Usability (construction)
In construction , the term serviceability (also serviceability ) describes the property of a building to guarantee unrestricted use for the intended purpose. Together with the properties of safety, reliability and availability, it forms the fundamental pillars of structural engineering. The requirement criteria are defined in regulations introduced by the building authorities, such as standards and special approvals. These regulations are constantly being adapted to the state of the art and changing requirements.
features
In the design of components and structures of buildings by means of static calculation first the demand has the respect carrying capacity are met. In addition, the usability must be proven.
With regard to usability, the relevant standard DIN 1055-100 states:
"A building must be designed and built in such a way that, during the intended service life, it retains its load-bearing capacity as well as its serviceability and durability with appropriate maintenance expenditure"
The verification is necessary because the limit states of the load-bearing capacity and the serviceability are not proportional. This means that a ceiling beam, for example, has a sufficient load-bearing capacity, but the requirements with regard to maximum deflection are not met. The requirements for the component are therefore usually higher than would be necessary for the proof of the load-bearing capacity alone.
Typical requirements for usability are crack width restrictions, water tightness and deformation or vibration limitation.
conditions
The following requirements apply to the usability of a structure:
- perfect functioning of the entire structure
- Well-being of the people who are part of the planned use of the building
- Appearance in optically perfect condition
If one or more of these points are not fulfilled, the usability is not or no longer given.
Limit states of serviceability
The limit state of usability (short: GZG or SLS for serviceability limit state ) is reached when the above requirements can no longer be met. This limit state is reached due to the following reasons:
- Loss of static equilibrium
- excessive deformation
- Material fatigue
- sudden material failure
See also
Norms and standards
- DIN 1055-100 - Fundamentals of structural engineering - Safety concept and design rules
- DIN EN 1990 - Basics of structural planning (12-2010) in connection with DIN EN 1990 / NA - National Annex (12-2010)
Individual evidence
- ^ Konrad Zilch: Handbook for civil engineers . Springer Verlag, 2002, ISBN 3-540-65760-6 , chapter 1 - page 217.
- ↑ Otto W. Wetzell: Wendehorst Bautechnische number tables . Teubner-Verlag, 2002, ISBN 3-519-45002-X , page 244.