Construction Tools, Equipment and Machinery
This domain asks which tool or machine suits a described operation, what its correct use is, and how output or capacity is estimated. Expect matching items on hand tools and small calculations on machine productivity.
Hand tools and their work
- Trowel for laying and spreading mortar; float for finishing plaster; plumb bob and spirit level for verticality and level; mason's line and pins for alignment; bolster and chisel for cutting masonry; sieve for screening sand; wheelbarrow for short-haul carriage.
- Tools must be matched to material: a steel float is not used to finish a costly plaster where a wooden float is specified, and a heavy bolster is not used to cut glazed tiles.
Machines and correct use
- Concrete mixer, batching plant, needle vibrator, hoist, tower crane, excavator or backhoe, roller, paver and total station.
- Batching by weight is more accurate than by volume; the water-cement ratio, not the mixer size, controls strength.
- Needle vibrator: insert vertically, spacing about 0.5–0.75 m, withdraw slowly, stop when the surface glistens; never use it to push or spread concrete.
Worked example
An excavator has a 0.9 m³ bucket and a 30-second cycle. Theoretical cycles per hour = 3600 ÷ 30 = 120, so theoretical output = 120 × 0.9 = 108 m³/h. Applying 80% efficiency gives 108 × 0.8 = 86.4 m³/h, and a 7-hour working day yields about 605 m³.
Traps that cost marks
Using the vibrator as a spreader, which segregates the mix; over-vibration causing bleeding; confusing struck capacity with heaped bucket capacity; treating mixer drum volume as concrete output per batch; ignoring efficiency factors in output calculations.