Compressive strength or compression strength is the capacity of a material or structure to withstand loads tending to reduce size, as opposed to tensile strength, which withstands loads tending to elongate. In other words, compressive strength resists compression (being pushed together), whereas tensile strength resists tension (being pulled apart). In the study of strength of materials, tensile strength, compressive strength, and shear strength can be analyzed independently.
Some materials fracture at their compressive strength limit; others deform irreversibly, so a given amount of deformation may be considered as the limit for compressive load. Compressive strength is a key value for design of structures.
Compressive strength is often measured on a universal testing machine; these range from very small table-top systems to ones with over 53 MN capacity.Measurements of compressive strength are affected by the specific test method and conditions of measurement. Compressive strengths are usually reported in relationship to a specific technical standard.
Selected Test Standards
- ASTM D575 Compression Test of Rubber
- ASTM D6641 Compression Testing for Polymer Matrix Composite Laminates
- ASTM D695 Compression Testing for Rigid Plastics
- ASTM D7137 Compressive Residual Strength Test Equipment for Damaged Polymer Matrix Composite Plates
- ASTM D905 Wood Adhesive Bonds in Shear by Compression Loading
- ASTM E9 Compression Testing of Metallic Materials at Room Temperature
- ISO 14126 Compression Fiber-Reinforced Plastic Composites Test Machine
- ISO 1856 Flexible Cellular Polymeric Materials Compression EN
- ISO 604 Compressive Plastics Testing Equipment
- ISO 844 Compressive Strength of Rigid Cellular Plastics