3. Aggregates for Concrete

Try these first

1. 1.

   What is the classification of aggregates based on size?

   Hint

   Think about the sieve sizes.

2. 2.

   Name one property of aggregates.

   Hint

   It's a measurement related to density.

3. 3.

   What type of aggregates are smaller than 4.75 mm?

   • Fine Aggregates
   • Coarse Aggregates
   • All-in Aggregates

   Hint

   Think about the sieve classification.

4. 4.

   True or False: Coarse aggregates provide compressive strength to concrete.

   • True
   • False

   Hint

   Consider the size and role of these aggregates.

5. 5.

   Calculate the Fineness Modulus of a sample of sand if 25% is retained on a 4.75 mm sieve, 15% on a 2.36 mm sieve, 20% on a 1.18 mm sieve, 30% on a 600 μm sieve, and 10% on a 300 μm sieve.

   Hint

   Sum the percentages for all relevant sieves.

6. 6.

   Discuss how the shape of aggregates can impact the strength and workability of concrete mixtures. Provide examples.

   Hint

   Consider what happens when you stack different shaped items together.