Color & Texture Finishing 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 Color & Texture Finishing flashcards as text
When applying a surface retarder to achieve an exposed aggregate finish, how should the retarder be applied?
Answer: Applied evenly to the fresh concrete surface immediately after screeding and floating
Surface retarder is applied evenly to freshly placed concrete to delay set of the surface paste, allowing it to be washed away later to expose aggregate.
A broom finish is specified for an exterior walkway. Which broom orientation produces the most slip resistance?
Answer: Perpendicular to the direction of foot traffic
Brooming perpendicular to the direction of travel creates ridges that interrupt forward motion and provide the greatest slip resistance.
What is the primary difference between an acid stain and a water-based concrete stain?
Answer: Acid stains react chemically with concrete minerals to create color; water-based stains penetrate and deposit pigment
Acid stains react with calcium hydroxide in the concrete to create permanent, variegated color, while water-based stains deposit pigment particles into the surface pores.
When using a stamping tool on colored concrete, the finisher notices the pattern is becoming shallow and indistinct. What is the most likely cause?
Answer: The concrete has become too stiff and the stamping window has passed
If concrete stiffens beyond the optimal stamping consistency, impressions become shallow; finishers must monitor surface stiffness and work efficiently within the stamping window.
Which sealer type provides the highest gloss and most color enhancement for decorative concrete surfaces?
Answer: High-solids polyurethane or epoxy sealer
High-solids polyurethane and epoxy sealers form a thick film that produces the highest gloss finish and significantly enhances color depth in decorative concrete.
A concrete finisher is working on a colored slab in direct sunlight on a hot day. What special concern applies to the stamping operation?
Answer: The concrete will set faster, shortening the stamping window significantly
High temperatures accelerate cement hydration, dramatically shortening the stamping window and requiring faster coordination among crew members.
What is the correct method for neutralizing an acid stain on concrete before sealing?
Answer: Scrub with a baking soda and water solution, then rinse thoroughly with clean water
A baking soda (sodium bicarbonate) and water solution neutralizes residual acid, and thorough rinsing removes all reaction byproducts before sealer application.