Vocabulary

ancient - древний

brick – кирпич

bricklayer - каменщик

burnt clay– обожженная глина

clay – глина

concrete – бетон

durable – прочный

handling– транспортировка

hardness - твердость

lb – pound (англ. фунт – 453,6 г)

mortar– известковый раствор

opposite- противоположный

purpose - цель

pads – рукавицы

sawdust– опилки

surface- поверхность

thumb – большой палец руки

to burn – гореть

to dry – сушить

to utilize – использовать

Exercises

1. Переведите текст на русский язык, используя словарь.

2. Найдите в тексте ответы на поставленные вопросы и запишите их:

1. What can you say about the history of brickwork?

2. What materials is brick made of?

3) Why brick-building has been popular for many hundreds of years?

4) What is the shape of a brick?

5) What is the brick’s weight?

3. Подберите русские эквиваленты к следующим английским терминам:

a) the shape and size of a brick 1.ширина кирпича

b)topreventskin2.с полным мастерством

c) the width of a brick 3. положить кирпич

d) with complete mastery 4. форма и размер кирпича

e) to place a brick 5. защитить кожу

4. Переведите следующие предложения на русский язык:

1) A brick can be made of burnt clay.

2) Brick-building has been popular for many hundreds years.

3) A “would-be” bricklayer must practice handling a brick until he has control it with complete mastery.

4) A bricklayer is able to place a brick into any desired position.

5) The bricklayer’s thumb and the fingers must be protected with leather pads.

5. Составьте предложение из данных слов:

A, is, described, a, unit, building, brick, as.

UNIT 7

TEXT

PRESTRESSED CONCRETE

Prestressed concrete is not a new material. Its successful use has been developed rapidly during the last two decades, chiefly because steel of a more suitable character has been produced.

Concrete is strong in compression but weak when used for tensile stresses.

If, therefore, we consider a beam made of plain concrete, and spanning a certain distance, it will at once be realized that the beam’s own weight will cause the beam to «sag» or bend. This sagging at once puts the lower edge of the beam in tension, and if the cross-sectional area is small, causes it to break, especially if the span is relatively large.

If, on the other hand, we use a beam of similar cross-section, but incorporate steel bars in the lower portion, the steel will resist the tensile stress derived from the sag of the beam, and thus assist in preventing it from breaking.

In prestressed concrete steel is not used as reinforcement, but as a means of producing a suitable compressive stress in the concrete. Therefore any beam (or member) made of prestressed concrete is permanently under compression, and is consequently devoid of cracks – under normal loading, or so long as the «elastic limit» is not exceeded.

Prestressed concrete is not only used for beams but is now employed extensively for columns, pipes, and cylindrical water-towers, storage tanks, etc.