Compressive strength is a measure of how much force a material or structure can withstand under a compressive load. It is measured by crushing a sample in a compression machine until the sample fails.

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The sample can be a cylinder or a cube, and is usually concrete, but grout, soils, and gravels are also tested for compressive strength.

 

Compressive strength is measured in megapascals (MPa), a measurement of pressure.

 

Pressure = Force applied over the surface Area of an object

 

Force is measured in kilonewtons (kN), with a load cell

Area is measured in cm², usually calculated from the diameters taken with vernier calipers

 

1 MPa is equal to 0.1kN/cm² (or about 10.2kg / cm²)

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Some examples of how much force it takes to crush samples: