7.6.1. Chemical Admixtures

Try these first

1. 1.

   What is the role of plasticizers in concrete?

   Hint

   Think about how they help in mixing.

2. 2.

   Name one condition where a retarder would be necessary.

   Hint

   Consider the weather impacts on concrete.

3. 3.

   What type of admixture is used to increase flowability?

   • Plasticizer
   • Superplasticizer
   • Retarder

   Hint

   Think of terms related to 'extra fluid' in concrete.

4. 4.

   True or False: Retarders speed up the setting time of concrete.

   • True
   • False

   Hint

   Consider the purpose of retarders in hot weather.

5. 5.

   Given a project scenario where the concrete needs to set quickly due to cold temperatures, which admixture would be advisable? Justify your choice based on how it affects the setting time.

   Hint

   Think about how temperature affects curing times.

6. 6.

   In a hot weather project, the concrete is setting too quickly, leading to quality issues. Describe how using a retarder could resolve this issue.

   Hint

   Consider why you would want more time when working in heat.