Compressive strength - Revision history

Editor at 18:06, 26 January 2022

2022-01-26T18:06:49Z

← Older revision		Revision as of 18:06, 26 January 2022
Line 28:		Line 28:
	It is sometimes difficult to measure the compressive strength of ductile metals, such as mild steel, which have high compressive strengths. This is due to the failure mode of such materials. Typically, under a compressive load, mild steel deforms elastically up to a point; this is followed by plastic deformation and ultimately the specimen may be flattened without significant evidence of fracture. It can therefore be difficult to measure the precise point of compressive failure. For this reason, it is more common to quote the tensile strength of mild steel which is easier to obtain; as its tensile strength is always lower than its compressive strength, it can be used as the basis for calculations.		It is sometimes difficult to measure the compressive strength of ductile metals, such as mild steel, which have high compressive strengths. This is due to the failure mode of such materials. Typically, under a compressive load, mild steel deforms elastically up to a point; this is followed by plastic deformation and ultimately the specimen may be flattened without significant evidence of fracture. It can therefore be difficult to measure the precise point of compressive failure. For this reason, it is more common to quote the tensile strength of mild steel which is easier to obtain; as its tensile strength is always lower than its compressive strength, it can be used as the basis for calculations.

−	= Related articles on Designing Buildings ~~Wiki~~ =	+	= Related articles on Designing Buildings =

	* Arch.		* Arch.
Line 45:		Line 45:
	* Superstructure.		* Superstructure.
	* Tower.		* Tower.
		+	* Tensile strength.
	* Tension.		* Tension.
	* Types of structure.		* Types of structure.

Editor at 18:26, 26 February 2021

2021-02-26T18:26:12Z

← Older revision		Revision as of 18:26, 26 February 2021
Line 47:		Line 47:
	* Tension.		* Tension.
	* Types of structure.		* Types of structure.
		+	* Voussoir.

	[[Category:DCN_Definition]] [[Category:DCN_Guidance]] [[Category:Theory]]		[[Category:DCN_Definition]] [[Category:DCN_Guidance]] [[Category:Theory]]

Designing Buildings at 08:24, 27 December 2020

2020-12-27T08:24:24Z

← Older revision		Revision as of 08:24, 27 December 2020
Line 48:		Line 48:
	* Types of structure.		* Types of structure.

−	[[Category:Theory]]	+	[[Category:DCN_Definition]] [[Category:DCN_Guidance]] [[Category:Theory]]

Editor at 12:24, 3 February 2020

2020-02-03T12:24:05Z

← Older revision		Revision as of 12:24, 3 February 2020
Line 32:		Line 32:
	* Arch.		* Arch.
	* Barrel vault.		* Barrel vault.
		+	* Compressive strength of timber lattice columns for low-rise construction.
	* Concrete.		* Concrete.
	* Dome.		* Dome.

Editor at 19:26, 30 January 2020

2020-01-30T19:26:41Z

← Older revision		Revision as of 19:26, 30 January 2020
Line 37:		Line 37:
	* Engineer.		* Engineer.
	* Flying buttress.		* Flying buttress.
		+	* Mass concrete.
	* Steel.		* Steel.
	* Structural engineer.		* Structural engineer.

Designing Buildings at 12:25, 15 October 2019

2019-10-15T12:25:23Z

← Older revision		Revision as of 12:25, 15 October 2019
Line 20:		Line 20:
	* The compressive force applied at the time of failure (defined as permanent deformation - ie an inability to assume its former shape once the compressive force is removed).		* The compressive force applied at the time of failure (defined as permanent deformation - ie an inability to assume its former shape once the compressive force is removed).

−	Once these measurements are available, the compressive strength (C) can be calculated as:	+	Once these measurements are available, the compressive strength (C or σc) can be calculated as:

	== C = F/A ==		== C = F/A ==

−	where F is the maximum force (load) applied at the point of failure and A is the cross-sectional area of the specimen before the force was applied.	+	where F is the maximum force (load) applied at the point of failure and A is the cross-sectional area of the specimen before the force was applied. It can be expressed in terms of N/m² or Pascals (where 1 Pascal (Pa) = 1 N/m²).

	It is sometimes difficult to measure the compressive strength of ductile metals, such as mild steel, which have high compressive strengths. This is due to the failure mode of such materials. Typically, under a compressive load, mild steel deforms elastically up to a point; this is followed by plastic deformation and ultimately the specimen may be flattened without significant evidence of fracture. It can therefore be difficult to measure the precise point of compressive failure. For this reason, it is more common to quote the tensile strength of mild steel which is easier to obtain; as its tensile strength is always lower than its compressive strength, it can be used as the basis for calculations.		It is sometimes difficult to measure the compressive strength of ductile metals, such as mild steel, which have high compressive strengths. This is due to the failure mode of such materials. Typically, under a compressive load, mild steel deforms elastically up to a point; this is followed by plastic deformation and ultimately the specimen may be flattened without significant evidence of fracture. It can therefore be difficult to measure the precise point of compressive failure. For this reason, it is more common to quote the tensile strength of mild steel which is easier to obtain; as its tensile strength is always lower than its compressive strength, it can be used as the basis for calculations.

Designing Buildings at 12:20, 15 October 2019

2019-10-15T12:20:13Z

Editor at 16:11, 8 October 2019

2019-10-08T16:11:13Z

← Older revision		Revision as of 16:11, 8 October 2019
Line 6:		Line 6:

	Some materials are better than others at withstanding compression before failure occurs. Steel can withstand relatively high compressive forces; stone and unreinforced concrete cannot. Other materials, such as concrete and ceramics, typically show much higher compressive strengths than tensile strengths. Depending on the material, failure can comprise fracture at the compressive strength limit or irreversible deformation.		Some materials are better than others at withstanding compression before failure occurs. Steel can withstand relatively high compressive forces; stone and unreinforced concrete cannot. Other materials, such as concrete and ceramics, typically show much higher compressive strengths than tensile strengths. Depending on the material, failure can comprise fracture at the compressive strength limit or irreversible deformation.
−
−	~~Typical average ultimate compressive strengths of common building materials:~~
−
−	~~Hard bricks 80MPa~~
−
−	~~Granite 130Mpa~~
−
−	~~Concrete (28 days old) 35MPa~~

	Materials which can resist high, applied compressive forces before failure are said to have high compressive strengths, and vice versa. Compressive strength can also be measured on components. For concrete, compressive strength is the most common performance measurement used by engineers in the design of buildings.		Materials which can resist high, applied compressive forces before failure are said to have high compressive strengths, and vice versa. Compressive strength can also be measured on components. For concrete, compressive strength is the most common performance measurement used by engineers in the design of buildings.

−	Measuring compressive strength	+	= Measuring compressive strength =

−	It is possible to measure precisely the compressive strength of materials by conducting a compressive test under carefully controlled conditions using a universal testing machine. This can typically have testing capacities of up to 53 mega Newtons (MN) which is equal to a ~~ton-force of~~ 5,~~404tnf~~.	+	It is possible to measure precisely the compressive strength of materials by conducting a compressive test under carefully controlled conditions using a universal testing machine. This can typically have testing capacities of up to 53 mega Newtons (MN) which is equal to a 5,404 ton force.

	In building construction, testing the compressive strength of concrete is usually undertaken at different stages after it has been poured in order to allow sufficient time for strength development (eg after 28 days). Typically, a cube (or cylinder) of concrete is usually used as a test specimen, ensuring that the top and bottom surfaces are flat and parallel, and that both faces are a perfect cross-section, ie, at right angles to the vertical axis of the cube.		In building construction, testing the compressive strength of concrete is usually undertaken at different stages after it has been poured in order to allow sufficient time for strength development (eg after 28 days). Typically, a cube (or cylinder) of concrete is usually used as a test specimen, ensuring that the top and bottom surfaces are flat and parallel, and that both faces are a perfect cross-section, ie, at right angles to the vertical axis of the cube.
Line 32:		Line 24:
	Once these measurements are available, the compressive strength (C) can be calculated as:		Once these measurements are available, the compressive strength (C) can be calculated as:

−	C = F/A	+	== C = F/A ==

	where F is the maximum force (load) applied at the point of failure and A is the cross-sectional area of the specimen before the force was applied.		where F is the maximum force (load) applied at the point of failure and A is the cross-sectional area of the specimen before the force was applied.

Editor: Created page with "Materials used for structural purposes are usually classified according to their resistance to basic stresses such as compression, tension and shear. Compression is a force that..."

2019-10-08T16:05:30Z

Created page with "Materials used for structural purposes are usually classified according to their resistance to basic stresses such as compression, tension and shear. Compression is a force that..."

New page

Materials used for structural purposes are usually classified according to their resistance to basic stresses such as compression, tension and shear.

Compression is a force that pushes the particles of a material closer together. For example, when a column supports a load, it is under compression and its height shortens, albeit imperceivably. The opposite is tensile force which tends to elongate the material.

All materials can, to a certain degree, withstand compressive forces before they fail (or fracture) and it is at this point that compressive strength is measured. Therefore, the compressive strength of a material is usually stated as the maximum compression that the material can stand before failure.

Some materials are better than others at withstanding compression before failure occurs. Steel can withstand relatively high compressive forces; stone and unreinforced concrete cannot. Other materials, such as concrete and ceramics, typically show much higher compressive strengths than tensile strengths. Depending on the material, failure can comprise fracture at the compressive strength limit or irreversible deformation.

Typical average ultimate compressive strengths of common building materials:

Hard bricks 80MPa

Granite 130Mpa

Concrete (28 days old) 35MPa

Materials which can resist high, applied compressive forces before failure are said to have high compressive strengths, and vice versa. Compressive strength can also be measured on components. For concrete, compressive strength is the most common performance measurement used by engineers in the design of buildings.

Measuring compressive strength

It is possible to measure precisely the compressive strength of materials by conducting a compressive test under carefully controlled conditions using a universal testing machine. This can typically have testing capacities of up to 53 mega Newtons (MN) which is equal to a ton-force of 5,404tnf.

In building construction, testing the compressive strength of concrete is usually undertaken at different stages after it has been poured in order to allow sufficient time for strength development (eg after 28 days). Typically, a cube (or cylinder) of concrete is usually used as a test specimen, ensuring that the top and bottom surfaces are flat and parallel, and that both faces are a perfect cross-section, ie, at right angles to the vertical axis of the cube.

A compressive force is applied to the specimen gradually by the testing mechanism. Measuring the compressive strength using this method requires:

* The cross-sectional area of one of the cube’s faces, top or bottom (they should be identical), and
* The compressive force applied at the time of failure (defined as permanent deformation*).

(Permanent deformation of a specimen is defined as an inability to assume its former shape once the compressive force is removed).

Once these measurements are available, the compressive strength (C) can be calculated as:

C = F/A

where F is the maximum force (load) applied at the point of failure and A is the cross-sectional area of the specimen before the force was applied.

It is sometimes difficult to measure the compressive strength of ductile metals, such as mild steel, which have high compressive strengths. This is due to the failure mode of such materials. Typically, under a compressive load, mild steel deforms elastically up to a point; this is followed by plastic deformation and ultimately the specimen may be flattened without significant evidence of fracture. It can therefore be difficult to measure the precise point of compressive failure. For this reason, it is more common to quote the tensile strength of mild steel which is easier to obtain; as its tensile strength is always lower than its compressive strength, it can be used as the basis for calculations.

= Related articles on Designing Buildings Wiki =

* Arch.
* Barrel vault.
* Concrete.
* Dome.
* Elements of structure in buildings
* Engineer.
* Flying buttress.
* Steel.
* Structural engineer.
* Structural principles.
* Substructure.
* Superstructure.
* Tower.
* Tension.
* Types of structure.

[[Category:Theory]]

← Older revision		Revision as of 12:20, 15 October 2019
Line 1:		Line 1:
	Materials used for structural purposes are usually classified according to their resistance to basic stresses such as compression, tension and shear.		Materials used for structural purposes are usually classified according to their resistance to basic stresses such as compression, tension and shear.

−	Compression is a force that pushes the particles of a material closer together. For example, when a column supports a load, it is under compression and its height shortens, albeit imperceivably. The opposite is tensile force which tends to elongate ~~the~~ material.	+	Compression is a force that pushes the particles of a material closer together. For example, when a column supports a load, it is under compression and its height shortens, albeit often imperceivably. The opposite is tensile force which tends to elongate a material.

−	All materials can, to a certain degree, withstand compressive forces before they fail ~~(or fracture)~~ and it is at this point that compressive strength is measured. Therefore, the compressive strength of a material is usually stated as the maximum compression that the material can stand before failure.	+	All materials can, to a certain degree, withstand compressive forces before they fail and it is at this point that compressive strength is measured. Therefore, the compressive strength of a material is usually stated as the maximum compression that the material can stand before failure.

−	~~Some materials are better than others at withstanding compression before failure occurs. Steel~~ can ~~withstand relatively~~ high compressive forces~~; stone and unreinforced concrete cannot. Other materials, such as concrete and ceramics, typically show much higher~~ compressive strengths ~~than tensile strengths. Depending on the material, failure can comprise fracture at the compressive strength limit or irreversible deformation~~.	+	Materials which can resist high, applied compressive forces before failure are said to have high compressive strengths.

−	~~Materials which can resist high, applied compressive forces~~ before failure ~~are said to have~~ high compressive ~~strengths~~, and ~~vice versa~~. ~~Compressive strength can also be measured~~ on ~~components. For concrete~~, compressive strength ~~is the most common performance measurement used by engineers in the design of buildings~~.	+	Some materials are better than others at withstanding compression before failure occurs. Steel can withstand relatively high compressive forces. Other materials, such as concrete and ceramics, typically show much higher compressive strengths than tensile strengths. Depending on the material, failure can comprise fracture at the compressive strength limit or irreversible deformation.

	= Measuring compressive strength =		= Measuring compressive strength =
Line 13:		Line 13:
	It is possible to measure precisely the compressive strength of materials by conducting a compressive test under carefully controlled conditions using a universal testing machine. This can typically have testing capacities of up to 53 mega Newtons (MN) which is equal to a 5,404 ton force.		It is possible to measure precisely the compressive strength of materials by conducting a compressive test under carefully controlled conditions using a universal testing machine. This can typically have testing capacities of up to 53 mega Newtons (MN) which is equal to a 5,404 ton force.

−	In building construction, testing the compressive strength of concrete is usually undertaken at different stages after it has been poured in order to allow sufficient time for strength development (eg after 28 days). Typically, a cube (or cylinder) of concrete is ~~usually~~ used as a test specimen, ensuring that the top and bottom surfaces are flat and parallel, and that both faces are a perfect cross-section, ie, at right angles to the vertical axis of the cube.	+	In building construction, testing the compressive strength of concrete is usually undertaken at different stages after it has been poured in order to allow sufficient time for strength development (eg after 28 days). Typically, a cube (or cylinder) of concrete is used as a test specimen, ensuring that the top and bottom surfaces are flat and parallel, and that both faces are a perfect cross-section, ie, at right angles to the vertical axis of the cube.

	A compressive force is applied to the specimen gradually by the testing mechanism. Measuring the compressive strength using this method requires:		A compressive force is applied to the specimen gradually by the testing mechanism. Measuring the compressive strength using this method requires:

	* The cross-sectional area of one of the cube’s faces, top or bottom (they should be identical), and		* The cross-sectional area of one of the cube’s faces, top or bottom (they should be identical), and
−	* The compressive force applied at the time of failure (defined as permanent deformation*).	+	* The compressive force applied at the time of failure (defined as permanent deformation - ie an inability to assume its former shape once the compressive force is removed).
−		+
−	~~(Permanent deformation of a specimen is defined as~~ an inability to assume its former shape once the compressive force is removed).	+

	Once these measurements are available, the compressive strength (C) can be calculated as:		Once these measurements are available, the compressive strength (C) can be calculated as: