Search results
Results from the WOW.Com Content Network
The United States Code defines speleogens as "relief features on the walls, ceiling, and floor of any cave or lava tube which are part of the surrounding bedrock, including anastomoses, scallops, meander niches, petromorphs and rock pendants in solution caves and similar features unique to volcanic caves."
An affected gastropod shell (a juvenile Agathistoma) from a museum collection. Byne's disease, more accurately known as Bynesian decay, is a peculiar and permanently damaging condition resulting from an ongoing chemical reaction which often attacks mollusk shells and other calcareous specimens that are in storage or on display for long periods of time.
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 ...
Excessive water content in the wall will also cause a high risk of efflorescence of salts out of the wall as it dries, thereby damaging plaster and other finishes. Any such salts deposited on the wall surface may contain the fungicide used in the treatment, thereby creating a potential health hazard. [17]
When it reacts with concrete, it causes the slab to expand, lifting, distorting and cracking as well as exerting a pressure onto the surrounding walls which can cause movements significantly weakening the structure. Some infill materials frequently encountered in building fondations and causing sulfate attack are the following: [2] Red Ash
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.
A slurry wall is a civil engineering technique used to build reinforced concrete walls in areas of soft earth close to open water, or with a high groundwater table. [1] This technique is typically used to build diaphragm (water-blocking) walls surrounding tunnels and open cuts, and to lay foundations .
Gypsum waste such as gypsum blocks and plaster do not require the removal of paper, as they are not made with paper from the beginning. It is typical for the gypsum recyclers to accept up to 3 per cent of contamination from other materials. The professional recyclers are capable of handling gypsum waste with nails and screws, wall coverings etc.