Alabama Contractors License Practice Exam

What effect does hot weather have on curing concrete?

1. Speeds up curing

2. Delays curing

3. Has no effect

4. Requires more water

The correct answer is: Delays curing

The assertion that hot weather delays curing is related to the physical and chemical processes involved in concrete hydration. In hot weather, the rate of evaporation of water from the surface of the curing concrete increases significantly. When concrete cures, it relies on water to facilitate the chemical reactions that strengthen the mixture. If there is insufficient water due to rapid evaporation, the hydration process may become incomplete, leading to delays in achieving the desired strength and durability. In addition, higher temperatures can also cause the concrete to set more quickly, which may lead to a phenomenon known as "flash setting." However, this does not necessarily aid in the curing process, as the strength gained may not be optimal if the concrete dries out too rapidly. Also, managing concrete curing in hot weather typically requires additional measures to retain moisture, such as using curing compounds, covering the surface with wet burlap, or employing misting techniques. This highlights the importance of adequate moisture during the curing phase to ensure proper development of concrete strength. Hence, the implications of high temperatures on the curing process substantiate the idea that they can cause complications rather than delays in the hydration process itself.