Unit 1 modern construction

LEAD-IN

1. Divide the words from the box into two groups.

Timber, steel, mortar, cement, concrete, glass, sand, rock, clay, brick, gravel, wood, concrete slab

Natural materials	Man-made materials

2. What materials are used for the construction of the buildings presented in the pictures?

3. What modern construction techniques do you know?

4. What construction materials are used in them?

5. What modern construction technologies are widely used in our city?

Text 1 modern construction materials

C onstruction material is any material which is used for a construction purpose. Many naturally occurring substances, such as clay, sand , wood  and rocks, even twigs and leaves have been used to construct buildings. Apart from naturally occurring materials, many man-made products are in use, some more and some less synthetic. The manufacture of building materials is an established industry in many countries.

One of the most wide spread construction material in the modern world is cement. Nearly six billion tonnes of this very important commodity is produced every year. Cement is the main ingredient used in the production of blocks for construction works. It is combined with aggregates (sand, gravel and stones) to make concrete and used as slurry for filling cracks in all kinds of structures. It is also used for masonry work, plastering and pointing. This versatile capability allows cement to be used in all kinds of structures including buildings, bridges. dams, docks, harbours and roads.

Manufacturing cement requires a very heavy capital investment in quarries, labour, plant and equipment. As a result, only national governments and businessmen with deep pockets are able to set up cement manufacturing plants. However, small scale businesses and entrepreneurs can get involved in the cement business by joining the distribution chain. They can be dealers who buy directly from the cement manufacturers or major importers. Or they can be retailers who sells the product directly to home builders and contractors.

  Aggregates are raw earth materials which have been used since prehistoric times in building and construction. Aggregates fall into two broad categories - coarse aggregates (such as crushed stones, gravel, pebbles, and granite) and fine aggregates (usually sand and clay). In modern construction work, aggregates are combined with cement to produce concrete and mortar. Using aggregates gives volume, stability, resistance to wear or erosion, and other desired physical properties to all kinds of structures – buildings, bridges, roads etc.

Wood is one of the oldest and most commonly used construction materials in the world. Despite the growing threat of deforestation, wood has remained in high demand as a building material because of its reasonable cost, availability, attractive appearance and long life (if protected from insects and moisture).

 Wood used in construction work is commonly referred to as timber (or ‘lumber’ in the US and Canada). Timber is sawn into planks or poles and used as supporting materials (beams and pillars), in roof and ceiling construction, door and window frames. Timber is also commonly used in flooring, panelling and general finishing.

S teel is valued in modern construction for many reasons. Steel is cheap. A strong material other than iron or concrete could now be used to build upwards and outwards while maintaining structural integrity. Steel only needs a very small diameter to hold a large amount of weight, and when surrounded in a concrete form, it becomes very strong indeed. Steel is flexible, it’s a favourite of designers who like sweeping curves but need to maintain strength.

Steel is much better for the environment than other metals; its manufacturing is cleaner and it can be recycled easily. Steel is used in trusses, columns, beams, frames, arches and etc.

TASKS