2.4. Measurement of Shrinkage

Try these first

1. 1.

   What is shrinkage in concrete?

   Hint

   Think about moisture and its effects.

2. 2.

   What size are standard test specimens for measuring shrinkage?

   Hint

   Remember the dimensions discussed.

3. 3.

   What is the standard size of a test specimen for measuring shrinkage?

   • 50mm × 50mm × 150mm
   • 75mm × 75mm × 285mm
   • 100mm × 100mm × 300mm

   Hint

   Recall the dimensions mentioned earlier.

4. 4.

   True or False: Shrinkage occurs only when concrete is subjected to an external load.

   • True
   • False

   Hint

   Consider the definition of shrinkage.

5. 5.

   A concrete prism was subjected to a drying environment and its length decreased from 285mm to 284.5mm after one year. Calculate the shrinkage strain.

   Hint

   Use the shrinkage strain formula.

6. 6.

   Discuss the implications of not measuring shrinkage accurately in a large building project. Give at least three potential consequences.

   Hint

   Think about how misjudged materials lead to bigger issues.