North Carolina General Contractors Practice Exam

In what scenario would you most likely use an accelerator in concrete mixing?

1. During warm weather

2. During rainy conditions

3. During cold weather

4. During dry weather

The correct answer is: During cold weather

Using an accelerator in concrete mixing is particularly beneficial during cold weather. In colder temperatures, the setting and curing process of concrete is significantly slowed down due to the lower ambient temperatures. This delay can lead to difficulties in achieving the desired strength and durability of the concrete, which is critical for construction projects. An accelerator works by promoting faster hydration of the cement in the concrete mix, allowing the concrete to set and gain strength more quickly, despite the chill. This can be especially important in ensuring that concrete achieves its necessary properties before exposure to potentially damaging cold conditions, such as freezing temperatures. In contrast, while other weather conditions like warm, rainy, or dry might influence the concrete mixing process, they typically do not necessitate the urgent need for accelerators like cold weather does. For instance, in warm weather, setting times could occur too quickly due to heat, while rain may require other considerations such as water retention and workability adjustments rather than an accelerator.