What characteristic of concrete is most affected by the water-cement ratio?

The strength of concrete is significantly influenced by the water-cement ratio. This ratio is critical because it determines the amount of water available for the hydration process of the cement. A lower water-cement ratio usually results in higher strength, as there is less water to create voids within the concrete, making it denser and more durable. Conversely, an excessive amount of water can weaken the concrete, producing a mix that is more susceptible to cracking and failure under load.

This relationship between the water-cement ratio and concrete strength is foundational in concrete technology. Engineers and technicians carefully calculate the ideal ratio to achieve the desired strength characteristics for specific applications. Therefore, the correct answer highlights the importance of managing the water-cement ratio to ensure that the concrete meets its structural performance requirements.