Degradation of construction materials - Revision history

Designing Buildings at 07:28, 24 March 2021

2021-03-24T07:28:47Z

← Older revision		Revision as of 07:28, 24 March 2021
Line 63:		Line 63:
	* Construction materials.		* Construction materials.
	* Defects.		* Defects.
		+	* Deterioration.
	* Dry rot.		* Dry rot.
	* Failure of cast iron beams.		* Failure of cast iron beams.

Designing Buildings at 07:42, 18 January 2021

2021-01-18T07:42:21Z

← Older revision		Revision as of 07:42, 18 January 2021
Line 80:		Line 80:
	BTEC National Construction Student Book, Pearson		BTEC National Construction Student Book, Pearson

−	[[Category:~~Products_/_components~~]] [[Category:~~DCN_Product_Knowledge~~]]	+	[[Category:DCN_Definition]] [[Category:DCN_Guidance]] [[Category:Products_/_components]]

Designing Buildings at 17:04, 23 March 2020

2020-03-23T17:04:11Z

← Older revision		Revision as of 17:04, 23 March 2020
Line 75:		Line 75:
	* Stain.		* Stain.
	* Structural failures.		* Structural failures.
−	* Stain.

	= External references =		= External references =
Line 81:		Line 80:
	BTEC National Construction Student Book, Pearson		BTEC National Construction Student Book, Pearson

−	[[Category:Products_/_components]]	+	[[Category:Products_/_components]] [[Category:DCN_Product_Knowledge]]

Designing Buildings at 17:02, 23 March 2020

2020-03-23T17:02:51Z

← Older revision		Revision as of 17:02, 23 March 2020
Line 69:		Line 69:
	* Hydrogen embrittlement.		* Hydrogen embrittlement.
	* Marine corrosion.		* Marine corrosion.
		+	* Meassures to minimise material degradation.
	* Mould growth in buildings.		* Mould growth in buildings.
	* Rust.		* Rust.

Designing Buildings at 17:02, 23 March 2020

2020-03-23T17:02:12Z

← Older revision		Revision as of 17:02, 23 March 2020
Line 52:		Line 52:
	= Chemical =		= Chemical =

−	All materials are generally susceptible to chemical degradation ~~and~~ can be caused by:	+	All materials are generally susceptible to chemical degradation. This can be caused by:

	* Alkalis – especially when alkaline cement paste and silica-based aggregates react and can cause cracking.		* Alkalis – especially when alkaline cement paste and silica-based aggregates react and can cause cracking.
Line 61:		Line 61:
	= Related articles on Designing Buildings Wiki =		= Related articles on Designing Buildings Wiki =

−	* Building Regulations.
	* Construction materials.		* Construction materials.
	* Defects.		* Defects.
	* Dry rot.		* Dry rot.
−	* ~~Materials on site~~.	+	* Failure of cast iron beams.
−	* ~~Quality control~~.	+	* Failure of metals.
		+	* Graphitisation.
		+	* Hydrogen embrittlement.
		+	* Marine corrosion.
		+	* Mould growth in buildings.
		+	* Rust.
	* Schedule of defects.		* Schedule of defects.
−	* ~~Testing construction materials~~.	+	* Stain.
−	* ~~Timber preservation~~.	+	* Structural failures.
−	* ~~Truth to materials~~.	+	* Stain.

	= External references =		= External references =

Designing Buildings at 16:58, 23 March 2020

2020-03-23T16:58:23Z

← Older revision		Revision as of 16:58, 23 March 2020
Line 1:		Line 1:
	= Introduction =		= Introduction =

−	~~Most construction~~ materials can be very durable but ~~it is known~~ of ~~cases where~~ building materials ~~have failed~~ prematurely. All building materials can suffer from deterioration and decay if they are not protected or maintained correctly. ~~Some common scenarios that can lead to~~ the degradation of construction materials ~~are~~:	+	Construction materials can be very durable but there are many cases of building materials failing prematurely. All building materials can suffer from deterioration and decay if they are not protected and maintained correctly. Common reasons for the degradation of construction materials include:

	* Natural agents.		* Natural agents.
Line 11:		Line 11:
	* Chemical.		* Chemical.

−	= Natural ~~Agents~~ =	+	= Natural agents =

−	Some materials can decay due to natural processes~~. Some of these processes can be~~:	+	Some materials can decay due to natural processes including:

	* Ageing- natural deterioration over time from wear and tear.		* Ageing- natural deterioration over time from wear and tear.
−	* Weather – exposure to the elements over time caused for instance by wind, frost, rain.	+	* Weather – exposure to the elements over time caused for instance by wind, frost and rain.
−	* Timber decay- including dry rot, insects, wet rot or fungal attacks.	+	* Timber decay- including dry rot, insects, wet rot and fungal attacks.
−	* Ultraviolet – radiation from sunlight exposure.	+	* Ultraviolet light – radiation from sunlight exposure.

	= Moisture =		= Moisture =

−	Moisture penetration can cause damage to wood fibres and materials ~~like~~ plaster, brickwork, concrete or stonework. Capillary action causes water to move through materials ~~that~~ can ~~cause~~ deterioration.	+	Moisture penetration can cause damage to wood fibres and materials such as plaster, brickwork, concrete and stonework. Capillary action causes water to move through materials and this can result in deterioration.

	= Shrinkage =		= Shrinkage =

−	Shrinkage generally occurs in timber. Freshly felled timber will contain ~~more water and~~ when used in construction it is likely to ~~later shrink~~ and ~~cause~~ cracks and gaps in the timber itself, especially in very dry areas. ~~Kiln~~-dried timber can expand when used in areas with high humidity. The best method to avoid the size changes in timber is to allow it to acclimatise to the conditions ~~where~~ it will be ~~installed first~~.	+	Shrinkage generally occurs in timber. Freshly felled timber will contain significant amounts of moisture, but when used in construction it is likely to dry and shrink, causing cracks and gaps in the timber itself, especially in very dry areas.
		+
		+	Conversely, kiln-dried timber can expand when used in areas with high humidity. The best method to avoid the size changes in timber is to allow it to acclimatise to the conditions in which it will be used, before installation.

	= Exposure conditions =		= Exposure conditions =
Line 32:		Line 34:
	Exposure conditions might include:		Exposure conditions might include:

−	* Weathering- combined action of the elements ~~like~~ rain, wind frost and sunlight.	+	* Weathering - the combined action of the elements, such as rain, wind, frost and sunlight.
−	* Thermal ageing- in high temperatures the chemical processes involved in material degradation can be accelerated.	+	* Thermal ageing - in high temperatures the chemical processes involved in material degradation can be accelerated.
−	* Humidity – extreme levels of humidity can have an ~~expedited~~ effect ~~of degradation~~ on materials.	+	* Humidity – extreme levels of humidity can have an expediting effect on the degradation of materials.

	= Corrosion in metals =		= Corrosion in metals =

−	Corrosion in metals ~~happens due to a~~ chemical ~~process~~ when the ~~material~~ is exposed to liquid. The most common is oxidation ~~that~~ causes rust in iron.	+	Corrosion in metals is the result of chemical processes, typically when the metal is exposed to liquid. The most common occurrence of corrosion in metals is oxidation, which causes rust in iron.

	= Loading =		= Loading =

Editor2 at 16:47, 16 March 2020

2020-03-16T16:47:34Z

← Older revision		Revision as of 16:47, 16 March 2020
Line 26:		Line 26:
	= Shrinkage =		= Shrinkage =

−	Shrinkage generally occurs in timber. Freshly felled timber will contain more water and when used in construction it is likely to later shrink and cause cracks and gaps in the timber itself especially in very dry areas. Kiln-dried timber can expand when used in areas with high humidity. The best method to avoid the ~~shrinkage or swelling of~~ timber is to allow ~~the timber~~ to acclimatise to the conditions where it will be installed.	+	Shrinkage generally occurs in timber. Freshly felled timber will contain more water and when used in construction it is likely to later shrink and cause cracks and gaps in the timber itself, especially in very dry areas. Kiln-dried timber can expand when used in areas with high humidity. The best method to avoid the size changes in timber is to allow it to acclimatise to the conditions where it will be installed first.

	= Exposure conditions =		= Exposure conditions =
Line 32:		Line 32:
	Exposure conditions might include:		Exposure conditions might include:

−	* Weathering- combined action of the elements like rain, wind frost and sunlight	+	* Weathering- combined action of the elements like rain, wind frost and sunlight.
−	* Thermal ageing- in high temperatures the chemical processes involved in material degradation can be accelerated	+	* Thermal ageing- in high temperatures the chemical processes involved in material degradation can be accelerated.
−	* Humidity – extreme levels of humidity can have an expedited effect of degradation on materials	+	* Humidity – extreme levels of humidity can have an expedited effect of degradation on materials.

	= Corrosion in metals =		= Corrosion in metals =
Line 44:		Line 44:
	Loading conditions causing degradation can be classified as:		Loading conditions causing degradation can be classified as:

−	* Shock – dynamic loads causing impact in low toughness materials	+	* Shock – dynamic loads causing impact in low toughness materials.
−	* Static – can cause creep deformation in materials over time	+	* Static – can cause creep deformation in materials over time.
−	* Cyclic – constant varying dynamic loading can cause fatigue in materials	+	* Cyclic – constant varying dynamic loading can cause fatigue in materials.

	= Chemical =		= Chemical =
Line 54:		Line 54:
	* Alkalis – especially when alkaline cement paste and silica-based aggregates react and can cause cracking.		* Alkalis – especially when alkaline cement paste and silica-based aggregates react and can cause cracking.
	* Sulphates – sulphates can be present in water and can react with concrete and cause levels of stress.		* Sulphates – sulphates can be present in water and can react with concrete and cause levels of stress.
−	* Leaching – some porous materials can be susceptible when minerals are dissolved in liquid solutions which will, in turn, weaken materials	+	* Leaching – some porous materials can be susceptible when minerals are dissolved in liquid solutions which will, in turn, weaken materials.
	* Acid rain – pollution in the atmosphere combines with water and forms acid rain. This rain can dissolve calcite in marble or limestone.		* Acid rain – pollution in the atmosphere combines with water and forms acid rain. This rain can dissolve calcite in marble or limestone.

Editor2: Created page with "= Introduction = Most construction materials can be very durable but it is known of cases where building materials have failed prematurely. All building materials can suffer fro..."

2020-03-16T10:44:34Z

Created page with "= Introduction = Most construction materials can be very durable but it is known of cases where building materials have failed prematurely. All building materials can suffer fro..."

New page

= Introduction =

Most construction materials can be very durable but it is known of cases where building materials have failed prematurely. All building materials can suffer from deterioration and decay if they are not protected or maintained correctly. Some common scenarios that can lead to the degradation of construction materials are:

* Natural agents.
* Moisture.
* Shrinkage.
* Exposure conditions.
* Corrosion in metals.
* Loading.
* Chemical.

= Natural Agents =

Some materials can decay due to natural processes. Some of these processes can be:

* Ageing- natural deterioration over time from wear and tear.
* Weather – exposure to the elements over time caused for instance by wind, frost, rain.
* Timber decay- including dry rot, insects, wet rot or fungal attacks.
* Ultraviolet – radiation from sunlight exposure.

= Moisture =

Moisture penetration can cause damage to wood fibres and materials like plaster, brickwork, concrete or stonework. Capillary action causes water to move through materials that can cause deterioration.

= Shrinkage =

Shrinkage generally occurs in timber. Freshly felled timber will contain more water and when used in construction it is likely to later shrink and cause cracks and gaps in the timber itself especially in very dry areas. Kiln-dried timber can expand when used in areas with high humidity. The best method to avoid the shrinkage or swelling of timber is to allow the timber to acclimatise to the conditions where it will be installed.

= Exposure conditions =

Exposure conditions might include:

* Weathering- combined action of the elements like rain, wind frost and sunlight
* Thermal ageing- in high temperatures the chemical processes involved in material degradation can be accelerated
* Humidity – extreme levels of humidity can have an expedited effect of degradation on materials

= Corrosion in metals =

Corrosion in metals happens due to a chemical process when the material is exposed to liquid. The most common is oxidation that causes rust in iron.

= Loading =

Loading conditions causing degradation can be classified as:

* Shock – dynamic loads causing impact in low toughness materials
* Static – can cause creep deformation in materials over time
* Cyclic – constant varying dynamic loading can cause fatigue in materials

= Chemical =

All materials are generally susceptible to chemical degradation and can be caused by:

* Alkalis – especially when alkaline cement paste and silica-based aggregates react and can cause cracking.
* Sulphates – sulphates can be present in water and can react with concrete and cause levels of stress.
* Leaching – some porous materials can be susceptible when minerals are dissolved in liquid solutions which will, in turn, weaken materials
* Acid rain – pollution in the atmosphere combines with water and forms acid rain. This rain can dissolve calcite in marble or limestone.

= Related articles on Designing Buildings Wiki =

* Building Regulations.
* Construction materials.
* Defects.
* Dry rot.
* Materials on site.
* Quality control.
* Schedule of defects.
* Testing construction materials.
* Timber preservation.
* Truth to materials.

= External references =

BTEC National Construction Student Book, Pearson

[[Category:Products_/_components]]