Armourstone

For particular applications like a top layer for a breakwater or bank protection, the median stone mass size, known as M50, is frequently required.

It's worth noting that in wider ranges, notably 15-300 and 40-400, there's a considerable difference; for the 15-300 class, M50 is 1.57 times the MEM.

This naming convention exists because this class corresponds to the coarse category in the standard for fractional stone used as supplemental material (aggregate).

For the CP stone class, size isn't denoted in kg, but in mm.

Based on the primary data from standard EN13383, the following table is presented:[3] Several standards and guidelines are identified for classifying armourstone used in coastal and river engineering in the United States, some of which are summarised in the following table: These standards provide different methodologies for classifying armourstone, ranging from weight-based classifications to gradation curves and size-based classifications.

Guidance for the use of large armourstone is given in various USACE publications including the Coastal Engineering Manual.

[10][11][12] For fine-grained materials, such as sand, the size is typically represented by the median diameter.

Every stone's weight is individually recorded, and their masses are illustrated in the attached graph.

This visual misperception can be attributed to a few particularly large stones within the sample, which distort the overall impression.

This includes attributes like the shape parameter (measured as Length/Thickness), resistance to fracturing, and the capacity for water absorption.

For computations pertaining to stone weight in flows, the Izbash formula is advisable.