Эксперт по сдаче вступительных испытаний в ВУЗах
TEXT 1
MODERN BUILDING MATERIALS
Building material is any material which is used for a construction purpose. Many naturally occurring substances, such as clay, sand, wood and rocks, even twigs and leaves have been used to construct buildings. Apart from naturally occurring materials, many man-made products are in use, some more and some less synthetic.Natural building materials are those that are unprocessed or minimally processed by industry, such as lumber or glass. Extracted or synthetic materials are made in industrial settings after much human manipulations, such as plastics and petroleum based paints. Both have their uses.
Natural materials are generally used as they are found, except for being cleaned, cut, or processed in a simple way that does not use much energy. Natural materials include stone and biological materials.Mud, stone, and fibrous plants are the most basic building materials, aside from tents made of flexible materials such as cloth or skins. People all over the world have used these three materials together to create homes to suit their local weather conditions. In general stone is used as basic structural components in the buildings, while mud is used to fill in the space between, acting as a type of concrete and insulation.
Thereare two types of building stone—crushed stone and dimension stone.Stone structures have existed for as long as history can recall. It is the longest lasting building material available, and is usually readily available.Biological materials are substances that develop as part of a plant or animal. Common plantmaterials include wood and various fibers such as cotton. Animal materials include leather and fibers suchas wool.Wood is a valuable biological material because of its strength, toughness, and low density. Theseproperties make wood an excellent material for thousands of products, including houses, sailboats,furniture, baseball bats, and railroad ties.
Extracted materials are created through processes that expend a great deal of energy or alter themicrostructure of the substances used to make the materials. Extracted materials include ceramics, metalsand their alloys, plastics, rubber, and composite materials.
Ceramics include such everyday materials as brick, cement, glass, and porcelain. These materials aremade from mineral compounds called silicates, including clay, feldspar, silica, and talc.People have used such metals as copper, gold, iron, and silver for thousands of years to make variouspractical and decorative objects. Today, metals are important in all aspects of construction andmanufacturing.Plastics are synthetic materials made up primarily of long chains of molecules called polymers.
There are two basic types of plastics: (1) thermosetting plastics (usual called thermosets) and (2)thermoplastics.Rubber is made up of elastomers, polymers that stretch easily to several times their length and thenreturn to their original shape.Engineers may artificially combine various materials to create a new composite material. Manycomposite materials contain a large amount of one substance to which fibers, flakes, or layers of anothersubstance are added.
Task 1.Complete the sentences.
- Basic types of materials range from wood to ___.
- Natural materials, which include stoneand wood, are used much as they___.
- Certain types of stone are extremely strong and hard, and are therefore used as ___.
- Today, metals are important in all aspects of ___.
- People have used such metals as copper, gold, iron, and silver for thousands of years to make ___.
Task 2. Find in the text the English equivalents for the following word combinations:
- natural materials
- dimensionstone
- lowdensity
- crushed stone
- baseballbats
- industrial settings
Task 3.Choose the right word or word-combination:
- Natural materials, which include stone, wood, and ___ are used much as they occur in nature.
- a) alloys b) wool c) plastics
- Biological materials are substances that ___ as part of a plant or animal.
- a) are formed b) grew c) develop
- Wood is a valuable biological material because of its strength, toughness, and low___.
- a) stiffness b) density c) creep
- Plastics are synthetic materials made up primarily of ___ called polymers.
- a) long chains of molecules b) mineral compounds c) biological materials
- Engineers may artificially combine various materials to create a new composite material.
- a) primarily b) easily c) artificially
Task 4. Answer the questions:
1.What is building material?
- What types of building materials do you know?
- What basic building materials do you know?
- What is the difference between natural and extracted materials?
5.How are extracted materials created?
Task 5.Find the part of the text where it is said about natural materials. Translate it in writing.
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