Surface Preparation & Finishing Techniques Flashcards
7 cards from real ACI practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Surface Preparation & Finishing Techniques flashcards as text
What is the correct order of finishing operations for a standard exterior broom-finished concrete slab?
Answer: Place → screed → bull float → edge/joint → float → broom → cure
The correct sequence is placement, screeding, bull floating, edging/jointing, hand floating, then brooming, followed by curing.
Which tool is used to create a smooth, flat surface on concrete that is out of reach of a finisher standing at the slab edge?
Answer: Fresno trowel
A Fresno trowel has a long handle allowing a finisher to trowel areas of the slab that cannot be reached by hand.
When finishing concrete near a drain or low point, how should the finisher direct the float or trowel strokes?
Answer: Toward the drain to ensure proper slope and drainage
Finishing strokes should follow the intended slope toward the drain to maintain proper pitch and avoid creating birdbaths (ponding areas).
What condition indicates that concrete is too stiff to finish properly?
Answer: Trowel pressure does not embed the blade and the surface tears or shows drag marks
When the concrete is too stiff, trowel blades skip or tear the surface rather than smoothing it, indicating the finishing window has closed.
Which curing method is most effective immediately after brooming exterior flatwork?
Answer: Applying a liquid membrane-forming curing compound
A liquid curing compound forms a film that retains moisture for hydration, and is practical for exterior flatwork right after brooming.
What is the primary cause of scaling on a concrete surface after the first winter?
Answer: Finishing or applying curing compounds while bleed water is still present, combined with freeze-thaw cycles
Scaling results from a weakened surface layer caused by premature finishing over bleed water or early curing compound application, which is then damaged by freeze-thaw action.
When applying a release agent before stamping decorative concrete, the release agent is used to:
Answer: Prevent the stamps from sticking to the surface and add secondary color variation
Release agents (powder or liquid) prevent stamps from adhering to the fresh concrete and typically add a contrasting antique color effect.