These six original questions get harder as you go. Write each answer on paper before opening its explanation.
This set is part of SPM subjects and learning resources. The structured answer self-review tool helps you check your working afterwards.
Questions
Question 1: A concrete beam is 2.5 m long, 200 mm wide and 300 mm deep. Find its volume in m³ (2 marks).
Answer
Convert first: 200 mm = 0.2 m and 300 mm = 0.3 m.
Volume = 2.5 × 0.2 × 0.3 = 0.15 m³.
Question 2: Concrete has a density of 2 400 kg/m³. Find the mass of the beam in Question 1 (2 marks).
Answer
Mass = density × volume = 2 400 × 0.15 = 360 kg.
Check: 0.15 m³ is a little more than a tenth of a cubic metre, so a mass of 360 kg is sensible.
Question 3: Explain why newly poured concrete is cured (3 marks).
Answer
Concrete gains strength as cement reacts with water, and this reaction needs moisture. Keeping the surface damp stops water from evaporating too fast. So the concrete gains strength steadily and is less likely to crack from shrinkage.
Question 4: A diagram shows a retaining wall with weep holes near the base. State the function of the weep holes (2 marks).
Answer
The weep holes let water collected behind the wall drain out through it. This stops water pressure building up against the wall, so the wall only has to resist the soil.
Question 5: A column load of 90 kN acts on a footing of area 1.5 m². Soil capacity is 50 kN/m². Is the footing adequate? (3 marks)
Answer
Pressure = 90 ÷ 1.5 = 60 kN/m².
This is above the capacity of 50 kN/m², so the footing is not adequate.
The minimum area is 90 ÷ 50 = 1.8 m², so the area must increase by at least 0.3 m².
Question 6: Explain, using sequence and reasons, why reinforcement is fixed before concrete is poured into formwork (3 marks).
Answer
Steel bars must sit at exact positions inside the member, and this is only possible while the formwork is empty. The concrete is then poured around them so the bars are fully surrounded. If concrete were poured first, the bars could not be placed, and the member would lack the tensile strength the steel gives it.
If you got these wrong
- Questions 1, 2 and 5: review checking units in a classroom calculation and supporting a design choice with evidence.
- Questions 3 and 6: review explaining a process in a clear sequence.
- Question 4: review reading a technical diagram.
For a teacher to go through your attempts, see online one-to-one Civil Engineering Studies tuition.