12.1. Tests to Perform

Try these first

1. 1.

   What does a slump test measure?

   Hint

   Think about the ease of placement.

2. 2.

   Why is compressive strength tested at 7 and 28 days?

   Hint

   Consider the curing process of concrete.

3. 3.

   What is the primary purpose of the slump test?

   • To measure density
   • To evaluate workability
   • To determine strength

   Hint

   Consider what ease of placement means.

4. 4.

   True or False: Compressive strength tests should only be performed at 28 days.

   • True
   • False

   Hint

   Think about early strength development.

5. 5.

   You are tasked with designing a concrete mix for a project but your initial test shows a slump of only 25mm when 100mm is ideal. Discuss possible adjustments and their implications.

   Hint

   Be mindful of the water-cement ratio in your adjustments.

6. 6.

   During compressive strength testing, if you unexpectedly find a cube failing at 20 MPa while the target is 30 MPa, what might be the causes, and how would you address them?

   Hint

   Think about common issues in material selection or mixing.