ACI Decorative Concrete & Stamping 3

Question 1

What is the purpose of back-rolling a sealer coat applied to stamped concrete?

Accepted Answer

To remove excess sealer and prevent puddle buildup in low areas

Answer

Back-rolling after spraying or rolling distributes sealer evenly and prevents it from pooling in the stamped texture depressions, which can cause whitening or peeling.

Question 2

Acid staining relies on which chemical reaction to produce color in concrete?

Accepted Answer

Reaction between acid and free lime (calcium hydroxide) in hardened concrete

Answer

Acid stains react with calcium hydroxide in cured concrete to form colored metallic salts that permanently bond with the concrete surface.

Question 3

Which of the following best describes 'integral color' in decorative concrete?

Accepted Answer

Color mixed throughout the entire concrete batch before placement

Answer

Integral color is a pigment added to the concrete mix so that color is uniform throughout the full depth of the slab, not just on the surface.

Question 4

What is the function of a texture mat (skin) in decorative stamping?

Accepted Answer

To impart a surface texture without creating a repeating joint pattern

Answer

Seamless texture skins or mats apply realistic surface texture — such as stone or slate grain — without the visible repeat lines that ridged stamp tools produce.

Question 5

Why is it important to keep stamp tool patterns aligned during a decorative pour?

Accepted Answer

Misalignment creates visible breaks in the pattern that look unnatural

Answer

Misaligned stamp tools disrupt the repeating decorative pattern, making joints and grout lines appear crooked or inconsistent, which compromises the appearance.

(ACI) American Concrete Institute Concrete Finisher Practice Test

(ACI) American Concrete Institute Concrete Finisher Practice Test

ACI Decorative Concrete & Stamping 3