Particle shape: Angular, subangular, rounded, flat, elongated
  • Texture: Rough, smooth, or polished
  • Composite soil types: Sandy gravel, gravelly sand, clayey composites, silty composites
  • Structure: Homogenous, inter-stratified, heterogeneous, or weathered
• Sources of sand


  • River Sand - obtained from large rivers, usually fine in size
  • Pit Sand - obtained from old stream beds, sharp and generally coarse
  • Sea Sand - obtained from beaches, usually good for most works if free from detrimental salts
• Properties of sand


  • The grains should be sharp, angular and coarse
  • The sand should be free from clay material and organic matters
  • The grains should be of durable minerals
  • It should be free from salts
  • The gradation of grains size should be such as that it will give minimum voids
  • It should be clean and free from coatings of clay and silt
  • It should not contain organic matter
  • It should be chemically inert
• Gravel


  A loose aggregation of rock fragments, classified by particle size range from granule- to boulder-sized fragments
• One cubic metre of gravel typically weighs about 1,800 kg (or a cubic yard weighs about 3,000 pounds)
• Uses and importance of gravel


  • Used for the manufacture of concrete, as well as for mixing with asphalt as part of road construction
  • Used as the base layer for roads before being covered with tarmac
  • Used to surface roadways, especially those in rural areas and in icy conditions
  • Used along with pebbles as a form of render known as pebbledash for external walls
  • Used in the filtration of water, acting as a natural filter
  • Used for landscaping applications, such as on driveways, walkways, or as a decorative filler over soil instead of grass
• Properties of gravel


  • It should be hard, strong and durable
  • It should be dense, clear and free from any coating
  • It should be free from injurious vegetable matters
  • It should not contain flaky (angular) and elongated pieces
  • It should not contain any material liable to attack steel reinforcement in case of reinforced concrete
• Rebar


  A steel bar or mesh of steel wires used in reinforced concrete and masonry structures to strengthen and hold the concrete in tension
• Rebar


  • The surface is often patterned to improve the quality of the bond with the concrete
  • Primary reinforcement is used to provide resistance to support design loads
  • Secondary reinforcement is used for durability and aesthetic purposes by providing localised resistance to limit cracking and temperature-induced stresses
  • Provides resistance to concentrated loads, spreading it through a wider area
  • Assists other steel bars in accommodating their loads by holding them in the correct position
• Uses and importance of rebars

  • Used as external steel tie bars to constrain and reinforce masonry structures, sometimes as a means of building conservation
  • Used in reinforced masonry, where some masonry blocks and bricks include voids to accommodate rebar to carry tensile loads, secured in place using grout
• Tensile strength


  The ultimate strength of the rebar is at least 10-15% more than the yield strength of the bar
• Reinforcing bars (rebars)


  • The surface of rebar is often patterned
• Primary reinforcement


  Used to provide resistance to support design loads
• Secondary reinforcement


  Used for durability and aesthetic purposes by providing localised resistance to limit cracking and temperature-induced stresses
• Rebars


  Provide resistance to concentrated loads, spreading it through a wider area<|>Assist other steel bars in accommodating their loads by holding them in the correct position
• Uses and importance of rebars

  • External steel tie bars to constrain and reinforce masonry structures, sometimes as a means of building conservation
  • Reinforced masonry: Some masonry blocks and bricks include voids to accommodate rebar to carry tensile loads
  • The rebar is secured in place using grout
• Properties of rebars


  • Tensile strength
  • Bond strength
  • Ductility
  • Weldability
  • Corrosion resistance
  • Fire resistance
• Mild Steel Bars


  The surface of the mild steel bars are plain and round in shape. They are available in various sizes of 6 mm to 50 mm. They are used in concrete for special purposes, such as dowels at expansion joints, where bars must slide in a metal or paper sleeve, for contraction joints in roads and runways, and for column spirals. They are easy to cut and bend without damage.
• Deformed Steel Bar


  Deformed steel bars have ribs, lugs and indentation on the surface of the bar, which reduces the major problem that is faced by mild steel bar due to slippage and good bonding is achieved between concrete and rebar. The tensile properties is higher compared to other rebars. These bars are produced in sections from 6 mm to 50 mm dia.
• Types of Deformed Bars

  • Thermo Mechanically Treated Bars
  • High Strength Deformed Bars
• Thermo Mechanically Treated Bars


  Hot treated bars that are high in strength used in reinforced cement concrete (RCC) work. It is the latest induction in the MS steel bars with superior properties such as strength, ductility, welding ability, bending ability and highest quality standards at international level.
• High strength deformed bars


  Cold twisted steel bars with lugs, ribs, projection or deformation on the surface. It the extensively and majorly used for reinforcement purposes in a construction. These bars are produced in sizes or sections from 4 mm to 50 mm in diameter.
• Other Types of Rebars

  • European Rebar
  • Carbon Steel Rebar
  • Epoxy-Coated Rebar
  • Galvanized Rebar
  • Glass-Fiber-Reinforced-Polymer
  • Stainless Steel Rebar