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Parging
Repointing is the process of renewing the pointing, which is the external part of mortar joints, in masonry construction. Over time, weathering and decay cause voids in the joints between masonry units, usually in bricks, allowing the undesirable entrance of water. Water entering through these voids can cause significant damage through frost weathering and from salt dissolution and deposition. Repointing is also called pointing,"pointing, vbl. n 1. " def. 5 ''Oxford English Dictionary'' Second Edition on CD-ROM (v. 4.0) © Oxford University Press 2009 or pointing up, although these terms more properly refer to the finishing step in new construction. Tuckpointing is also commonly used as a synonym, though its formal definition is technically different. History Traditionally, mortar was made with lime and sand, producing lime putty. In the early 20th century, masons began using Portland cement, a strong, fast drying cement. Masonry cement made its appearance in the 1930s, which i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Bundesarchiv Bild 183-2005-0721-510, Vorpommern, Bau Von Neusiedlerhäusern
The German Federal Archives or Bundesarchiv (BArch) (, lit. "Federal Archive") are the national archives of Germany. They were established at the current location in Koblenz in 1952. They are subordinated to the Federal Commissioner for Culture and the Media (Claudia Roth since 2021) under the German Chancellery, and before 1998, to the Federal Ministry of the Interior. On 6 December 2008, the Archives donated 100,000 photos to the public, by making them accessible via Wikimedia Commons. History The federal archive for institutions and authorities in Germany, the first precursor to the present-day Federal Archives, was established in Potsdam, Brandenburg in 1919, a later date than in other European countries. This national archive documented German government dating from the founding of the North German Confederation in 1867. It also included material from the older German Confederation and the Imperial Chamber Court. The oldest documents in this collection dated back to the y ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Lime (mineral)
Lime is an inorganic material composed primarily of calcium oxides and hydroxides. It is also the name for calcium oxide which is used as an industrial mineral and is made by heating calcium carbonate in a kiln. Calcium oxide can occur as a product of coal-seam fires and in altered limestone xenoliths in volcanic ejecta. The International Mineralogical Association recognizes lime as a mineral with the chemical formula of CaO. The word ''lime'' originates with its earliest use as building mortar and has the sense of ''sticking or adhering''. These materials are still used in large quantities in the manufacture of steel and as building and engineering materials (including limestone products, cement, concrete, and mortar), as chemical feedstocks, for sugar refining, and other uses. Lime industries and the use of many of the resulting products date from prehistoric times in both the Old World and the New World. Lime is used extensively for wastewater treatment with ferrous ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Tuckpointing
Tuckpointing is a way of using two contrasting colours of mortar in the mortar joints of brickwork, with one colour matching the bricks themselves to give an artificial impression that very fine joints have been made. In some parts of the United States and Canada, some confusion may result as the term is often used interchangeably with '' pointing'' (to correct defects or finish off joints in newly laid masonry) and '' repointing'' (to place wet mortar into cut or raked joints to repair weathered joints in old masonry). History The tuckpointing method was developed in England in the late eighteenth century to imitate brickwork constructed using ''rubbed bricks'' (also ''rubbers'' and ''gauged bricks''), which were bricks of fine, red finish that were made slightly oversized, and after firing, were individually abraded or cut, often by hand, to a precise size. When laid with white lime mortar, a neat finish of red brick contrasting with very fine white joints was obtained. Tuckp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Cannon Renewal Project - June 2017 (35729603482)
A cannon is a large-caliber gun classified as a type of artillery, which usually launches a projectile using explosive chemical propellant. Gunpowder ("black powder") was the primary propellant before the invention of smokeless powder during the late 19th century. Cannons vary in gauge, effective range, mobility, rate of fire, angle of fire and firepower; different forms of cannon combine and balance these attributes in varying degrees, depending on their intended use on the battlefield. A cannon is a type of heavy artillery weapon. The word ''cannon'' is derived from several languages, in which the original definition can usually be translated as ''tube'', ''cane'', or ''reed''. The earliest known depiction of cannons may have appeared in Song dynasty China as early as the 12th century; however, solid archaeological and documentary evidence of cannons do not appear until the 13th century. In 1288, Yuan dynasty troops are recorded to have used hand cannons in combat, and the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Repointing The Front Facade Of A Rowhouse, 117 W
Repointing is the process of renewing the pointing, which is the external part of mortar joints, in masonry construction. Over time, weathering and decay cause voids in the joints between masonry units, usually in bricks, allowing the undesirable entrance of water. Water entering through these voids can cause significant damage through frost weathering and from salt dissolution and Weathering#Salt-crystal growth, deposition. Repointing is also called pointing,"pointing, vbl. n 1. " def. 5 ''Oxford English Dictionary'' Second Edition on CD-ROM (v. 4.0) © Oxford University Press 2009 or pointing up, although these terms more properly refer to the finishing step in new construction. Tuckpointing is also commonly used as a synonym, though its formal definition is technically different. History Traditionally, mortar was made with lime and sand, producing lime putty. In the early 20th century, masons began using Portland cement, a strong, fast drying cement. Masonry cement made its a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Lime Mortar
Lime mortar or torching is a masonry mortar (masonry), mortar composed of lime (material), lime and an construction aggregate, aggregate such as sand, mixed with water. It is one of the oldest known types of mortar, used in ancient Rome and ancient Greece, Greece, when it largely replaced the clay and gypsum mortars common to ancient Egyptian construction. With the introduction of Portland cement during the 19th century, the use of lime mortar in new constructions gradually declined. This was largely due to the ease of use of Portland cement, its quick setting, and high compressive strength. However, the soft and porous properties of lime mortar provide certain advantages when working with softer building materials such as natural stone and terracotta. For this reason, while Portland cement continues to be commonly used in new brick and concrete construction, its use is not recommended in the repair and Building restoration, restoration of brick and stone-built structures origin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Cannon Renewal Project - June 2017 (35511277590)
A cannon is a large-caliber gun classified as a type of artillery, which usually launches a projectile using explosive chemical propellant. Gunpowder ("black powder") was the primary propellant before the invention of smokeless powder during the late 19th century. Cannons vary in gauge, effective range, mobility, rate of fire, angle of fire and firepower; different forms of cannon combine and balance these attributes in varying degrees, depending on their intended use on the battlefield. A cannon is a type of heavy artillery weapon. The word ''cannon'' is derived from several languages, in which the original definition can usually be translated as ''tube'', ''cane'', or ''reed''. The earliest known depiction of cannons may have appeared in Song dynasty China as early as the 12th century; however, solid archaeological and documentary evidence of cannons do not appear until the 13th century. In 1288, Yuan dynasty troops are recorded to have used hand cannons in combat, and the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Atomic Absorption Spectroscopy
Atomic absorption spectroscopy (AAS) is a spectro-analytical procedure for the quantitative measurement of chemical elements. AAS is based on the absorption of light by free metallic ions that have been atomized from a sample. An alternative technique is atomic emission spectroscopy (AES). In analytical chemistry, the technique is used for determining the concentration of a particular element (the analyte) in a sample to be analyzed. AAS can be used to determine over 70 different elements in solution, or directly in solid samples via electrothermal vaporization, and is used in pharmacology, biophysics, archaeology and toxicology research. Atomic emission spectroscopy (AAS) was first used as an analytical technique, and the underlying principles were established in the second half of the 19th century by Robert Wilhelm Bunsen and Gustav Robert Kirchhoff, both professors at the University of Heidelberg, Germany. The modern form of AAS was largely developed during the 1950s by a t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
X-ray Diffraction
X-ray diffraction is a generic term for phenomena associated with changes in the direction of X-ray beams due to interactions with the electrons around atoms. It occurs due to elastic scattering, when there is no change in the energy of the waves. The resulting map of the directions of the X-rays far from the sample is called a diffraction pattern. It is different from X-ray crystallography which exploits X-ray diffraction to determine the arrangement of atoms in materials, and also has other components such as ways to map from experimental diffraction measurements to the positions of atoms. This article provides an overview of X-ray diffraction, starting with the early #History, history of x-rays and the discovery that they have the right spacings to be diffracted by crystals. In many cases these diffraction patterns can be #Introduction to x-ray diffraction theory, Interpreted using a single scattering or kinematical theory with conservation of energy (#Ewald's sphere, wave vecto ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Scanning Electron Microscope
A scanning electron microscope (SEM) is a type of electron microscope that produces images of a sample by scanning the surface with a focused beam of electrons. The electrons interact with atoms in the sample, producing various signals that contain information about the surface topography and composition. The electron beam is scanned in a raster scan pattern, and the position of the beam is combined with the intensity of the detected signal to produce an image. In the most common SEM mode, secondary electrons emitted by atoms excited by the electron beam are detected using a secondary electron detector ( Everhart–Thornley detector). The number of secondary electrons that can be detected, and thus the signal intensity, depends, among other things, on specimen topography. Some SEMs can achieve resolutions better than 1 nanometer. Specimens are observed in high vacuum in a conventional SEM, or in low vacuum or wet conditions in a variable pressure or environmental SEM, an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Thin Section
In optical mineralogy and petrography, a thin section (or petrographic thin section) is a thin slice of a rock or mineral sample, prepared in a laboratory, for use with a polarizing petrographic microscope, electron microscope and electron microprobe. A thin sliver of rock is cut from the sample with a diamond saw and ground optically flat. It is then mounted on a glass slide and then ground smooth using progressively finer abrasive grit until the sample is only 30 μm thick. The method uses the Michel-Lévy interference colour chart to determine thickness, typically using quartz as the thickness gauge because it is one of the most abundant minerals. When placed between two polarizing filters set at right angles to each other, the optical properties of the minerals in the thin section alter the colour and intensity of the light as seen by the viewer. As different minerals have different optical properties, most rock forming minerals can be easily identified. Plagioclase ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Architectural Conservator
Conservation and restoration of immovable cultural property describes the process through which the material, historical, and design integrity of any immovable cultural property are prolonged through carefully planned interventions. The individual engaged in this pursuit is known as an architectural conservator-restorer. Decisions of when and how to engage in an intervention are critical to the ultimate conservation-restoration of cultural heritage. Ultimately, the decision is value based: a combination of artistic, contextual, and informational values is normally considered. In some cases, a decision to not intervene may be the most appropriate choice. Definitions Narrow definition The Conservation Architect must consider factors that deal with issues of prolonging the life and preserving the integrity of architectural character, such as form and style, and/or its constituent materials, such as stone, brick, glass, metal, and wood. In this sense, the term refers to the "profe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
