Sandkörnung

Sandkörnung refers to the grain size of sand, which is a measure of the particle diameter within a specific range. It is a key parameter in sedimentology, geotechnical engineering, and construction, influencing the properties of sandy materials such as permeability, compaction, and stability. The term originates from German, where "Sand" means sand and "Körnung" refers to grain size or granularity.

Sandkörnung is typically categorized using standard classification systems like the Wentworth scale, which subdivides particles into various size classes ranging from very fine to coarse. For example, fine sand has particles between 0.125 and 0.25 millimeters, while coarse sand ranges from 0.5 to 2 millimeters. The distribution of grain sizes within a sediment is described by grain size distribution curves, which are critical for understanding the sediment’s behavior and suitability for different applications.

Determining sandkörnung involves sieving or laser diffraction methods, which analyze the particle size distribution. In construction, proper assessment of grain size ensures the stability and drainage capacity of materials used in foundations, asphalt, or concrete. In natural environments, it influences erosion, sediment transport, and habitat formation.

The physical and chemical properties of sand are also affected by grain size. Smaller grains tend to hold more water and have higher surface area, impacting moisture retention and chemical reactivity. Conversely, coarser sands improve drainage and reduce water retention. Accurate knowledge of sandkörnung is essential for environmental management, engineering projects, and understanding geological processes.