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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.
A common example is polyethylene sheeting laid under a concrete slab to prevent the concrete from gaining moisture through capillary action. [5] A DPM may be used for the DPC. Integral damp proofing in concrete involves adding materials to the concrete mix to make the concrete itself impermeable.
In many cases, damp is caused by "bridging" of a damp-proof course that is otherwise working effectively. For example, a flower bed next to an affected wall might result in soil being piled up against the wall above the level of the DPC. In this example, moisture from the ground would be able to ingress through the wall from the soil.
Uncovered concrete dries from the top down. Concrete moisture meters measure only the top inch at most [5] and this area is drier than the concrete further down. Once a floor covering has been installed the moisture in the slab equilibrates. In order to ensure the equilibrated moisture will be a safe level [6] for a floor covering, a relative ...
An MVTR result without specifying these conditions is almost meaningless. Certainly no two results should be compared unless the conditions are known. For example, the effect of temperature on the permeability can be as high as 10% per °C, making it possible that MVTR results achieved at 23°C and 37°C can differ by a factor 4.
In civil engineering, concrete leveling is a procedure that attempts to correct an uneven concrete surface by altering the foundation that the surface sits upon. It is a cheaper alternative to having replacement concrete poured and is commonly performed at small businesses and private homes as well as at factories, warehouses, airports and on roads, highways and other infrastructure.
For example, pharmaceuticals that pick up more than 5% by mass, between 40 and 90% relative humidity at 25 °C, are described as hygroscopic, while materials that pick up less than 1%, under the same conditions are regarded as non-hygroscopic. [32] The amount of moisture held by hygroscopic materials is usually proportional to the relative ...
Concrete has a very low coefficient of thermal expansion, and as it matures concrete shrinks. All concrete structures will crack to some extent, due to shrinkage and tension. Concrete which is subjected to long-duration forces is prone to creep. The density of concrete varies, but is around 2,400 kilograms per cubic metre (150 lb/cu ft). [1]