Question 3
(a) State three desirable properties of hardened concrete.
(b) State three functions of an internal wall.
(i)Explain the reason for providing a landing in stair construction.
Observation
Majority of the candidates were able to:
- state three desirable properties of hardened concrete.
- state three functions of an internal wall.
However, majority of them failed to explain the reasons for providing a landing in a stair construction.
The expected response to question 3 is as given below:
(a) Desirable properties of hardened concrete:
- should be durable;
- should be of the required strength;
- should be of the correct density;
- should be impermeable to water;
- should be resistant to friction;
- should be free from shrinkage cracks;
- should be able to withstand fire;
- should resist indentation.
(b) Functions of an internal wall:
- to assist in carrying the loads imposed on the structure;
- to divide space;
- to provide sound insulation;
- to resist the spread of fire;
- to provide security;
- to support fixtures, fittings and decorations;
- to accommodate services.
(c) Reason for providing landing in a stair construction:
- to allow for change of direction;
- to provide an access for rest.
- to limit the distance someone is likely to fall.
- to break up the span.
- to permit safe passage on the flight of stairs.