Construction
Scope
Construction tests building materials, structural systems, surveying, construction management, drawings, and site safety. Questions often require reading a dimension, calculating material quantity, or selecting a safe construction sequence.
Core rules
- Structural loads include dead load, live load, wind, and seismic load; members must be sized for the governing combination.
- Concrete volume = length x width x thickness, with all dimensions in the same unit.
- Construction drawings use scales; a scale of 1:100 means 1 drawing unit represents 100 real units.
- Formwork shapes fresh concrete and is removed after sufficient strength gain; it is not permanent reinforcement.
- Site safety requires fall protection, excavation support, and control of hazardous energy.
Worked example
A slab is 5 m long, 4 m wide, and 0.15 m thick. Concrete volume = 5 x 4 x 0.15 = 3 m3. With 5% waste allowance, order 3 x 1.05 = 3.15 m3. If cement content is 300 kg/m3, cement required = 3.15 x 300 = 945 kg. Reasoning: calculate net volume, add waste, then apply the mix quantity.
Traps
Mixing centimetres and metres causes large quantity errors. Confusing formwork with reinforcement misunderstands structural function. Ignoring waste underestimates orders. Reading a scaled drawing without converting scale gives wrong dimensions.