Florida DOT Concrete Batchman/Operator Practice Exam

What can result from not adjusting batch water when using admixtures like Calcium Nitrite?

1. Decreased strength of concrete

2. Increased drying time

3. Excessive air pockets

4. Reduced workability

The correct answer is: Decreased strength of concrete

When using admixtures such as Calcium Nitrite, it is essential to adjust the batch water accordingly to maintain the desired performance characteristics of the concrete. Failing to do so can result in decreased strength of the concrete. This diminishment occurs because admixtures can alter the water-cement ratio, which is vital for achieving the intended strength and durability of the concrete mix. If the additional water from the admixture is not compensated for, it can lead to an excess amount of water in the mix, thereby weakening the bond between aggregates and cement, ultimately resulting in lower compressive strength. In the context of the other options, while increased drying time, excessive air pockets, and reduced workability can also be influenced by improper adjustment of batch water and admixtures, the most direct and critical outcome related to not managing the water in this scenario is the decrease in concrete strength. The integrity and load-bearing capacity of concrete are primarily affected by the water-cement content, making strength a fundamental aspect of concrete performance.