11. Use of Admixtures in Fresh Concrete

Try these first

1. 1.

   What is an admixture?

   Hint

   Think about what we change in the concrete.

2. 2.

   Name one type of admixture that improves workability.

   Hint

   It has 'plastic' in its name.

3. 3.

   What is the primary purpose of a plasticizer?

   • A. Increase water content
   • B. Improve workability
   • C. Speed up curing

   Hint

   Think of what plasticizers do.

4. 4.

   True or False: Retarders are used to speed up the setting of concrete.

   • True
   • False

   Hint

   Consider if they make setting faster or slower.

5. 5.

   You are advising a contractor on a concrete mix for a large outdoor project in a hot climate. What admixtures would you recommend? Justify your choices.

   Hint

   Consider the impacts of heat on setting and how admixtures can counteract that.

6. 6.

   A construction project is facing delays due to cold weather. What specific admixture could aid in accelerating concrete strength and why is it important?

   Hint

   Think about why quick setting could benefit a construction timeline during winter.