Why is it important to control the water-cement ratio in concrete?

Controlling the water-cement ratio in concrete is crucial for balancing workability and strength. The water-cement ratio determines the concrete's final strength and durability. A lower ratio typically results in stronger concrete, as there is less water present, leading to a denser final product. However, if the ratio is too low, the mix may become too dry and difficult to work with, reducing workability.

On the other hand, a higher water-cement ratio improves workability but can significantly weaken the concrete's compressive strength once it cures. Achieving the right balance is essential for ensuring that the concrete can be adequately placed and finished while also achieving the desired mechanical properties once hardened.

Other options, such as lowering project costs or improving concrete color, do not directly relate to the fundamental properties that the water-cement ratio influences. Additionally, while drying time may be affected by the water-cement ratio, it is not the primary reason for controlling it. The primary focus should be on how the ratio affects the interaction between workability and strength, which is pivotal in structural applications.