The knowledge of how to make durable concrete has been lost for centuries.

21. Fusion of Roman and North European traditions in construction was reflected in many ways.

22. Many structures made of concrete remain till nowadays thus proving the long life of buildings made of concrete.

23. Materials that are used for structural purposes should meet several requirements.

24. Concrete is referred to as one of the most important building materials.

25. Steel has come into general use with the development of industry

26. The architects and engineers have turned to plastics to add beauty to modern homes and offices.

27. We use many building materials for bearing structures.

28. Binding materials are used for making artificial stone and for joining different planes.

29. Timber is a name applied to the cut material derived from trees.

30. Timber used for building purposes is divided into two groups: softwoods and hardwoods

31. Timber cannot be used for either carpenters' or joiners' work immediately it has been felled because of the large amount of sap which it contains.

32. Stone has been used as a structural material since the earliest days.

33. In some places stone was used because of the scarcity of timber, but in other places stone was preferred because of its durability.

34. Sandstone is composed of grains of sand or quarts cemented together. The durability of sandstones depends very largely upon the cementing material.

35. These characteristics are possessed by all metals but the metals themselves differ from one another.

36. Cast iron is chiefly used in building for compressed members of construction, as the supporting members.

 

КОНТРОЛЬНАЯ РАБОТА N 2

1. Cement is the most essential material and the most important one for making concrete of high quality.

2. Cement is made of limestone and clay. It is burnt at high temperature and ground up into powder.

3. Depending on the kind and composition of the raw materials different types of cement are obtained.

4. Concrete is made by binding together particles of sand and gravel, stone or broken brick.

5. Cement starts hardening one hour after the water has been added.

6. Concrete can be made on a building site, or it may be used as the materials for making prefabricated units in a plant.

7. To get the best of concrete the following considerations should be kept in mind (помнить).

8. When the concrete hardens and sets, the resulting material gains great strength.

9. The reinforcing of concrete was first introduced in France in 1861 by Joseph Monier, who constructed flower pots, tubs and tanks

10. Since 1896 the development of reinforced concrete work has made great progress.

11. Steel does not undergo shrinkage or drying.

12. Steel constructions with reinforced concrete have become the most important building materials that were invented in centuries.

13. By giving concrete a big squeeze after it has hardened, builders can increase its elasticity ten times so that it will bend under a heavy load without breaking.

14. This is important in building bridges, viaducts, and floors of large buildings.

15. The simplest way to pre-stress concrete is to put steel wires or roads in the concrete when it is poured.

16. Until recently, the aim of engineers was to make concrete with as few bubbles as possible.

17. This concrete is made by adding an agent, which foams to form the bubbles when the concrete is mixed.

18. Scientists are working on research into the behaviour of cement and concrete under all kinds of conditions.

19. The principle of reinforced earth is analogous to that of reinforced concrete.

20. Buildings of reinforced concrete may be constructed with load-bearing walls

or with a skeleton frame.

21.The principle of reinforced earth is analogous to that of reinforced concrete

22. A built-in wardrobe requires less space than a movable one of similar capacity.