Effect of Aggregate on Workability of Concrete
Objective: The purpose of this demonstration is to determine the effect of different aggregates on the workability of the resulting concrete.
Materials and Supplies:
- two containers labeled:
- "limestone chip aggregate"
- "sand aggregate"
- small limestone chips(pea gravel)
- Add 1 part of cement and 1/2 part water to each container. Suggested amounts include 50 grams of concrete and 25 ml of water.
- Mix to make the cement paste.
- To the appropriate container, add 3 parts (150g) of limestone chips and mix.
- To the second container, add 3 parts (150 g) of sand and mix.
- Using gloved hands, knead the concrete to determine its workability.
- Which concrete mixture is more workable? Why?
The sand aggregate is more workable, because the smaller particles facilitate flow. The larger particles of the gravel hinder it.