In addition to bitumen as a binder, mastic asphalt screed consists of sand, rock flour and chippings. The predominant area of application is in industrial construction and as a parking deck surface, but there are also possible applications in building construction, e.g. for public buildings or residential construction. It is introduced hot (usually at a temperature of 220 – 250 °C) and can be used shortly after cooling. Since it is water-free, it does not bring any additional building moisture into the building. It is also used as a visible surface when sanded, as it is diffusion-tight and moisture-resistant, even in shower areas.
The disadvantages of mastic asphalt screed lie in its low resistance to oils and solvents and in its softer surface compared to other screeds (thermoplastic property), which can yield and get impressions especially under permanently acting point loads when the mastic asphalt is the finished visible surface. For this reason, mastic asphalt screeds must be levelled with a suitable filler before being covered with elastic/textile floor coverings.
Mastic asphalt screed is also suitable for outdoor applications, e.g. on balconies or parking decks.
Thicknesses:
Minimum nominal thickness of floating screed: 25 mm Walk-through
/ higher load: after cooling (approx. 2-3 hours)
A screed is considered ready for subsequent flooring work if it has dried out to such an extent that no major deformations are to be expected as a result of further drying and the nominal flexural tensile strength in accordance with DIN 18560 has been achieved. In the case of mineral-bound screeds, this is checked on the basis of the existing residual moisture of the screed, which is determined by the so-called CM measurement with a calcium carbide measuring device. These types of screed are usually ready for covering after 28 days at the earliest, and depending on various marginal factors, sometimes only much later. [...]
In the case of mastic asphalt screeds , they are ready for paving after they have cooled down completely, i.e. usually as early as 1 day after installation.
Source: bauwion
