timber- as a building material
TRANSCRIPT
Building Materials & Construction CE-2153
Timber-as Building materials
Nur-160518
Raihan-160521
Biswazid-160526
Hasan-160529
Asha-160530
Group No. 04Group Members
Forestry & Wood Technology Discipline, Khulna University, Khulna, Bangladesh
TIMBER
The wood which is suitable or fit for engineering construction or engineering purpose is called Timber
Timber is one of the primary materials of engineering construction from the very earlier time
Only from Exogenous trees, we get timber
Sources of Timber
Advantage of timberCan be easily handled and joinedTimber can be used for both load –bearing structure and non load bearing instrumentIt can easily converted to any shape and sizeThe wastage in timber construction is lessTimber has better insulating properties than other materialsDurability of timber can be very high if properly seasoned and preserveTimber construction is light in weight and strong and can be made economicalFor aesthetic & decorated appearance Easily available High energy efficiency
Characteristics of good timbersStrong, stiff, tough & durableFree from natural & artificial defectRadially sawnColor should be dark as it indicate strong & durable timberStructure should be uniformHave a good workability Density should be highHave a sweet smellshould have elasticity Should be resistant to compression Should be fire resist Should have law water permeability
Sawing of Tree LogMethods of Sawing:Ordinary or Plain sawing Radial or Rift sawingTangential sawingQuarter sawing
Seasoning • Fresh timber have about 30 to 40 percent of
sap or moisture. This moisture is very harmful for the life of timber
• It is essential to remove the sap by applying certain special methods• All such are collectively termed as seasoning
Seasoning
Water
ArtificialNatural
Kiln chemical Electric
Seasoning technique
Advantages of SeasoningIt has reduced weight Strong & durable
Resistance to decay and rot Take high polish
Easier to work with Last longer
Defects in Timber
Defect due to seasoning
Some other defects occurring in timber:
Defects due to conservation
Defects due to fungiDefects due to Insects Knots
Objects of timber preservationTo increase the life of timber structures
To make the timber structures durable
To protect the timber from the attack of destroying agents such as fungi, insects, etc.
Timber preservatives
The main timber preservatives are : Ascu treatment Coal tar Paint Cresote oil Chemical salts Zinc chloride is the most extensively used of this types.It is clean and odourless
Uses of timber• Building construction• House post construction• Construction of bridge and boat• Furniture & instrument • Railway slipper • Toys and engraving work• Formwork of cement concrete
Use of timber in construction• Beam• Trusses • Rafters• Doors frame and shutters• Windows frame and shutters• Stair cases• Poles• Piles• Columns
Common timber in Bangladesh
TeakGarjanGamariJarulShissoShirisMahoganyChapalish etc.
Summary From all of these slides, we have learned….
• Source of timber• Advantages of timber• Characteristics of good timber• Sawing methods of Log• Seasoning & seasoning technique • Defects of Timber• Preservation of timber• Use of timber• Use of Timber in construction • Common timber of Bangladesh
That’s all…..
Thank you