FACTOID # 15: A mere 0.8% of West Virginians were born in a foreign country.
 
 Home   Encyclopedia   Statistics   States A-Z   Flags   Maps   FAQ   About 
 
WHAT'S NEW
RELATED ARTICLES
People who viewed "Plaster" also viewed:
 

SEARCH ALL

FACTS & STATISTICS    Advanced view

Search encyclopedia, statistics and forums:

 

 

(* = Graphable)

 

 


Encyclopedia > Plaster
Gypsum-based plaster used in spray fireproofing in a low-rise industrial building in Vancouver, British Columbia.
Gypsum-based plaster used in spray fireproofing in a low-rise industrial building in Vancouver, British Columbia.

Plaster of Paris, or simply plaster, is a type of building material based on calcium sulfate hemihydrate, nominally CaSO4·0.5H2O. It is created by heating gypsum to about 150 °C. Typical adhesive bandage Reverse of an adhesive bandage Opened adhesive bandage, showing the non-adhesive absorbent pad and adhesive An adhesive bandage (called a sticking plaster, just plaster, or Elastoplast (a trademark) in the United Kingdom, New Zealand, Malaysia, Singapore, and South Africa; often called Band-Aid (a trademark) generically... Image File history File links Fireproofing. ... Image File history File links Fireproofing. ... For other uses, see Gypsum (disambiguation). ... Fireproofing, a passive fire protection measure, subject to bounding, refers to the act of making materials or structures more resistant to fire, or to those materials themselves. ... Old Executive Office Building, Washington D.C. Bank of China Tower, Hong Kong, China In architecture, construction, engineering and real estate development the word building may refer to one of the following: Any man-made structure used or intended for supporting or sheltering any use or continuous occupancy, or An... For other uses, see Vancouver (disambiguation). ... Motto: Splendor sine occasu (Latin: Splendour without diminishment) Capital Victoria Largest city Vancouver Official languages English (de facto) Government Lieutenant-Governor Steven Point Premier Gordon Campbell (BC Liberal) Federal representation in Canadian Parliament House seats 36 Senate seats 6 Confederation July 20, 1871 (6th province) Area  Ranked 5th Total 944... Calcium sulphate is a common laboratory and industrial chemical. ... For other uses, see Gypsum (disambiguation). ...

2 CaSO4·2H2O → 2 CaSO4·0.5H2O + 3 H2O (released as steam).

A large gypsum deposit at Montmartre in Paris is the source of the name.[1] When the dry plaster powder is mixed with water, it re-forms into gypsum. Plaster is used as a building material similar to mortar or cement. Like those materials plaster starts as a dry powder that is mixed with water to form a paste which liberates heat and then hardens. Unlike mortar and cement, plaster remains quite soft after drying, and can be easily manipulated with metal tools or even sandpaper. These characteristics make plaster suitable for a finishing, rather than a load-bearing material. Montmartre seen from the centre Georges Pompidou (1897), a painting by Camille Pissarro of the boulevard that led to Montmartre as seen from his hotel room. ... This article is about the capital of France. ... Mortar holding weathered bricks. ... For other uses, see Cement (disambiguation). ... Mortar holding weathered bricks. ... For other uses, see Cement (disambiguation). ... sheets of sandpaper Sandpaper is a form of paper where an abrasive material has been fixed to its surface; it is part of the coated abrasives family of abrasive products. ...


Plaster was a common building material for wall surfaces in a process known as lath and plaster, whereby a series of wooden strips are covered with a semi-dry plaster and then hardened into surface. The plaster used in most lath-and-plaster construction was mainly lime plaster. Lime plaster cure time is about a month. To stabilize the lime plaster during curing, small amounts of Plaster of Paris were mixed into the putty. Because Plaster of Paris sets quickly, "retardants" were used to slow setting time enough to allow workers to mix large working quantities of lime putty plaster. A modern form of this method uses expanded metal mesh over wood or metal structures, which allows a great freedom of design as it is adaptable to both simple and compound curves. Today this building method has been partly replaced with drywall, also composed mostly of gypsum plaster. In both these methods a primary advantage of the material is that it is resistant to a fire within a room and so can assist in reducing or eliminating structural damage or destruction provided the fire is promptly extinguished. For other uses, see Construction (disambiguation). ...


One of the skills used in movie and theatrical sets is that of "plasterer", and the material is often used to simulate the appearance of surfaces of wood, stone, or metal. Nowadays, plasterers are just as likely to use expanded polystyrene, although the job title remains unchanged.

Contents

Use in architecture

19th century plasterwork from House of Borujerdies in Kashan, Iran.
19th century plasterwork from House of Borujerdies in Kashan, Iran.

Plaster may also be used to create complex detailing for use in room interiors. These may be geometric (simulating wood or stone) or naturalistic (simulating leaves, vines, and flowers) These are also often used to simulate wood or stone detailing found in more substantial buildings. Image File history File links Gachbori_kashan. ... Image File history File links Gachbori_kashan. ... A view of the house. ... Tabatabaei House, early 1800s, Kashan. ...

Use in the arts

See also: Plaster cast

Many of the greatest paintings in Europe, like Michelangelo's Sistine Chapel ceiling are executed in Fresco, meaning they are painted on a thin layer of wet plaster, called intonaco (in fact the general term for plaster in Italian); the pigments sink into this layer so that the plaster itself becomes the medium holding them, which accounts for the excellent durability of fresco. Additional work may be added a secco on top of the dry plaster, though this is generally less durable. This page describe terms and jargon related to sculpture and sculpting. ... The iconic image of the Hand of God giving life to Adam. ... For other uses, see Fresco (disambiguation). ... Categories: Possible copyright violations ...


Plaster may be cast directly into a damp clay mold. In creating this moldmolds (molds designed for making multiple copies) or waste molds (for single use) would be made of plaster. This "negative" image, if properly designed, may be used to produce clay productions, which when fired in a kiln become terra cotta building decorations, or these may be used to create cast concrete sculptures. If a plaster positive was desired this would be constructed or cast to form a durable image artwork. As a model for stonecutters this would be sufficient. If intended for producing a bronze casting the plaster positive could be further worked to produce smooth surfaces. An advantage of this plaster image is that it is relatively cheap; should a patron approve of the durable image and be willing to bear further expense, subsequent molds could be made for the creation of a wax image to be used in lost wax casting, a far more expensive process. In lieu of producing a bronze image suitable for outdoor use the plaster image may be painted to resemble a metal image; such sculptures are suitable only for presentation in a weather-protected environment. Terra cotta is a hard semifired waterproof ceramic clay used in pottery and building construction. ... This article is about the construction material. ... This article is about the manufacturing process. ...

Example of a stenciled plaster design
Example of a stenciled plaster design

Plaster expands while hardening, then contracts slightly just before hardening completely. This makes plaster excellent for use in molds, and it is often used as an artistic material for casting. Plaster is also commonly spread over an armature (form), usually made of wire, mesh or other materials. Image File history File links No higher resolution available. ... Image File history File links No higher resolution available. ...


Plaster is often used in Faux Finishing to create textures for wall and furniture surfaces, as in Venetian Plaster and also in stenciling for raised details. For these processes, artists use limestone based plasters or new user friendly acrylic based plaster. Faux finishing or faux marbling is the preparation and finishing of a surface to imitate the appearance of polished marble. ... Venetian Plaster is a Faux Painting or Faux Finishing technique using thin layers of plaster applied with a spatula or trowel and then burnished to create a smooth surface with the illusion of depth and texture. ...


Use in medicine

Plaster is widely used as a support for broken bones; a bandage impregnated with plaster is moistened and then wrapped around the damaged limb, setting into a close-fitting yet easily removed tube, known as a Cast (orthopedic) cast; however, this is slowly being replaced by a fibreglass variety.


Plaster is also used within radiotherapy when making immobilisation casts for patients. Plaster bandages are used when constructing an impression of the patients head and neck, and liquid plaster is used to fill the impression and produce a plaster bust. Perspex is then vacuum formed over this bust creating an immobilisation shell.


In dentistry, plaster is used for mounting casts or models of oral tissues. These diagnostic and working models are usually made from dental stone, a stronger, harder and denser derivative of plaster which is manufactured from gypsum under pressure. Plaster is also used to invest or flask wax dentures, the wax being subsequently removed and replaced with the final denture base material which is cured in the plaster mold.


Lime plaster

Lime plaster is a mixture of calcium hydroxide and sand (or other inert fillers). Carbon dioxide in the atmosphere causes the plaster to set by transforming the calcium hydroxide into calcium carbonate (limestone). Whitewash is based on the same chemistry. For other uses, see Limestone (disambiguation). ... Whitewash, or calcimine, kalsomine, or calsomine is a type of inexpensive paint made from slaked lime (calcium hydroxide) and chalk (whiting). ...


To make lime plaster, Limestone (calcium carbonate) is heated to produce quicklime (calcium oxide). Water is then added to produce slaked lime (calcium hydroxide), which is sold as a white powder. Additional water is added to form a paste prior to use. The paste may be stored in air-tight containers. Once exposed to the atmosphere, the calcium hydroxide turns back into limestone, causing the plaster to set. For other uses, see Limestone (disambiguation). ... Calcium oxide (CaO), commonly known as lime or quicklime, is a widely used chemical compound. ... Calcium hydroxide is a chemical compound with the chemical formula Ca(OH)2. ...


Lime plaster is used for true frescoes. Pigments, diluted in water, are applied to the still wet plaster. For other uses, see Fresco (disambiguation). ... Natural Ultramarine pigment in powdered form. ...


Cement plaster

Cement plaster is a mixture of suitable plaster sand, portland cement and water which is normally applied to masonry interiors and exteriors to achieve a smooth surface. Interior surfaces sometimes receive a final layer of gypsum plaster. Walls constructed with stock bricks are normally plastered while face brick walls are not plastered. Various cement-based plasters are also used as proprietary spray fireproofing products, the world over. These usually use vermiculite as lightweight aggregate. Heavy versions of such plasters are also in use for exterior fireproofing, to protect LPG vessels, pipe bridges and vessel skirts. Sampling fast set Portland cement Portland cement is the most common type of cement in general usage, as it is a basic ingredient of concrete, mortar and plaster. ... London stock brick is the most commonly used type of building brick used in London. ... Flemish bond. ... Fireproofing, a passive fire protection measure, subject to bounding, refers to the act of making materials or structures more resistant to fire, or to those materials themselves. ... Vermiculite is a natural, non toxic mineral that expands with the application of heat. ...


Passive fire protection

Plasters have been in use in passive fire protection, as fireproofing products, for many decades. Fire-resistance rated wall assembly with fire door, cable tray penetration and intumescent [1] cable coating. ... Fireproofing, a passive fire protection measure, subject to bounding, refers to the act of making materials or structures more resistant to fire, or to those materials themselves. ...


The plaster provides a layer of insulation to retard heat flow into structural steel elements, that would otherwise lose their strength and collapse in a fire. Early versions of these plasters have used asbestos fibres, which have by now been outlawed in industrialised nations and have caused significant removal and re-coating work. More modern plasters fall into the following categories: Wikimedia Commons has media related to: Thermal insulation Thermal insulation on the Huygens probe Rockwool Insulation, 1600 dpi scan against the grain Rockwool Insulation, 1600 dpi scan with the grain The term thermal insulation can refer to materials used to reduce the rate of heat transfer, or the methods and... For other uses, see Heat (disambiguation) In physics, heat, symbolized by Q, is energy transferred from one body or system to another due to a difference in temperature. ... Structural steel is steel construction material, a profile, formed with a specific shape or cross section and certain standards of chemical composition and strength. ... For other uses, see Asbestos (disambiguation). ... Structures containing asbestos are marked Weathering of fibrous asbestos sheeting showing loose fibres. ...

  • fibrous (including mineral wool)
  • cement mixtures either with mineral wool or with vermiculite
  • gypsum plasters, leavened with polystyrene beads, as well as chemical expansion agents to decrease the density of the finished product

One differentiates between interior and exterior fireproofing. Interior products are typically less substantial, with lower densities and lower cost. Exterior products have to withstand more extreme fire and other environmental conditions. Exterior products are also more likely to be attractively tooled, whereas their interior cousins are usually merely sprayed in place. A rough surface is typically forgiven inside of buildings as dropped ceilings often hide them. Exterior fireproofing plasters are losing ground to more costly intumescent and endothermic products, simply on technical merit. Trade jurisdiction on unionised construction sites in North America remains with the plasterers, regardless of whether the plaster is decorative in nature or is used in passive fire protection. Cementitious and gypsum based plasters tend to be endothermic. Fireproofing plasters are closely related to firestop mortars. In fact, most firestop mortars can be sprayed and tooled very well, due to the fine detail work that is required of firestopping, which leads their mix designers to utilise concrete addmixtures, that enable easier tooling than common mortars. Mineral wool, means fibres made from minerals or metal oxides, be they synthetic or natural. ... Vermiculite is a natural, non toxic mineral that expands with the application of heat. ... For other uses, see Polystyrene (disambiguation). ... An intumescent is a substance which swells as a result of heat exposure, thus increasing in volume, and decreasing in density. ... This article is about the physical effect. ... North American redirects here. ... This article is about the physical effect. ... Firestop after fire exposure during fire test in Tulsa, Oklahoma. ... This article is about the construction material. ...


Trade jurisdiction

In unionized construction sites in North America, plaster is installed by contractors signatory to the Operative Plasterers’ and Cement Masons’ International Association (OPCMIA), which represents unionized plasterers. The Operative Plasterers and Cement Masons International Association of the United States and Canada is a labor union that represents plasterers and cement masons in the construction industry in North America. ... Plasterwork, or plastering, is one of the most ancient of handicrafts employed in connection with building operations, the earliest evidence showing that the dwellings of primitive man were erected in a simple fashion with sticks and plastered with mud. ...


Safety issues

The chemical reaction that occurs when plaster is mixed with water is exothermic in nature. The danger of this was illustrated in January 2007, when a sixteen-year-old girl suffered third-degree burns after encasing her hands in plaster as part of a school art project in Lincolnshire, England. She subsequently had her thumbs and most of her fingers amputated.[2] In place of plaster, alginate should be used for casting body parts. In thermodynamics, the word exothermic outside heating describes a process or reaction that releases energy usually in the form of heat, but it can also release energy in form of light (e. ... Students in Rome, Italy. ... This article is about the philosophical concept of Art. ... For other places with the same name, see Lincolnshire (disambiguation). ... For other uses, see England (disambiguation). ... Alginate is a linear copolymer with homopolymeric blocks of (1-4)-linked ß-D-mannuronate (M) and its C-5 epimer α-L-guluronate (G) residues, respectively, covalently linked together in different sequences or blocks. ...


Some variations of plaster that contain powdered silica or asbestos may present health hazards if inhaled. Asbestos is a known carcinogen when inhaled in powder form, especially in people who smoke, and inhalation can also cause asbestosis. Inhaled silica can cause silicosis and (in very rare cases) can encourage the development of cancer. Persons working regularly with plaster containing these additives should take precautions to avoid inhaling powdered plaster, cured or uncured. (Note that asbestos is rarely used in modern plaster formulations because of its carcinogenic effects.) The chemical compound silicon dioxide, also known as silica, is the oxide of silicon, chemical formula SiO2. ... For other uses, see Asbestos (disambiguation). ... Look up carcinogen in Wiktionary, the free dictionary. ... Asbestosis is a chronic inflammatory medical condition affecting the parenchymal tissue of the lungs. ... Silicosis (also known as Grinders disease) is a form of pneumoconiosis caused by inhalation of crystalline silica dust, and is marked by inflammation and scarring in forms of nodular lesions in the upper lobes of the lungs. ... Cancer is a class of diseases or disorders characterized by uncontrolled division of cells and the ability of these to spread, either by direct growth into adjacent tissue through invasion, or by implantation into distant sites by metastasis (where cancer cells are transported through the bloodstream or lymphatic system). ...


Illegal Uses

Plaster of Paris has been used illegally by some professional boxers in the past, such as Luis Resto. It makes a boxer's taped hands harder. For Luis Resto the boxer, see Luis Resto (boxer). ...


See also

Look up Plaster in
Wiktionary, the free dictionary.

Wiktionary (a portmanteau of wiki and dictionary) is a multilingual, Web-based project to create a free content dictionary, available in over 151 languages. ... The Cast Courts of the Victoria and Albert Museum in London, comprise two large halls. ... This article is about the physical effect. ... Fireproofing, a passive fire protection measure, subject to bounding, refers to the act of making materials or structures more resistant to fire, or to those materials themselves. ... Firestop after fire exposure during fire test in Tulsa, Oklahoma. ... The International Union of Bricklayers and Allied Craftworkers (often known by the acronym BAC) is a labor union in the United States and Canada which represents bricklayers, stone and marble masons, cement masons, plasterers, tilesetters, terrazzo and mosaic workers, and pointers/cleaners/caulkers. ... An intumescent is a substance which swells as a result of heat exposure, thus increasing in volume, and decreasing in density. ... Categories: Possible copyright violations ... Joint compound is a white substance similar to plaster used to seal joints between sheets of drywall, primarily in building construction. ... For other uses, see Limestone (disambiguation). ... Fire-resistance rated wall assembly with fire door, cable tray penetration and intumescent [1] cable coating. ... Pargeting is a decorative plastering applied to building walls. ... Plasterwork refers to construction or ornamentation done with plaster, such as a layer of plaster on an interior wall or plaster decorative moldings on ceilings or walls. ... This article does not cite any references or sources. ... Joint compound is a white substance similar to plaster used to seal joints between sheets of drywall, primarily in building construction. ... Stucco is a material made of an aggregate, a binder, and water which is applied wet, and hardens when it dries. ... Venetian Plaster is a Faux Painting or Faux Finishing technique using thin layers of plaster applied with a spatula or trowel and then burnished to create a smooth surface with the illusion of depth and texture. ... Categories: Stub | Construction ...

References

  1. ^ plaster of Paris. The American Heritage® Dictionary of the English Language: Fourth Edition. 2000
  2. ^ BBC NEWS | Education | Amputation after art class burns

External links


  Results from FactBites:
 
Preservation Brief 21: Repairing Historic Flat Plaster--Walls and Ceilings (6294 words)
Plaster was used as the interior surface coating of this elegant 1911 church located in Eugene, Oregon.
Gypsum and lime plasters were used in combination for the base and finish coats during the early part of the 20th century; gypsum was eventually favored because it set more rapidly and, initially, had a harder finish.
A plasterer may have skimped on the amount of cementing material (lime or gypsum) because sand was the cheaper material.
Plaster - Wikipedia, the free encyclopedia (968 words)
Plaster was a common building material for wall surfaces in a process known as lath and plaster, whereby a series of wooden strips are covered with a semi-dry plaster and then hardened into surface.
Plaster moulding is made using a sliding jig that holds a die with a cross section of the moulding.
Cement plaster is a mixture of suitable plaster sand, portland cement and water which is normally applied to masonry interiors and exteriors to achieve a smoothe surface.
  More results at FactBites »

 
 

COMMENTARY     


Share your thoughts, questions and commentary here
Your name
Your comments

Want to know more?
Search encyclopedia, statistics and forums:

 


Press Releases |  Feeds | Contact
The Wikipedia article included on this page is licensed under the GFDL.
Images may be subject to relevant owners' copyright.
All other elements are (c) copyright NationMaster.com 2003-5. All Rights Reserved.
Usage implies agreement with terms, 1022, m