Text 13 Cement

Words and word-combinations to be remembered:

to fulfill – виконувати, здійснювати

to a great extent – значною мірою

to obtain – одержувати, здобувати

finesse – дрібнозернистий

to grind – розтирати, молоти

dam – гребля, дамба

to retain – утримувати, підтримувати

advantageous – сприятливий, вигідний

selection – вибір, відбір

to ensure – забезпечувати, гарантувати

aggregate – агрегат

mix – суміш

Read and translate the text:

Cement

The requirements to be fulfilled by concrete vary to a great extent. One of the essential properties of concrete is its compressive strength. From the time of its first production more than a century ago there was a steady and gradual improvement in the compressive strength of Portland cement until the beginning of the war. With the cements now available much higher strengths can be obtained than some 40 or 50 years ago. The increase in strength is partly due to the increased fineness to which modern cements are ground.

Cement develops heat during hydration. This is of considerable importance in certain types of concrete construction, particularly in structures of large volume, such as dams, massive retaining walls and the like. A very high rate of heat development is advantageous in work done in cold weather, so as to protect the fresh concrete from the effect of low temperatures.

It should be noted, of course, that not all properties desired can be obtained in any one cement.

Selection of the cement alone does not ensure concrete with the properties desired, which depend also on the choice of aggregates and mixes, the control of the quantity of water added to the mix, and on a series of other factors

Exercise 1.

What’s the English for:

виконувати утримувати

значною мірою сприятливий

одержувати вибір

дрібнозернистий забезпечувати

розтирати агрегат

дамба, гребля суміш

Exercise 2.

Complete the following sentences according to the text:

1. One of the essential properties of concrete is … .

2. The increase in strength is partly due to … .

3. Cement develops … during hydration.

4. A very high rate of … is advantageous in work done in cold weather, so as to protect the fresh concrete from … .

5. The properties of cement depend on … .

Exercise 3.

Answer the questions in English:

1. What is one of the essential properties of concrete?

2. When was a steady and gradual improvement in the compressive strength of Portland cement?

3. What is the increase in strength due to?

4. What does cement develop during hydration?

5. Why is it so important in concrete construction?

6. What do the properties of cement depend on?