Red Seal Concrete Finisher Practice Exam

What is a common cause of concrete surface discoloration?

1. Excessive water in the mix

2. Inconsistent curing and drying conditions

3. The type of trowel used

4. Temperature fluctuations

The correct answer is: Inconsistent curing and drying conditions

Discoloration of concrete surfaces is often a result of inconsistent curing and drying conditions. Curing is crucial for achieving uniform hydration throughout the concrete, which affects not only its strength but also its color. When certain areas of the concrete dry faster or are cured differently from others, it can lead to variations in color due to uneven moisture retention and evaporation. For example, if one part of the slab is kept moist while another part is exposed to sunlight and dries out quickly, the differences in moisture levels can result in uneven curing. This inconsistency jeopardizes the color integrity of the surface as some sections may appear darker or lighter than others, showcasing the importance of maintaining uniform curing practices to ensure an even appearance across the entire surface.