The assessment of existing structures often requires the application of refined methods that are beyond the scope of design codes for new structures. Over the last 20 years, methodologies inherent to existing structures have evolved in many countries and applied on a national level.
New European technical rules will be developed to cover the assessment, re-use and retrofitting of existing structures, in keeping with the principles and fundamental requirements of the EN Eurocodes. These rules will bring together the different national approaches to a broadly accepted, coherent and harmonised set of rules for existing structures complementing those for the design of new structures.
The new European technical rules for existing structures are intended to cover all types of buildings, bridges and construction works, including geotechnical aspects, exposed to all kind of actions. They complement rules of the relevant EN Eurocodes by identifying and distinguishing the differences between the design of new structures and the assessment and retrofitting of existing structures.
The generic rules complementary to EN 1990 will address the requirements, structural analysis and verifications, examination, interventions, etc. Rules for actions will cover the remaining service life for which the structure has to fulfil the requirements for structural safety and serviceability. The main issue of material-oriented complementary rules concerns the methodologies for interventions, including retrofitting and strengthening of existing structures.
CEN Technical Specifications on general rules, actions and concrete structures will be developed first. After a period of trial use and commenting, CEN/TC250 will decide whether the CEN Technical Specifications should be converted into Eurocode Parts.
In the frame of CEN/TC250/WG2 activities, a JRC Science and Policy report has been worked out to present:
- the policy framework and the CEN/TC250 initiative;
- existing national regulations and standards in Europe;
- a prospect for CEN guidance.
The report presents scientific and technical background intended to stimulate debate and serves as a basis for further work to achieve a harmonised European view on the assessment and retrofitting of existing structures.
The consideration of sustainability aspects in the construction sector jointly with considerable economic interests have been the main impulse to include the work item of assessment and retrofitting of existing structures in the Mandate M/515 with a high priority. The new European technical rules will be developed using the existing organization of CEN/TC250. The present report has been worked out in the frame of CEN/TC250/WG2 activities. The report contains three parts:
Having in mind the stepwise procedure for preparation of CEN Technical Documents, the contents of Part III is broader, covers more aspects, and includes more information than the normative technical recommendations. In particular, key issues are identified that require resolution and a summary of different national perspectives is provided rather than seeking to resolve all difficult technical issues during the first work step. The report presents scientific and technical background intended to stimulate debate and serves as a basis for further work to achieve a harmonized European view on the assessment and retrofitting of existing structures.