Prefabricated cellar
Prefabricated cellar or finished basement there are the walls of a cellar from prefabricated precast concrete elements , which on the construction site only assembled and processed.
history
Until the late 1960s, cellars were mainly made as brick cellars. This means that first a construction pit was dug, then a floor slab was concreted, and then a cellar was built with bricks or sand-lime bricks. This procedure is associated with a relatively high expenditure of time, because proper execution requires craftsmanship and care. From the idea of “healthier” construction, this type of construction can mainly be found in single and multi-family houses. The foundation also consists of concrete. The principles for masonry apply to the dimensioning of the walls. At the beginning of the 1970s, the technical possibilities in the field of prefabrication had matured to such an extent that the prefabricated cellar found its way into the construction industry as a logical addition to the prefabricated house. The production of cellars using semi-finished parts (hollow walls) has also established itself for the construction of apartment buildings, prefabricated ceilings in full assembly construction (especially prestressed concrete hollow boards) are also used extensively in industrial construction. The so-called triple wall was considered a pioneer in the implementation of this idea. This light, so-called hollow wall consisted of a concreted inner and a concreted outer shell. These were connected to each other with reinforcing bars and placed on the floor slab. Only after the cavity walls were erected were the cavities filled with concrete.
Construction
In the manufacture of prefabricated cellars, the walls are made from prefabricated prefabricated elements. In the area of the foundation, i.e. the floor slabs or strip foundations, the monolithic construction method continues to be used. So they are still concreted at the place of use. The production of a reinforced concrete floor slab is considered the rule in family house construction. In a single-family house, it is usually 18 to 20 cm thick. It includes reinforcement of approx. 10 kg of steel per m². The concrete used for the floor slab has a strength class of C 20/25.
The enclosing and supporting walls as well as the reinforcing walls made of prefabricated parts are placed on the foundation (floor slab). The prefabricated elements produced are transported on a low-loader and brought to the construction site. A heavy-duty crane gradually unloads the parts. With support rods that are anchored (screwed) to the base plate and to the wall element, these are then attached to their destination. This can be done largely independent of the weather. With a cellar size of up to approx. 140 m², the time required for this work is approx. 4–5 hours.
One advantage of prefabricated elements is the prefabricated empty piping for sanitary, heating and electrical installations. For this, however, a detailed planning is necessary because an adaptation at the point of use is only possible with great effort. Another advantage is the smooth, ready-to-fill wall surfaces, which simplify the subsequent processing steps compared to masonry walls. A wide range of add-ons such as stairs, light shafts and pipe penetrations can make connections to the walls easier. One result of the mentioned advantages of this type of cellar construction is particularly evident in the area of construction time . This can be considerably shortened compared to a brick cellar. For the buyer of a prefabricated cellar, this results in considerable savings in the area of interim financing for his construction project.
In the next step, the basement stairs are installed as a precast concrete part. Now the ceiling elements can be placed. After completing this work step, the basic structure of the cellar is in place. Now the corresponding reinforcement work is carried out in accordance with the statics specifications and the electrical cables are laid on the basement ceiling. To complete the assembly, in-situ concrete is poured into the cavity walls and in the entire area of the prefabricated ceiling and compacted.
Individual evidence
- ^ Anton Pech: Building Constructions Volume 6 Basement . Springer, 2006, ISBN 3-211-23745-3 , pp. 36 .
- ^ A b Anton Pech: Building Constructions Volume 6 Basement . Springer, 2006, ISBN 3-211-23745-3 , pp. 37 .