20 Express your opinion on the magnitude of the Roman Coliseum and discuss it with your partner using the expressions from Appendix 1.

21 Topics for projects and presentations:

1. Constructivism.

2. Residential buildings.

3. Public buildings.

4. Renovation and restoration.

5. Architecture and ecology.

PART II. BUILDING MATERIALS

“We move through negative spaces and dwell in positive spaces.”

Matthew Frederick (architect)

Unit 3

	Exterior detail	Interior detail

Figure 3.1 Evry Cathedral, Essonne, France

1 a) Explain how the following words are connected with “bricks”:

ceramic, clay, lime, heat and cooling, firing temperature, kiln, iron content.

b) Read the information below and compare your answers:

A “brick” is a block of ceramic material used in masonry construction, usually laid using various kinds of mortar. It has been regarded as one of the longest lasting and strongest building materials used throughout history.

"Bricks" for building may be made from clay, shale, soft slate, calcium silicate, concrete, or shaped from quarried stone. However, true bricks are ceramic, and therefore created by the action of heat and cooling.

Clay is the most common material, with modern clay bricks formed in one of three processes - soft mud, dry press, or extruded.

Normally, brick contains the following ingredients:

• Silica (sand) - 50% to 60% by weight;

• Alumina (clay) - 20% to 30% by weight;

• Lime - 2 to 5% by weight;

• Iron oxide - 5 to 6% (not greater than 7%) by weight;

• Magnesia - less than 1% by weight

The fired colour of clay bricks is influenced by the chemical and mineral content of raw materials, the firing temperature and the atmosphere in the kiln. For example, pink coloured bricks are the result of a high iron content, white or yellow bricks have a higher lime content. Most bricks burn to various red hues, if the temperature is increased the colour moves through dark red, purple and then to brown or grey at around 1,300 °C. Calcium silicate bricks have a wider range of shades and colours, depending on the colourants used.

2 Find information about history, methods of manufacture, and characteristics of bricks and make a report.

3 Discuss the following:

• Write a paraphrase of each proverb. • Say whether you agree or not, and why.

4 A) In what context do you think the following words and phrases will appear in the text?

•hand-moulded •moist clay •firing •manufacturing process •quarry •extraction •cement mortar •surmounted by a corbelled structure

2. Read the text quickly and check your answers:

Originally, bricks were hand-moulded from moist sun clay and then sun-baked, as is still the practice in certain arid climates. The firing of clay bricks dates back well over 5000 years, and is now a sophisticated and highly controlled manufacturing process; yet the principle of burning clay, to convert it from its natural plastic state into a dimensionally stable, durable, low-maintenance ceramic material, remains unchanged. The quarrying of clay and brick manufacture are high-energy processes, which involve the emission of considerable quantities of carbon dioxide and other pollutants including sulphur dioxide. The extraction of clay also has long-term environmental effects, although in some areas former clay pits have now been converted to bird sanctuaries or put to recreational use. However, well-constructed brickwork has a long life with low maintenance, and although the use of Portland cement mortar prevents the recycling of individual bricks, the crushed material is frequently recycled as aggregate in further construction.

The elegant cathedral at Evry near Paris (Fig. 6.1), designed by Mario Botta, illustrates the modern use of brickwork. The cathedral of Saint Corbinian, built with 670,000 bricks, was dedicated in 1997. The building exhibits fine detailing both internally and externally. Externally the cylindrical form rises to a circle of trees. Internally the altar is surmounted by a corbelled structure leading one’s view upwards to the central rooflight. Three-dimensional internal brickwork is finely detailed to generate the desired acoustic response.