Practice Test Geeks(ACI) American Concrete Institute Concrete Finisher Practice Test
← All ACI Flashcard Decks

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

  1. When using dry-shake color hardener on a concrete slab, at what stage should the first application be made?

    Answer: After bleed water has evaporated and the surface can support foot traffic

    Dry-shake hardener is applied after bleed water evaporates and the surface can just support a worker's weight without sinking more than about 1/4 inch.

  2. Which chemical compound is primarily responsible for the color produced by integral iron oxide pigments in concrete?

    Answer: Iron oxide (Fe2O3 or Fe3O4)

    Iron oxide pigments in red, yellow, brown, and black shades are the most common and stable colorants used in integrally colored concrete.

  3. A contractor notices that a stamped concrete patio has 'ghosting' — faint impressions from the stamp that appear lighter than the surrounding surface. What is the most likely cause?

    Answer: Stamping performed too early while bleed water was present

    Stamping while bleed water is still present traps water under the stamp, creating lighter, weaker areas called ghosting.

  4. What is the purpose of a 'release agent' when stamping concrete?

    Answer: To prevent the stamp from bonding to the concrete and add a secondary color accent

    Release agents serve a dual purpose: they prevent stamps from sticking to the surface and add a contrasting antiquing color that highlights pattern details.

  5. A concrete finisher is applying an acid stain to a cured slab. Which safety precaution is MOST critical?

    Answer: Using respiratory protection and chemical-resistant gloves and eye protection

    Acid stains contain hydrochloric acid and metallic salts that can cause severe burns to skin and eyes and emit harmful fumes requiring respiratory protection.

  6. In exposed aggregate finishing, what determines the size and appearance of the aggregate that is revealed?

    Answer: The type of aggregate specified and how deeply the surface mortar is removed

    Both the aggregate gradation specified in the mix design and the depth of surface retardation or washing control the final exposed aggregate appearance.

  7. What happens to the color intensity of integrally colored concrete if excess water is added to the mix on the job site?

    Answer: Color intensity decreases and becomes uneven or washed out

    Adding water increases the water-cement ratio, diluting the pigment concentration and producing lighter, less uniform color with reduced durability.