What does the term SSD stand for in concrete terminology?

In concrete terminology, SSD stands for "Saturated Surface-Dry." This term is crucial in concrete technology because it describes a specific condition of aggregate material. When aggregates are in the saturated surface-dry state, they contain water in the pores but have no free water on their surfaces. This condition is important for achieving accurate measurements when mixing concrete, as the water content in the aggregates can significantly affect the water-to-cement ratio, which in turn influences the strength and durability of the concrete.

Understanding the SSD state helps ensure that the correct amount of water is added to the mix, thereby optimizing the hydration process and ensuring the desired performance characteristics of the cured concrete. This terminology is widely used among professionals in the field to ensure consistency and quality in concrete production and execution.