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The detachment of wall paintings involves the removal of a wall painting from the structure of which it formed part. While detachment was once a common practice, the preservation of art in situ is now preferred, and detachment is now largely restricted to cases where the only alternative is total loss. [ 1 ]
Primary efflorescence is named such, as it typically occurs during the initial cure of a cementitious product. It often occurs on masonry construction, particularly brick, as well as some firestop mortars, when water moving through a wall or other structure, or water being driven out as a result of the heat of hydration as cement stone is being formed, brings salts to the surface that are not ...
Calcium Lime Rust, more commonly known as CLR, is a household cleaning product used for dissolving stains, such as calcium, lime, and iron oxide deposits. Ingredients [ edit ]
During the 18th century, new techniques were perfected for the restoration and conservation of ancient works of art, including methods of detaching fresco paintings from walls. Detachment involves separating the layer of paint from its natural backing, generally stone or brick, and can be categorized according to the removal technique used.
Example of secondary efflorescence in parking garage exposed to diluted road salt from vehicles entering the garage during winter. When water flows through cracks present in concrete, water may dissolve various minerals present in the hardened cement paste or in the aggregates, if the solution is unsaturated with respect to them.
Cement hydration and strength development mainly depend on two silicate phases: tricalcium silicate (C 3 S) (), and dicalcium silicate (C 2 S) (). [1] Upon hydration, the main reaction products are calcium silicate hydrates (C-S-H) and calcium hydroxide Ca(OH) 2, written as CH in the cement chemist notation.
Fly ash bricks. Fly ash brick (FAB) is a building material, specifically masonry units, containing class C or class F fly ash and water. Compressed at 28 MPa (272 atm) and cured for 24 hours in a 66 °C steam bath, then toughened with an air entrainment agent, the bricks can last for more than 100 freeze-thaw cycles.
Clinker brick closeup of bricks in the so-called Clinker building on Barrow street in Greenwich Village, New York City. Dutch bricks (clinkers) found at Topsham Museum. Imported between 1660 and 1710, they were used for finer details such as fireplaces. They can be seen in many buildings in Topsham and are sometimes used in boundary walls.