3.5.7. Alkali-Aggregate Reactivity (AAR)

Try these first

1. 1.

   What does AAR stand for?

   Hint

   It involves a reaction between alkali and aggregates.

2. 2.

   Can all aggregates react with alkalis?

   Hint

   Think about the types of silica.

3. 3.

   What does AAR refer to?

   • Alkali-Aggravated Reactivity
   • Alkali-Aggregate Reactivity
   • Alkaline Aggregate Reaction

   Hint

   Focus on the terms related to alkalis and aggregates.

4. 4.

   True or False: All aggregates react with alkalis in concrete.

   • True
   • False

   Hint

   Consider which minerals are likely to react.

5. 5.

   Consider a concrete structure built using reactive aggregates and ordinary cement. Describe the timeline of events that might occur due to AAR. Include potential failure modes and how you would prevent them.

   Hint

   Think about the factors of time, moisture, and chemical reactivity.

6. 6.

   Analyze the long-term effects of not controlling moisture in a concrete structure built with reactive aggregates. What engineering solutions could reverse damage once cracks form?

   Hint

   Consider both short-term and long-term implications of moisture not being managed.