Question 5
(a) State three factors to be considered before excavating a foundation trench.
(b) Explain each of the following activities in relation to site operation:
(a) site clearing;
(b) site leveling.
(c) State two construction requirements of a steel reinforcing bar placed in a wide-strip foundation.
Observation
Most candidates were able to:
Explain each of the following activities in relation to site operation:
(a) site clearing;
(b) site leveling.
- List threematerials used for pavement construction.
However, some of the candidates were not able to:
- state two reasons for the construction of kerbs on access roads.
- state two reasons for using a metal fencewall gate instead of a wooden gate.
The expected response to question 5 (a) and (c) is as given below:
Factors to be considered before excavating a foundation trench:
- method of ensuring safety when working in the trench;
- type(s) of excavation machinery/tools to use;
- method of keeping excavation free from ground water;
- length of time excavation will be left open;
- method of preventing trench sides from caving in.
(c)Constructional requirements of a steel reinforcing bar placed in a wide-strip foundation:
to resist tensile stresses;
- to strengthen the concrete foundation;
- to prevent fracture to foundation concrete;
- must have adequate cover.