Florida DOT Concrete Batchman/Operator Practice Exam

Which type of water reducer aims to maintain workability while delaying set time?

1. Type A

2. Type F

3. Type D

4. Type G

The correct answer is: Type D

The type of water reducer designed to maintain workability while delaying the set time is classified as Type D. This type is particularly useful in concrete applications where extended workability is necessary, allowing for easier handling during placement without compromising the strength and durability of the concrete once it cures. Type D water reducers effectively achieve this by incorporating specific chemical components that modify the hydration process, thereby slowing down the setting time. This feature is advantageous in hot weather conditions or when projects require longer finishing times, granting operators the flexibility to work with the mix without it setting too quickly. Other types of water reducers, such as Type A, primarily reduce the water content in the mix without significantly altering the set time. Type F is often used for high-performance concrete, focusing on strength and workability but not specifically on delaying set time. Type G, associated with superplasticizers, enhances fluidity and workability but usually does not elongate setting time to the same extent as Type D does. Thus, Type D stands out for its unique combination of maintaining workability while delaying concrete set time.