## Compressive strength |

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**Compressive strength** or **compression strength** is the capacity of a material or structure to withstand loads tending to reduce size, as opposed to

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 ^{[1]} Measurements of compressive strength are affected by the specific

- introduction
- deviation of engineering stress from true stress
- comparison of compressive and tensile strengths
- typical values
- compressive strength of concrete
- see also
- references

When a specimen of material is loaded in such a way that it extends it is said to be in *tension*. On the other hand, if the material *compression*.

On an atomic level, the molecules or

The "strain" is the relative change in length under applied stress; positive strain characterises an object under tension load which tends to lengthen it, and a compressive stress that shortens an object gives negative strain. Tension tends to pull small sideways deflections back into alignment, while compression tends to amplify such deflection into

Compressive strength is measured on materials, components,^{[2]} and structures.^{[3]}

By definition, the ultimate compressive strength of a material is that value of uniaxial *compressive test*. The apparatus used for this experiment is the same as that used in a tensile test. However, rather than applying a uniaxial tensile load, a uniaxial compressive load is applied. As can be imagined, the specimen (usually cylindrical) is shortened as well as spread laterally. A

The compressive strength of the material would correspond to the stress at the red point shown on the curve. In a compression test, there is a linear region where the material follows *, where, this time, E refers to the Young's Modulus for compression. In this region, the material deforms elastically and returns to its original length when the stress is removed.
*

This linear region terminates at what is known as the

There is a difference between the engineering stress and the true stress. By its basic definition the uniaxial stress is given by:

where,
F = Load applied [N],
A = Area [m^{2}]

As stated, the area of the specimen varies on compression. In reality therefore the area is some function of the applied load i.e. A = f(F). Indeed, stress is defined as the force divided by the area at the start of the experiment. This is known as the engineering stress and is defined by,

A_{0}=Original specimen area [m^{2}]

Correspondingly, the engineering

where
l = current specimen length [m] and l_{0} = original specimen length [m]

The compressive strength would therefore correspond to the point on the engineering stress strain curve defined by

where
F^{*} = load applied just before crushing and l^{*} = specimen length just before crushing.

Other Languages

العربية: مقاومة الانضغاط

català: Esforç de compressió

čeština: Pevnost v tlaku

dansk: Trykstyrke

Deutsch: Druckfestigkeit

eesti: Survetugevus

español: Esfuerzo de compresión

فارسی: مقاومت فشاری

français: Essai de compression

한국어: 압축강도

हिन्दी: संपीडन पुष्टि

Bahasa Indonesia: Kekuatan tekan

latviešu: Spiedes stiprība

Nederlands: Druksterkte

norsk: Trykkstyrke

norsk nynorsk: Trykkfastleik

polski: Ściskanie

português: Esforço de compressão

Simple English: Compressive strength

suomi: Puristuslujuus

தமிழ்: அமுக்க வலு

中文: 抗壓強度