F. 2. Translate the text ALUMINIUM using a dictionary

TEXTS FOR READING

F. 1. Read the text and then render it in Russian

Bricks as a structural material were known many thousand years ago and are used as a substitute for other materials found in natural state. Bricks are hard and easily fastened together with the help of mortar which makes them suitable for construction purposes.

A brick building is strong, durable and weather resistant. It has, however, certain disadvantages. First, its foundation requires greater durability and takes up a much larger space than that of a wooden structure and is consequently more expensive. Second, the process of constructing a brick building is very slow and requires much skilled labour on the site. Such limitations of bricks led to the development of steel frame technique which allows an easy assembly of structural parts and makes possible the use of new materials.

Notes: steel frame technique технология стальных конструкций

substitute заместитель, заменитель

F. 2. Translate the text ALUMINIUM using a dictionary

Aluminium is the typical metal in the third group in the periodic classification of the elements. It has a white colour, does not corrode and is resistant to all inorganic acids except hydrochloric. Aluminium is best known light metal. Constituting 8 percent of the earth's crust, aluminium is the most abundant of the metals as well as one of the hardest to produce. It doesn't occur naturally in metallic form. Aluminium exists only in combination with other elements, primarily oxygen, with which it forms an extremely hard oxide known as alumina. Aluminium alloys can possess the strength of steel, though only a third the weight. Alloys of copper and aluminium which contain from 5 to 10 per cent of the latter are called aluminium bronzes. They have a fine yellow colour resembling gold.

In direct contact with a heat source, aluminium is an excellent conductor. Aluminium can be remelted over and over. Aluminium has a very low density. It is used in construction when a metal is required and weight is an important consideration. It is ductile, malleable and can be rolled. Its tensile strength is low in comparison with that of iron. Aluminium has replaced heavier copper in high voltage power line. The uses of aluminium are almost illimitable. It is used in aircraft, automobile, chemical and some other indusrtries.

F. 3. Read the text PRECAST OR IN-SITU CONCRETE? and speak on two types of concrete

The evolution of construction so as to build more rapidly involves a very large number of changes of technique. Perhaps the greatest change is in the proportions of constructional work on the site and in the factory, reducing the former to a minimum and increasing the latter to a maximum. This means the manufacture of larger and larger prefabricated units within the limits of transport. It is an easy matter to make the complete house in the factory, but it is not easy, in fact it is practically impossible to transport it to the site.

In this maximum factory work and minimum site work there is, of course, a much greater proportion of precast concrete and less in-situ concrete, while in the assembly of units dry methods are increasingly employed in preference to the traditional wet methods. But it may be questioned whether even now, dry methods of assembly are sufficiently employed and whether there is not still too much in-situ concrete work which cannot contribute so much to speedy construction as the employment of precast units.

So often when a building is erected by a prefabricated system with large units transported from the factory and quickly assembled the foundations and ground floor are of in-situ concrete. In many cases it probably takes as long to prepare the ground for concrete as to erect the skeleton of the building. Is it not possible more often to use precast units for the ground floor, and to employ a system by which the building is lifted on piers so making the use of site concrete unnecessary?

In buildings where a good deal of accommodation is provided below ground in a series of basements, or in a very high building, a good deal of site concrete work is necessary, but in buildings of a lighter type all above ground there would be advantages in speed by lifting them off the ground with a few supporting piers at intervals. In that way precast units could always be used for the ground floor, and thus make an important contribution to a dry building.

What is necessary in all building today, if the greatest speed is to be obtained, is to reduce wet methods on the site to a minimum and to aim at a maximum of dry assembly.