Wood as a Construction Material . It is the oldest natural resource used by man. It has always provided him with fuel, tools and protection. It is a natural polymer of organic origin . It is obtained from inside the trunk of the trees.
The most used wood in construction is pine, as it is the most abundant. Although numerous species of pine are used, they all have similar characteristics. They require additives to resist the attack of microorganisms and insects. The most common are pine , fir , poplar , cedar , cypress and yew woods , among others.
Summary
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- 1 Main applications of wood in construction
- 2 Classification
- 3 Factors involved in wood deterioration
- 4 Advantages of wooden constructions
- 5 Disadvantages of wooden constructions
- 6 Use in construction
- 1 Timber formwork
- 2 Parts of the formwork
- 3 Formwork requirements
- 7 Sources
Main applications of wood in construction
The properties of wood are highly variable, depending on its intrinsic (species), environmental and other factors, such as: moisture content and permanence of loads, it is also a non-homogeneous, anisotropic , and fuel material. Variations in volume due to changes in humidity are an important factor.
The term wood includes natural wood in logs or squares and those that we could call industrialized, such as: plywood (plywood), gluing (glud-laminated timber) and that of shavings or fibers joined by an adherent and compressed.
Classification
The wood used in construction is classified into different groups: soft , very soft , semi-hard , hard and very hard . This classification does not take into account its hardness in the strictest sense of the word, since many of the woods included in the softwood group are harder than others that are included in the latter group. The hardness, in this case, is a function of its specific weight .
The hardness of wood is the resistance that opposes the penetration of other bodies, such as nails, screws, scratches and wear, etc. It is both a physical and mechanical feature and has great importance within the technique of wood.
The hardwood and semihard : used in general carpentry and construction, civil, naval, hydraulic constructions, coachwork, lathing, sizes, sleepers, telephone and electrical posts, beams, columns, piles, etc.
As it is known, in Cuba there is no wood in abundance to carry out an increasing exploitation of this natural resource. There are more than 800 species of timber trees but not all of them can be used for construction purposes, given their own characteristics, despite this, large areas of forests are not available in the country.
Without taking into account the cays around the island, there are currently 1,300,000 ha of forest, which constitutes 20% of the national territory, and must reach at least 25%, for which it is necessary to repopulate more than 1 700,000 ha. therefore, an urgent reforestation plan is required.
Factors involved in wood deterioration
The deterioration of the wooden elements or constructions is associated with a group of triggers that are reflected in the table.
Factors that intervene in the deterioration of the wood.
Advantages of wooden constructions
The main advantages of wood constructions are:
- Easily obtained.
- Less expensive than stone or metal.
- It is easily carved, except the very hard ones.
- It has great resistance to compression, traction and shear considering its low weight.
- Poor conductor of heat and electricity.
Disadvantages of wooden constructions
- It is fuel.
- Hygrometric changes cause it to change in volume and resistance and as an organic material, it can decompose and be attacked and destroyed by living organisms; although these defects can currently be eliminated with specific treatments.
- Lack of homogeneity and isotropy .
It is of great importance to know the advantages and disadvantages of wood, since the study and knowledge of them derives from a better use and use of its true potential as a construction material and an important renewable resource.
Use in construction
It is varied, since it is used as a material for structures, carpentry and molds.
Timber formwork
Pine wood is used, although other woods that meet the conditions of resistance and economy suitable for this type of work can be used.
Formwork parts
- Decks: (part of the formwork in contact with the concrete) in slabs, walls, lateral faces of beams and columns.
- Bracing: the same sections as for the decking but without brushing.
- Joists, column frames, ribs of beams or architraves and low-wall walls.
- Beams, wall ribs and props.
- Wedges
Formwork requirements
- Situation (in alignment and height).
- Shape and dimensions (according to the project).
- It will be watertight, without cracks, gaps or other imperfections.
- The interior surface is perfectly clean and smooth or according to the final finish that the concrete will have.
- It is built in such a way that they can be partially removed without affecting the stability of the assembly.
