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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 ...
GGBS cement also produces a smoother, more defect-free surface, due to the fineness of the GGBS particles. Dirt does not adhere to GGBS concrete as easily as concrete made with Portland cement, reducing maintenance costs. GGBS cement prevents the occurrence of efflorescence, the staining of concrete surfaces by calcium carbonate deposits.
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
Concrete carbonation can be visually revealed by applying a phenolphthalein solution over the fresh surface of a concrete samples (concrete core, prism, freshly fractured bar). Phenolphthalein is a pH indicator , whose color turns from colorless at pH < 8.5 to pink-fuchsia at pH > 9.5.
Epoxy moisture control systems can be applied over concrete with relative humidity levels up to 100%, and there are systems available on the market today that can be applied over concrete that is physically damp. In some cases, with the use of an epoxy moisture control system, floor coverings can be installed just 7 days after the slab is poured.
Efflorescence is usually the result of mineral solutions in the capillary channels being drawn to the surface. If the water evaporates, the minerals remain as the so-called efflorescence. It also can be the result of chemical reaction; if badly prepared cement-based mortar is applied to maintain the stone in position, free calcium hydroxide may ...
An early project used a concrete comprising a 50% Portland cement substitution using a silica sand EMC. This was deployed for the construction of a road bridge in Karungi, Sweden, in 1999, with Swedish construction firm Skanska. The Karungi road bridge has withstood Karungi's harsh subarctic climate and divergent annual and diurnal temperature ...
Originally, and in later poorly constructed walls, the rubble was not consolidated. Later, mortar and cement were used to consolidate the core rubble and produce sturdier construction. Modern masonry still uses core and veneer walls; however, the core is now generally concrete block instead of rubble, and moisture barriers are included. [2]