MATERIALS

Question 1

Explain how prestressed concrete has better performance than standard concrete

Answer 1

Prestressed concrete: concrete is placed in compression prior to placement, as concrete performs poorly in tension. The compressive forces induced, help neutralise the tensile forces to allow greater strength and support greater loads

Question 2

Outline what are geotextiles

Answer 2

Geotextiles are permeable fabrics which, when used in association with soil, have the ability to separate, filter, reinforce, protect, or drain

Question 3

Describe and outline the manufacture process of bricks

Answer 3

Bricks are ceramics made from clay mixed with water, the mixture is semi-dry and allowed to fall into a steel mould or die block in which it is compressed into a brick shape. This is then placed into a kiln and allowed to dry by heating with fire or exhaust gases. The dry brick is then fired or baked in a furnace at about 1000 to 1200 celsius to full strength.

Question 4

Explain why steel is suitable for reinforcing concrete

Answer 4

Concrete is relatively high in compressional strength but is lacking in tensile strength, comparatively steel is high in tensile strength enhancing the properties of both materials. Steel also has a similar coefficient of thermal expansion to concrete.