Red Seal Concrete Finisher Practice Exam

How might high temperatures impact concrete curing?

1. They speed up the curing process

2. They can lead to cracking and surface scaling

3. They have no effect on curing

4. They improve the strength of the concrete

The correct answer is: They can lead to cracking and surface scaling

High temperatures can significantly impact the curing process of concrete, primarily by leading to cracking and surface scaling. When concrete is exposed to elevated temperatures, the rate of evaporation of water from the surface increases. This rapid evaporation can result in inadequate moisture retention within the concrete mix, which is crucial during the curing period for proper hydration of the cement particles. As the water evaporates too quickly, it can create a condition where the surface hardens prematurely while the interior remains soft. This discrepancy can induce stress within the concrete, which may lead to surface cracking. In cases where the concrete is not adequately cured, scaling may also occur, leading to a deterioration of the surface layer over time. Thus, understanding the impacts of temperature on curing is vital for ensuring the durability and longevity of concrete structures. This knowledge helps in implementing proper curing techniques, such as misting or covering, to mitigate these adverse effects during high-temperature conditions.