Question 4
(a) State two reasons for curing concrete.
(b) State two functional requirements of a roof.
(c)(i) Sketch a pictorial view of a timber profile for setting out a strip foundation.
(ii) State two advantages of using deep strip foundation over the wide strip
foundation.
Observation
Most candidates were able to:
- State two reasons for curing concrete.
- State two functional requirements of a roof.
- Sketch a pictorial view of a timber profile for setting out a strip foundation.
However, many of them failed to state two advantages of using deep strip foundation
over the wide strip foundation.
The expected response to question 4 is as given below:
4 (a) Two reasons for curing concrete:
(i)To achieve maximum strength
(ii)To make it durable)
(iii)To prevent excessive or rapid drying
(iv)To avoid cracks in concrete
(v)To make it resistant to abrasion
(vi)To make it dense.
(vii)To facilitate hydration of cement.
(b) Two functional requirement of roof:
- to keep out weather ( rain, wind etc.)
- should have adequate strength;
- should be stable at all times;
- should provide comfort to the occupants;
- should be able to provide required degree of sound insulation;
- should be durable.
(c) i.
ii. Two advantages of using deep strip foundation over the wide strip foundation;
- It can withstand seasonal changes in clayey soils;
- Width of trench is narrower;
- It provides greater resistance to fracture from equal settlement;
- The trench is filled with concrete making it faster or time saving.