Bulkstyrkan

Bulkstyrkan refers to the overall strength of a material when considered in its bulk form, as opposed to the properties of an idealized or single crystal. It describes the material's resistance to deformation and failure under loads applied to a macroscopic sample, integrating the influence of porosity, grain structure, defects, moisture, and temperature.

Practically, bulkstyrkan is commonly assessed through standard mechanical tests on bulk specimens. In solids, compressive or flexural strength tests on concrete, metal, or polymer specimens yield a bulk strength value. For powders and granular materials, bulk strength often relates to the unconfined compressive strength of a compacted mass or the shear strength measured in direct shear tests; moisture and compaction state significantly affect results.

Knowing bulkstyrkan helps engineers select materials and design components subjected to real-world, bulk loading. It is relevant in civil engineering (concrete, rock masses), geotechnical engineering (soil stability), pharmaceuticals and foods processing (powder flow and compaction), and materials science (composites and porous media).

It is distinct from tensile yield strength or tensile ultimate strength of a single crystal, and from the bulk modulus, which measures resistance to hydrostatic compression rather than failure.

The term appears in Swedish-language literature and some international texts as a descriptive phrase rather than a formal standardized quantity.