ACI Concrete Strength Testing Technician Practice Test

What factor can adversely affect concrete strength?

1. Excess water in the mix

2. Proper mixing techniques

3. Using high-quality aggregates

4. Controlling the curing temperature

The correct answer is: Excess water in the mix

Excess water in the concrete mix has a direct negative impact on its strength. When too much water is added, it increases the water-to-cement ratio, which can weaken the bonds formed during hydration. Concrete gains its strength as the cement reacts with water, and an excess of water dilutes this reaction, preventing optimal hydration of the cement particles. This results in a lower overall compressive strength of the cured concrete. Moreover, excessive water can lead to other issues, such as increased porosity and decreased durability, making the concrete more susceptible to environmental damage. Maintaining the proper water-to-cement ratio is crucial for achieving the desired strength and performance characteristics of concrete in construction.