Hard concrete coverings are laid ready for use in combination with a substructure. They offer a flat surface with a high resistance to mechanical stress and are undemanding to maintain. They are mainly used in industrial and commercial enterprises, namely in those areas that are exposed to heavy wear and tear as a result of goods handling. They are therefore one of the coverings for industrial floors. However, they are not produced by industry itself, but carried out by the construction industry. Success still requires great craftsmanship. A concrete ceiling or floor slab serves as a substructure. Otherwise, the hard concrete will not be able to meet the requirements set. Thanks to the combination with this construction, an additional
joint division is not necessary. Hard concrete is therefore also classified as jointless floor coverings, as they have been standardised in Switzerland since 1988.
Hard concrete flooring is made with normal Portland cement. They differ from an ordinary cement coating in that they can be subjected to higher loads. Their aggregate consists partly or entirely of hard materials. Depending on your needs, you can add additives. In Germany and Austria, they are referred to as "cement-bound hard material screeds". Because of the necessary knowledge of mixing and execution, they are often offered by specialized companies that have introduced their own brand names for their types.
As with any floor covering, planning is the task of the architect. The structure of the floor is simple, because usually only the mechanical stress is decisive. If heat and sound insulation are to be taken into account, these problems must be solved in a higher-level context. The hard concrete/substructure system does not exhibit any particular resistance for these purposes. As a cement-bound surface, however, hard concrete is vapour-permeable and resistant to moisture. It can tolerate smaller amounts of oil, grease and solvents, but not acids, which can be contained even in harmless liquids. Exposure to frozen de-icing salt would also be disadvantageous and would result in an elaborate recipe. Therefore, the future use must be carefully clarified. Hard concrete can be coloured on request. This is done by adding colour pigments according to the rules of concrete technology.
An engineer is usually commissioned with the substructure. This is a matter of course for load-bearing parts such as ceilings and foundation slabs of buildings
. In the case of floors that lie directly on the ground and are not part of the building construction, such as in large halls, a floating floor slab is still required due to the static load. It is to be regarded as an independent, load-bearing part and must
be constructed accordingly. Hard concrete flooring is designed for floors that are located inside buildings. For outdoor usable areas, a structure according to the rules of road construction is recommended because of its resistance to frost and de-icing salt.
