What is the significance of measuring the absorption of coarse aggregate?

• A. To determine its color stability
• B. To evaluate freeze-thaw resistance
• C. To assess bond strength with cement
• D. To calculate water-cement ratio

Answer: (D)

Measuring the absorption of coarse aggregate is significant primarily because it helps in calculating the water-cement ratio, which is a critical factor in concrete mix design. The absorption rate indicates how much water the aggregate can hold, which directly affects the amount of water that needs to be added to achieve the desired consistency and strength of the concrete mix. If the aggregate absorbs a significant amount of water, it will reduce the amount of water required in the mix, which influences the final properties of the concrete, including workability, durability, and compressive strength.

Understanding the absorption of coarse aggregate can help ensure that the concrete can be mixed properly to achieve the specified performance criteria. This is crucial for the overall quality and longevity of concrete structures. Therefore, knowing the absorption capacity aids in accurate mix design, ultimately leading to improved concrete performance.