Bewehrungsoberfläche

Bewehrungsoberfläche refers to the outer surface of reinforcing steel bars, commonly known as rebar, used in concrete construction. This surface is crucial for ensuring the proper bond between the concrete and the steel. The bond is the mechanism that allows the steel to effectively carry tensile stresses, which concrete cannot withstand on its own.

The Bewehrungsoberfläche is typically modified to enhance this bond. For plain, smooth bars, the bond is primarily due to adhesion and friction. However, modern reinforcing bars are almost exclusively ribbed or deformed. These deformations, which can take various forms like lugs, ribs, or indentations, create mechanical interlocks with the surrounding concrete. When the concrete hardens, it flows around these deformations, creating a strong mechanical grip.

The condition of the Bewehrungsoberfläche is important for its performance. Rusting or the presence of excessive mill scale can negatively impact the bond. While a light coating of rust is often considered beneficial as it can improve the surface roughness, heavy rust can lead to a reduction in the bar's cross-sectional area and compromise the bond. Similarly, thick layers of mill scale, a flaky oxide layer formed during the steel's manufacturing process, can detach and weaken the bond. Therefore, proper handling and storage of reinforcing steel are essential to maintain a suitable Bewehrungsoberfläche.