Building materials: advantages and disadvantages, Appunti di Inglese

Scarica Building materials: advantages and disadvantages e più Appunti in PDF di Inglese solo su Docsity! Building Materials Building materials can be divided into two main groups: natural and man-made. NATURAL MATERIALS: stone and timber. (Used by man since ancient times). MAN-MADE MATERIALS: bricks, cement, concrete, steel, glass, metal and more modern materials including plastic and synthetics. Stone ADVANTAGES: • Timeless, unique appearance • Design capabilities of through-body color material • Perceived value • Durable countertops and floors (granite) • May be re-polished if scratched • Natural stone has a very pleasing and natural aesthetic impact bringing one close to nature. • Natural Stone is an eco-friendly material. • Natural stones like granite and slate are a very strong and impervious material. DISADVANTAGES: • Ongoing re-sealing program is required • Limited chemical and stain resistance • Higher installation costs than ceramic tile • Product received seldom looks like the sample • Natural stone is quarried from natural quarries and other natural resources. Each quarry has its own unique chemical composition of stone and design of natural grains. Hence the stone flooring that is used for a certain space should be from the same quarry. 8 • Most of the natural stones are highly porous and absorb the stain marks very easily. Such natural materials have to be sealed properly and resins must be used to close all the pores of the stone. • Some stones are soft , brittle and very susceptible to chipping, developing cracks and breaking.Stones like Italian marble , onyx and travertine develop cracks very easily .After they are cut into slabs they are filled with resins to make the material strong and to seal all the cracks. • Laying of stones like marble and Italian is a time consuming process. After laying they have to polish several times by different grades of stone. Such natural stones flooring require regular maintenance over the years and have to be polished periodically. Timber ADVANTAGES: Timber is a versatile material. Excellent insulator: houses they are built out of bricks also known to have outstanding insulating properties, but timber manages to surpass them Timber is an elastic material: At the opposite of brick or concrete walls, timber walls don’t need to be very thick. A 20m timber wall for example, is strong enough to protect the internal space against the winter cold, in conjunction with a proper treatment Easy and fast to build: a timber construction can be build very easy and fast in contrast to a common brick or concrete construction Sustainable: timber is a renewable resource Reusable: timber can be used more than once. It is easy to recycle Price: to build a timber house or a timber construction is cheaper than any other common procedure which has the same requirements or sizes. Weight: timber is very light Strength: Timber framings are strong in real structural terms Esthetic appeal: timber is a beautiful material for both internal and external appearance. DISADVANTAGES: 8 DISADVANTAGES: • Compared to other binding materials, the tensile strength of concrete is relatively low. • Concrete is less ductile. • The weight of compared is high compared to its strength. • Concrete may contains soluble salts. Soluble salts cause efflorescence. Steel ADVANTAGES: Strength & Durability Structural steel components are lighter and stronger than weight-bearing wood or concrete products. A typical weight-bearing steel fabrication is 30% to 50% lighter than a wooden equivalent. This makes steel frame construction far stronger and more durable than traditional wood framed alternatives. Easy Fabrication In Different Sizes Steel studs are available in a variety of sizes and can be fabricated order. This means they can be customised to bear specific loads in buildings of all different types and sizes. Fire Resistance Steel frame constructions are highly resistant to fire, reducing the fire risk to a building and retarding the spread of a fire should one occur. Special flame retardant coatings act to increase this property of structural steel. Pest & Insect Resistant Structural steel components are immune to the degrading effects of burrowing insects and mammals – which can cause a problem for wooden framework unless adequately treated. Moisture & Weather Resistance Structural steel can have good moisture resistant properties, depending on its carbon content. Hot zinc coating and extra powder treatments for enhanced rust resistance will make a structural steel component even more immune to the effects of water – an important consideration for components exposed to the weather. DISADVANTAGES: 8 Steel frame constructions do have a couple of disadvantages, the most regularly cited being: Thermal Conductivity Steel is not known for its warmth, due to its high efficiency in conducting heat. The insulation value of walls can be reduced by as much as half when heat is transferred away through steel studs, which is not good news for energy retention in a building. Where steel frame construction is used, insulation measures need to be put in place to counteract the thermal conductivity of steel. Reduced Flexibility On Site One of the benefits of using wooden structural components is the ability to adjust them on site. A component can be cut down to size, nails hammered in to strengthen the join and so on. This obviously can’t happen with steel. The measurements of steel need to be precisely calculated in advance, because a steel fabrication is delivered to site in its final form, ready to be slotted into the building. This is of course one of the big advantages of steel, but if the fabrication has resulted in an inaccurate component for whatever reason, the project may be held up while the framework is sent back to the workshop for adjustment. You can avoid this issue by working with a fabrication company such as GLW, where we take a consultative approach to accuracy and measurements from the very beginning, to avoid any unpleasant surprises on site. Supporting Structures Steel frame constructions rarely work on their own. They usually require drywall, sheathing, insulation and supplementary wooden components to bring a building together. In the opinion of some construction businesses, this longer construction time is an argument against steel frame constructions, although usually the time savings outweigh any adjustments that need to be made on site. Glass ADVANTAGES: Can be made in different sizes and objects Can be coloured or colourless Does not rust Waterproof DISADVANTAGES: 8 An expensive material Breaks easily Melts in high temperatures When broken, the pieces may be sharp Metal ADVANTAGES: • Copper is a good electrical conductor for wiring; it is not reactive so can be made into water pipes • Lead can be bent easily so is used to seal joints on roofs • Steel is strong for girders and scaffolding • Aluminium alloys are corrosion resistant DISADVANTAGES: • Iron and steel can rust, severely weakening the structure The exploitation of metal ores to extract metal causes pollution and uses up the Earth's limited resources Metals are more expensive than other materials such as concrete Plastic ADVANTAGES: economical easy to fabricate Do not rot or corrode in air or water Can be used as insulators as they do not conduct heat or electricity Relatively cheap and can be moulded into any shape Lighter than wood, metal or glass Can be made very strong DISADVANTAGES: not biodegradable raw material costs 8