Decorative Concrete & Stamping 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 Decorative Concrete & Stamping flashcards as text
What does 'stamping window' refer to in decorative concrete work?
Answer: The period of time during which concrete is plastic enough to accept stamp impressions
The stamping window is the limited timeframe after placement and color hardener application when the concrete is firm enough to hold a pattern but still plastic enough to accept a deep stamp impression.
Which of the following best describes the 'two-color' technique in stamped concrete?
Answer: Using a base integral color combined with a contrasting powdered release agent for a highlighted, antiqued effect
The two-color technique layers a base integral or hardener color with a contrasting release agent color that remains in the recesses after washing, creating a natural stone-like variation.
When applying a second coat of sealer to stamped concrete, what is the recommended minimum wait time after the first coat?
Answer: 30 minutes to 1 hour, or until the first coat is tack-free
The first sealer coat should be tack-free — typically 30 minutes to 1 hour depending on temperature and humidity — before a second coat is applied to prevent solvent entrapment and bubbling.
Which substrate condition will cause a concrete overlay or micro-topping to delaminate prematurely?
Answer: An existing surface contaminated with curing compound, oil, or sealer residue
Curing compounds, sealers, oils, and other contaminants block the chemical bond between the overlay and the existing concrete, leading to delamination.
Why should stamped concrete in freeze-thaw climates be sealed with a breathable or lower-solids sealer rather than a thick film-forming sealer?
Answer: Thick non-breathable sealers can trap moisture, leading to spalling and delamination from freeze-thaw pressure
In freeze-thaw environments, moisture trapped beneath a thick impermeable sealer can freeze, expand, and cause surface spalling or sealer delamination.
What is the correct procedure for removing powdered release agent residue after stamping is complete and before sealing?
Answer: Allow the slab to cure, then rinse thoroughly with water and light scrubbing
After adequate curing, the slab is rinsed and lightly scrubbed with water to remove loose release agent powder before sealing, ensuring proper sealer adhesion.
Which ACI document provides guidelines for specifications and testing of concrete used in decorative and architectural applications?
Answer: ACI 303R — Guide to Cast-in-Place Architectural Concrete Practice
ACI 303R is the primary ACI guide addressing cast-in-place architectural and decorative concrete practice, including surface finishes, forming, and quality expectations.