TEXT 1. BUILDING MATERIALS
Materials used for construction purposes possess different properties. They differ in durability, strength, weight, fire- and decay-resistance and, naturally, cost.
Wood, timber, brick, stone, concrete, metals, and plastics belong to the most сommonly used building materials nowadays. In most cases it is important that they should be hard, durable, fire-resistant an easily fastened together. They all have their advantages and disadvantages that are taken into account when designing a structure.
Wood belongs to naturally growing materials. It is known to be the oldest construction material and is still widely used for different purposes. Wood is popular since it has low weight and is easy to work. Besides, it grows naturally and is cheap. But its usage is limited because of its disadvantages: it easily burns and decays. As to stone, it also belongs to the oldest building materials. Among its advantages there are strength, high heat insulation and fire-resistance.
As to stone it also belongs to one of the oldest building materials used by men. It is characteristic of many properties. Among its advantages there are mechanical strength, high heat and sound insulation and fire-resistance.
Brick belongs to artificial construction materials. It has been used in many countries and in different climates. In modern times bricks vary widely with the method of production and temperature of burning.
Concrete is known to be one of the most popular building materials. It is produced by mixing cement, gravel, water, and sand in the proper amounts.
Steel has come into general use with the development of industry. Its manufacture requires special equipment and skilled labour.
Plastics combine all the fine characteristics of a building material with good insulating properties. It is no wonder that the architects and engineers have turned to them to add beauty to modern homes and offices.
All building materials are divided into three main groups:
1) Main building materials such as rocks and artificial stones, timber and metals.
2) Binding materials such as lime, gypsum and cement.
3) Secondary or auxiliary materials which are used for the interior parts of the buildings.
We use many building materials for bearing structures. Binding materials are used for making artificial stone and for joining different planes. For the interior finish of the building we use secondary materials.
Natural building materials are: stone, sand, lime and timber. Cement clay products and concrete are examples of artificial building materials.
3. К каждой данной паре слов вспомните русское слово с тем же корнем, что и английское (работа в парах):
4. Какие из данных слов являются а) существительные б) прилагательные? Почему? (работа в парах)
mixer, various, advantageous, gravel, purpose, art, artificial, stone, resistant, resistance, durability, durable, disadvantage, property
5. Какие свойства строительных материалов могут иметь преимущества, а какие могут иметь недостатки? (работа в парах)
high cost fire-resistance non-fire-resistance
low resistance low cost high strength
high weight durability corrosion-resistance
heavy weight hardness softness