Mindestrestvorspannung

Mindestrestvorspannung refers to the minimum residual prestress required in a structural element, typically concrete, to ensure its long-term performance and integrity. This minimum level of prestress is established to counteract various detrimental effects that can arise over the service life of a structure.

One of the primary purposes of mindestrestvorspannung is to prevent or limit cracking under service loads. Concrete is strong in compression but weak in tension. Prestressing introduces compressive forces into the concrete, which offset the tensile stresses that would otherwise develop due to external loads. The mindestrestvorspannung ensures that even under the most unfavorable service load conditions, the concrete remains in a state of compression, thereby avoiding tensile cracking.

Furthermore, mindestrestvorspannung contributes to the durability of the structure. By keeping the concrete in compression, it reduces the ingress of aggressive substances like water, chlorides, and sulfates into the concrete. This protection is crucial in preventing corrosion of the reinforcing steel and degradation of the concrete itself, thus extending the structure's service life.

The specific value of mindestrestvorspannung is determined by relevant design codes and standards, which take into account factors such as the type of structure, the materials used, the environmental conditions, and the expected service loads. These codes provide guidelines and requirements to ensure that structural elements maintain their intended performance throughout their lifespan.