Coastal and Floodplain Construction Inspector's Practice Exam

Concrete exposed to which of the following conditions is assigned an exposure class under ACI 318?

1. Exposure to PVC chemicals

2. Exposure to chlorides from deicing chemicals

3. Exposure to humidity above 90%

4. Exposure to high levels of UV radiation

The correct answer is: Exposure to chlorides from deicing chemicals

Exposure to chlorides from deicing chemicals warrants the assignment of an exposure class under ACI 318 due to the detrimental effects that chlorides can have on concrete. Specifically, chlorides can lead to corrosion of embedded reinforcing steel, which can compromise the structural integrity of concrete structures over time. ACI 318 provides guidelines for evaluating and mitigating risks associated with various environmental conditions, and exposure to chlorides is one of the conditions that necessitates a specific exposure classification to ensure the durability and longevity of concrete in affected environments. In contrast, exposure to PVC chemicals, high humidity, or high levels of UV radiation does not traditionally trigger the same level of attention under ACI 318's framework for exposure classification. While these conditions can affect concrete to varying degrees, they do not present the same immediate and corrosive risks that chlorides from deicing chemicals do, which are specifically recognized and classified in relation to concrete construction standards.