durability
In the construction industry, durability in the narrower sense defines the resistance of building materials and components to external influences such as moisture penetration, alternating moisture, heat and cold, temperature changes and frost, solar radiation ( UV light ), chemical attack ( acid rain , de-icing salt , saltpeter ) and pests. and fungal attack in organic materials.
In a broader sense, the resistance of structures to mechanical influences such as static and dynamic loads ( wind loads , earthquakes , vibrations, avalanches , flood waves ) as well as to more unusual events such as lightning strikes or electromagnetic radiation can also be meant.
The period of use, over which the load-bearing capacity and properties of use are to be ensured for components made of reinforced concrete or prestressed concrete, for example , is 50 years, unless otherwise specified and the usual maintenance measures are carried out at the same time.
The components must not change inadmissibly during the entire intended service life, so that they are always sufficiently resistant to all designed impacts and provide the reinforcement with adequate protection against corrosion . To ensure this, sufficient concrete cover for the reinforcing steel or prestressing steel and a suitable concrete composition are required. The associated requirements are regulated in the standards for the respective environmental conditions and stresses present using so-called exposure classes.
In metal construction , the service life depends essentially on the corrosion resistance , statics and heat or cold resistance , in wooden frame construction and the like. a. adequate protection against moisture.
In timber construction , the natural durability of heartwood against biotic degradation is divided into 5 classes according to DIN EN 350-2. Teak is considered to be very durable and belongs to class 1 (1-3), beech is not durable and is classified in class 5. The durability of wood can be increased by chemical wood protection or wood modification .
See also
- Load capacity
- erosion
- natural durability of wood
Individual evidence
- ↑ DIN EN 206-1: 2000 Appendix F.
Web links
- Concrete durability (accessed December 12, 2019)
- Use class, use class, durability class (accessed December 12, 2019)
- Investigation of the natural durability of economically important types of wood under various stresses in outdoor areas (accessed on December 12, 2019)
- Durability, creep coefficient and shrinkage (accessed December 12, 2019)
- Durability of the wood species classes according to DIN EN 350-2 (accessed on December 12, 2019)