Question

The concrete arrives on a construction project stiffer than needed and the workers add water to the mix. How will this affect the mix?

1) Does not affect the mix
2) Makes the mix weaker
3) Increases the water to cement ratio
4) Both 2 and 3

Answer 1

Adding water to stiffer concrete weakens the mix and increases the water to cement ratio.

Step-by-step explanation:

When water is added to concrete that is stiffer than needed, it affects the mix in two ways:

1. The mix becomes weaker because the added water dilutes the cement paste, which is responsible for holding the aggregates together.
2. The water to cement ratio increases, which can negatively impact the strength and durability of the concrete. A higher water to cement ratio can result in increased porosity, reduced strength, and increased drying shrinkage.

Therefore, option 4) Both 2 and 3 is the correct answer.