ACI Adhesive Anchor Installer Certification Practice Exam

How does temperature affect gel time of adhesives?

1. Colder temperatures increase gel time

2. Colder temperatures decrease gel time

3. Temperature does not affect gel time

4. Warmer temperatures increase gel time

The correct answer is: Colder temperatures increase gel time

Temperature significantly influences the gel time of adhesives. In colder temperatures, the curing process of adhesives slows down because chemical reactions that lead to curing and gel formation are temperature dependent. Lower temperatures typically lead to a decrease in the energy available for these reactions, thereby extending the time it takes for the adhesive to reach a gel state. This means that as the temperature drops, the gel time increases, which can impact the overall performance and installation timing of adhesive anchors. In contrast, at warmer temperatures, the reaction rate generally increases, resulting in a shorter gel time. Therefore, it's accurate to affirm that colder temperatures increase gel time, as they delay the setting process of the adhesive due to reduced molecular activity. Understanding this relationship is crucial for proper installation practices in varying environmental conditions.