Tools, Equipment & Safety Procedures Flashcards

What is the primary advantage of using a magnesium float over a wood float?

Answer: It glides more easily and does not absorb moisture from the concrete

Magnesium floats do not swell or warp from moisture and glide smoothly, making them preferred for initial floating on air-entrained concrete.

During power troweling operations, a worker should maintain a safe distance from the rotating blades by:

Answer: Keeping feet and hands clear of the blade radius at all times

Rotating power trowel blades can cause severe lacerations; all personnel must keep extremities outside the blade sweep zone.

What does the term 'radius of action' mean in reference to an internal concrete vibrator?

Answer: The distance from the vibrator head within which concrete is effectively consolidated

The radius of action is the effective consolidation zone around a vibrator head; insertions must overlap this radius for full coverage.

Why is it important to cure concrete after finishing?

Answer: To maintain moisture so hydration continues and strength develops properly

Curing retains moisture needed for cement hydration, ensuring concrete achieves its design strength and durability.

A come-along (concrete rake) is used to:

Answer: Move and spread fresh concrete before screeding

A come-along is a long-handled rake used to move and roughly spread fresh concrete from the discharge point prior to screeding.

When using a wet-cut concrete saw, what is the primary purpose of the water supply?

Answer: Suppress silica dust and cool the diamond blade

Water flow suppresses respirable silica dust at the source and dissipates heat to extend diamond blade life.

Which condition would require immediately stopping power trowel operations and clearing the area?

Answer: A fuel or oil leak detected on the machine

A fuel or oil leak creates an immediate fire hazard; the machine must be shut down and the area cleared until the leak is repaired.