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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 ...
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.
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.
Degrading concrete has been the focus of many studies and the most obvious sign is calcium-rich leachate seeping from a concrete structure. [5] [6] [7]Calthemite stalactites can form on concrete structures and "artificial caves" lined with concrete (e.g. mines and tunnels) significantly faster than those in limestone, marble or dolomite caves.
Slipform stonemasonry is a variation of Cyclopean concrete stone-wall construction that uses formwork to contain the rocks and mortar while keeping the walls straight. Short forms, up to two feet tall, are placed on both sides of the wall to serve as a guide for the stonework.
In most climates it is often better to have a vapor-open building assembly, meaning that walls and roofs should be designed to dry: [6] either to the inside, the outside, or both, so the ventilation of water vapor should be taken into consideration. A vapor barrier on the warm side of the envelope must be combined with a venting path on the ...
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.