Ответьте на вопросы к тексту.

1. What causes dimensional changes of concrete?

2. What does a deformation cause in an elastic material?

3. What does elastic strain result in?

4. How does creep depend on temperature?

5. How can the effects of shrinkage be reduced?

6. Does concrete have a high or low value of elastic modulus?

7. When may concrete be useful as a tie?

8. What reduces the value of the elastic modulus of the concrete?

Грамматические упражнения

Упражнение 1. Найдите в тексте сложноподчинённые предложения. Выделите в них главное и придаточное предложение.

Упражнение 2. Найдите в тексте существительные, образованные с помощью суффиксов - ion, - ment. От каких глаголов они образованы?

Лексические упражнения

Упражнение 1. а) Переведите на русский язык приведенные ниже существительные:

joint, variation, limit, deflection, elastic modulus, extension, tie,

прилагательные и наречия:

long, term, completely, over time, successful, dimensional, double, common, elastic,

служебные слова и обороты:

among, always, also, due to, only,

глаголы:

prestress, prevent, reach, continue, require.

b) Если Вы не знаете слово, найдите его в словаре. Выпишите из словаря то значение слова, в котором оно использовано в тексте.

Упражнение 2. Найдите перевод слов списка А в списке В.

Упражнение 3. Напишите предложения с каждым из перечисленных ниже слов:

reason - reasonable - reasonably

vary - various - variation

Урок 1.8 Фонетическое задание

Прочитайте транскрипцию в списке A, соотнесите её с соответствующим словом из списка B и переведите слово на русский язык. Учтите, что не все слова списка В даны в списке А.

A

[q'prPksImIt]; [dI'strOI]; ['kwIklI]; [geIn]; [In'SVq]; [rI'kwaIq]; [sq'fISqnt]; ["hPrI'zPntl]; ['vWtIkql]; [sI'ment]; ['sWfIs]; ['fWDq]; [tWm]; ['ADq]

B

Текст A

CONCRETE

PART II

Concrete cannot be placed during very cold weather because freezing water will destroy a concrete which has set partly. An approximate limit is that no wet concrete, after it is placed in its final position, should be at a temperature less than 5°C or 40°F. Even then insulation of the concrete will be necessary and the curing period, which is required to gain strength, will be long. In hot weather the problem during placement is to prevent a premature set and, after placement, in order to ensure a proper cure. The concrete must not dry out too fast because this may cause cracking.

One of the principal disadvantages of the use of cast-in-place concrete is the time that is required before the removal of the formwork. This period of time is necessary so as to allow the concrete to gain sufficient strength before it has to support itself; therefore the period before the removal of formwork must be longer for horizontal elements, such as beams and slabs, than for vertical elements, such as columns. Because of the cost of the formwork and in order to allow as rapid re-use as possible, cements which gain strength quickly are preferred by contractors. However, these cements produce such heat after they set that they may cause thermal cracking. In addition, the high temperature at which curing takes place leads to losses in the long term properties of the concrete. Slag cements and other low heat cements are better from this point of view. The formwork to beams and slabs is usually removed after a reasonable period of time but the props remain for a further period.

Typical minimum periods before removal of formwork for concrete with a surface temperature of 16°C (60°F) are from 9 hours to 15 days.

Notes:

freezing water замерзающая вода

premature adj. преждевременный

prop n. стойка

slag n. шлак