Unit 2 Text a. TheMost Important and Widely Used Building Materials.

The designer must be able to select and adapt such materials of construction that will give the most effective result by the most economical means. In this choice of materials for any work of construction, the civil engineer must consider many factors. These factors include availability, cost, physical properties of materials and others.

Timber, steel and concrete vary in he properties desired by the engineer. Even steel, uniform as it appears, varies considerably in its microstructure. Concrete is even less uniform than many other materials.

Lime, gypsum and cement are the three materials most widely used in building construction for the purpose of binding together masonry units, such as stone, brick and as constituents of wall plaster. Cement is the most important component of concrete.

The most important building materials are now considered to be structural steel and concrete. Concrete may be considered an artificial conglomerate of crushed stone, gravel or similar inert material with a mortar. A mixture of sand, screenings or similar inert particles with cement and water which has the capacity of hardening into a rocklike mass is called mortar. The fundamental object in proportioning concrete or mortar mixes is the production of durable material of great strength, watertightness and other essential properties at minimum cost.

To attain this careful attention must be given to the selection of cement, aggregate, and water.

Выучите слова.

means - средство, способ

availability - наличие

property - свойство

timber - древесина, строевой лес

concrete - бетон

uniform - однородный

lime - известь

gypsum - гипс

cement - цемент

brick - кирпич

stone - камень

masonry - каменная кладка

unit - элемент, деталь, блок

wall plaster - стенная штукатурка

to consider - считать, полагать

mortar - раствор

mixture - смесь

durable - прочный, долговечный

aggregate - заполнитель

Text B. Brick.

Brick is one of the oldest artificial structural materials. Brick is an artificial stone made of clay. It is hardened by burning in the sun or in kiln. The clay is mixed with water by hand or a machine. The first brick ma­chine was driven by a horse and then it was driven by a steam engine.

Brickmaking in our days is a mechanized process. The molded bricks are burnt and dried in kilns.

Brick is less expensive than stone but more expensive than concrete. Brick is less durable than stone. There are ma­ny kinds of bricks, for example sand-lime brick, face brick, glazed bricks etc. But sand-lime brick is most popular. It is made of sand and a small admixture of lime. Silica brick is prepared under the tremendous pressure of about 100 tons.

This brick is very solid and has good moisture resistance. At present brick is widely used in the construction of foun­dations, walls, piers and arches of buildings and the structures of ducts, flues and chimneys of furnaces.

Notes:

molded brick – обычный формованный кирпич

sand-lime brick – силикатный кирпич

face brick – лицевой кирпич

glazed brick – глазурованый кирпич

flue – дымоход

Задание 1. Определите функцию инфинитива, переведите.

1. To test this device is our task. 2. Our task is to test this device. 3. Our engineers want to test this device. 4. The device to be tested is in our laboratory. 5. The engineers came to the laboratory to test this device.

Задание 2. Переведите предложения, обращая внимание на прилагательные.

1. Strength of materials is one of the most important subjects for a future engineer. 2. Concrete is less uniform than many other materials. 3. The most accurate method of measuring proportions is to weigh the required quantities of materials. 4. Portland cement has greater resistance to some chemicals. 5. The new houses are more comfortable than the old ones. 6. The sooner they finish the construction of the plant the better.