The properties of a concrete wall

The outstanding feature of a concrete wall is its compressive strength. Through unified European standards, the concrete is mixed in solid mixing ratios and with standardized binders. If stability and tensile strength are to be increased, iron reinforcement or fiber admixtures are used.

Long setting time

Concrete walls are created using three different methods. They can be cast on site in a formwork that is built on a foundation or a floor slab. The alternative is to set up prefabricated solid concrete slabs, from which the wall is assembled. In a mixed form already finished concrete part walls can be built into a double wall. The cavity of this concrete wall is then poured with concrete.

An important argument for the use of prefabricated concrete wall parts is the time factor. Depending on the composition and type of concrete, it takes up to 28 days for final setting and drying out. While solid prefabricated concrete walls can be installed in just a few hours and can be loaded to the maximum immediately, double walls and completely cast versions require maintenance.

Compressive strength classes

The compressive strength of a concrete wall is divided into classes whose C abbreviates the English term "concrete" for concrete. In building construction, the strength classes C16 / 20, C20 / 25 and C25 / 30 are usually chosen for a concrete wall. The first number indicates the compressive strength in Newtons per square millimeter. Prefabricated partitions for double walls are made of C20 / 25 concrete.

As usual reinforcements either steel bars or steel mesh mats are used, which are usually only above ground necessary in the normal weight load of an average residential building. As an alternative reinforcing material fibers of plastic, glass or steel can be used.

Concrete components and types

The concrete for a wall is blended from fine sand with a maximum grain size of four millimeters, cement, water and an individual amount of aggregate. The aggregates can be used to influence the physical and chemical properties of the concrete wall. Typical characteristics are aggregates which make the concrete more or less liquid, stabilizing aggregates, means for increasing the production of air pores and additives which accelerate or retard processes in the concrete.

When mixing the concrete for a concrete wall or prefabricated parts, the position and the task of the wall are taken into account. Individually, the concrete wall is made of light, lean, porous or air-porous concrete. Properties such as setting speed and water permeability are regulated by additional additives. Color pigments can be mixed in exposed concrete.

surface treatment

The surface of a concrete wall is usually further processed according to their function and location. Typical is the plastering of the concrete wall both outside and inside. In basement walls, a building drainage accompanying the sealing is often done, for example, by a bitumen paint.

If the concrete wall is to be clad, pressure-resistant concrete mixes are often recommended. A facade of natural stone or metal can develop an enormous weight and develop strong tensile forces. In this case, the reinforcements must be adequately embedded in the concrete wall, so that subsequent anchoring holes can be set easily. Before drilling, the concrete wall must have completely set.

Building regulations and building regulations

If you want to make a concrete wall yourself, do not use an approximate mixture for the construction of supporting walls. Both for concrete walls above a certain height and for load-bearing walls, regionally different building regulations exist. In addition to the standardized and suitable concrete mixtures, the work process must also be carried out professionally, including, for example, proper compaction in the course of casting processes.

In the case of land enclosures, special attention must be paid to neighboring plots of concrete wall. Since a concrete wall leads to a complete shading of the adjacent property areas, the neighbor must be contacted. At best, all concerned parties agree on the position and height of the wall. In the respective national building regulations, the permitted height range between 1.20 and 1.80 meters is stipulated.

Weight of a concrete wall

The weight of a higher concrete wall quickly exceeds half a ton per meter. The substrate, the foundation or a floor slab must be adequately fastened. As a guideline, 2.4 tonnes per cubic meter of concrete wall can be assumed. This corresponds to a wall height of one meter and a thickness of 25 centimeters a weight of 250 kilograms per meter.

The weight of the concrete wall is calculated from the dry bulk density and the densities of the aggregates used. Normal concrete has a density of between two and 2.6 tonnes per cubic meter. Lightweight concrete weighs less than two tonnes and heavy concrete more than 2.6 tonnes per cubic meter. Another factor influencing the density is the type of pores created in the concrete wall. By appropriate surcharges, the five pore types, called gel, shrinkage, capillary, air or compression pores, generated.

Tips & Tricks

If you want to create a concrete wall in your construction project, please inquire in advance about the building regulations. In many cases a concrete observation and constant control is compulsory. Those who do not comply can be forced to dismantle the concrete wall.

Video Board: Understanding Concrete, Cement, and Mortar