Materials to be used for structural purposes should meet several requirements depending upon their practical uses. In most cases it is important that they should be hard, durable, fire-resistant and easily fastened together. We determine whether a material is good for building purposes judging by its qualities. At all times it was important to know how the most commonly used materials – steel, stone, wood and brick – differed in hardness, durability and fire resistance.
Steel. We say that we live in the age of steel, and indeed there is no industry which does not use it. As structural material steel has come into general use with the development of industry, its manufacture requiring special equipment and skilled labour. Steel gas largely displaced wood and bricks as basic materials in construction. Its technique has combined the best principles of the older methods.
Speaking of steel we should realize how many different properties it can possess. Its varying properties depend on the nature of the tempering – that is, on the way in which the steel has been allowed to cool, and partly on the substances the iron has been combined with.
Concrete. Concrete is one of the most important materials. We live and work in concrete structures, drink water which is brought to our houses through concrete pipes. Concrete is a mixture of cement, sand and crushed stone, made into a paste with water. It forms a hard durable mass and is largely used for the foundations and walls of houses, and for structures under water.
Stone. Stone belongs to one of the oldest building materials used by man. Primitive stone structures imitating caves where the primitive man found shelter were the earliest types of human dwellings. Stone has many properties owing to which it is widely used for building purposes. These properties are mechanical strength, compactness, sound and heat insulation and fire-resistance. Stone is widely used for foundations, walls and steps of buildings, for supports of piers and bridges, and for finishing and decorating all sorts of structures.
Выучите слова.
determine - определять
purpose – цель, назначение
require – требовать
resist – оказывать сопротивление
resistance - сопротивление
equipment - оборудование
whether - ли
hardness - твёрдость
judging by – судя по
concrete - бетон
range – ряд, диапазон
property - свойство
vary - различаться
that is – т. е.
substance - вещество
cool – охлаждать, прохладный
development - развитие
quality – качество, свойство
structural – конструктивный, строительный
to meet the requirements – отвечать требованиям
depending (upon) – в зависимости от
durable – прочный, долговечный
durability – долговечность, прочность
manufacture – производить, производство
realize – осознавать, понимать
differ (in) – различаться (в, по)
for instance (for example) – например
Задание 1. Прочитайте текст еще раз, отыскивая ответы на следующие вопросы.
1. What properties of materials are important for building purposes?
2. Do building materials differ in properties?
3. In what properties do they differ?
4. When did steel come into use?
5. Does steel manufacture require special equipment?
6. What materials did steel displace in construction?
7. Does steel possess many different properties?
8. What is one of the most important building materials used at present?
9. Where do we deal with concrete?
10. What is concrete?
11. What is it largely used for?
12. Is stone an old building material?
13. What was stone used for by a primitive man?
14. Does stone have many properties?
15. What are the properties of stone?
16. What is stone used for?
Text B. Building Materials.
Materials used for structural purposes are called building materials.
The main building materials are timber, stone, brick, concrete, steel, light metals, glass and plastics.
Timber is unique among the materials of construction. It will be available when the earth’s capital deposits of iron, coal, clay, and the rest have been consumed.
The buildings made of stone or brick are durable and fireproof, they have poor heat conductivity.
Concrete made with natural hydraulic binders was used in antiquity, particularly by the Romans. After the decline of the Roman Empire the art of making concrete has been forgotten, and the revival came much later.
Portland cement was produced more than a century ago. From the time of its first production there was a steady and gradual improvement in its compressive strength.
Reinforced concrete is hardly 100 years old, but its practical application in building began only 90 years ago. Today reinforced concrete is used in all civilized countries as one of the most important building materials. One of the essential properties of concrete is its compressive strength.
Задание 2. Сравните формы сказуемого в следующих предложениях и переведите их.
1.We use many new building materials. 2. Many new building materials are used in construction. 3. Concrete was used by the Romans. 4. Builders use cement to make concrete. 5. Cement is widely used for making concrete. 6. Portland cement was produced more than a century ago. 7. Today reinforced concrete is used in all countries. 8. Materials used for building purposes are called building materials.
Unit 5