Loading...

fib Bulletin 92 Serviceability Limit State of Concrete Structures – Prof Jan Vítek

412 views

Loading...

Loading...

Transcript

The interactive transcript could not be loaded.

Loading...

Rating is available when the video has been rented.
This feature is not available right now. Please try again later.
Published on Dec 2, 2019

fib Bulletin No. 92. Serviceability Limit State of Concrete Structures is available for purchase: https://www.fib-international.org/pub...

fib Model Code 2010 was published finally in 2013. The somewhat limited space in that document resulted in the publication of this Bulletin which should serve as a supplementary source of knowledge in the field of serviceability limit states (SLS). The design philosophy of limit states requires the check of two kinds of limit states. The ultimate limit states guarantee the safety of structures. The serviceability limit states guarantee the proper function, durability and favourable appearance of concrete structures. If the serviceability limit states are not satisfied, the user will complain that the structure was not built correctly, since it will suffer from cracking, deformations or vibrations. If the criteria of ultimate limit states are not satisfied, in many cases, the user will not realise that the safety of his structure is not as good as he expected. Although there is no intention to denigrate the importance of ultimate limit states, the serviceability limit states have great importance for the correct design of durable concrete structures.
In the last decades, there is great pressure for cost savings in load-carrying concrete structures. Although the costs of a concrete structure of a typical building are about 20 to 25% of the total costs, there is a permanent pressure to save the cost of the steel and concrete resulting in the minimisation of dimensions. The safety of structures can usually be kept within the code requirements, but the serviceability criteria are quite often violated, which may result in an incorrect function of structures in the future. The correct check of SLS criteria is rather sensitive if structures become more and more slender due to the reasons mentioned above.
This Bulletin provides explanation and extensive knowledge of the MC2010 sect. 7.6. The methods included in the following text should highlight the importance of SLS criteria and show in detail, how the brief information from MC2010 should be used. The detailed explanation of individual partial problems is supplemented by examples. Finally, additional information is provided above the scope of MC2010.
The members of fib TG2.1 "Serviceability limit states", who put this document together, had long discussions on individual parts of this Bulletin. Now the final version is available, but it does not mean that all problems are solved. As an example, the shear effects on deflections, particularly in prestressed structures, are not solved completely. The economic design of watertight structures requires more precise criteria. The application of new materials such as fibre reinforced concrete and ultra-high performance concrete (UHPC) will require further adjustments in SLS criteria. The concrete cover layer of structures made of UHPC, to name one example, certainly need not follow the criteria of Eurocodes and of MC2010. Further research in cooperation with other groups within the fib, will define new values. It will be covered by the work of working groups of fib in the future.
Members of the TG2.1 believe that this Bulletin will contribute to improved design of concrete structures, in terms of SLS criteria, and that it will contribute to a better understanding of design approaches and methods included in MC2010.


Recording & Postproduction: Marie Reymond (fib Secretariat)

Loading...


to add this to Watch Later

Add to

Loading playlists...