kompressionsstyrken

Kompressionsstyrken (compressive strength) is the capacity of a material to withstand axial compressive stress, i.e., stress that tends to shorten or crush the specimen. In Danish and Norwegian engineering usage, kompressionsstyrken is the term for this property. It is a fundamental material property used in designing structures and components that bear loads in compression.

Measurement is performed with a compression test on standardized specimens using a universal testing machine. A specimen—often a cylinder for concrete or a cube for bricks and ceramics—is loaded monotonically until failure. The maximum load divided by the cross-sectional area yields the compressive strength. Results are typically reported in megapascals (MPa) or pounds per square inch (psi). Conditioning, moisture state, temperature, and the rate of loading can influence the measured value.

Values vary widely by material. Ordinary concrete commonly exhibits compressive strengths around 20–40 MPa, with higher-performance concretes reaching substantially more. Ceramics and masonry materials are generally strong in compression, while some polymers and composites show high compressive strength relative to tension. Metals often display very high compressive strength, though their overall behavior depends on microstructure and loading conditions.

In design, kompressionsstyrken informs safety, bearing capacity, and serviceability. Building codes and standards specify minimum compressive strengths for materials and components and prescribe testing methods, specimen geometries, and conditioning. It is important to consider factors such as defect distribution, anisotropy, curing, and the interaction with reinforcement or bonding, as compressive strength alone does not fully predict real-world performance.