Metodik för fastställande av bärförmåga på befintliga betongkonstruktioner

Sammanfattning: Many buildings are now nearing the end of their service life. This applies to both the older houses from the 40's and 50's to the million project houses that did not prove to be as sustainable in the long run. Often there is a desire to extend the service lifetime, but to do that you need to make detailed inspections. The Folkets hus in Gävle is one of those buildings that is in need of renovation and to fulfill the new requirements that must be met in today's buildings. It is desired to make the buildings rentable space more attractive and to extend the building with two more floors. This thesis aims to develop a methodology for determining the condition of load-bearing concrete structure and to test this methodology on an older existing building. The selected building is a community hall in Gävle, built in the late 1940s. It is a heavy structure building of five floors with columns and beam system. A preliminary investigation has been carried out to find information about construction, and through the study of construction documents. With the construction drawings we could determine the building's basic design, concrete class, fixation of walls in the building where the beam load coming down the foundation wall. There was also an assessment of the drawing's resemblance to reality. In addition, the building has undergone visual inspections and other information sources have been investigated. Requested reports written in the field of practice / performance / approach for determining a building's status has been read. The test methods available to determine the concrete quality was studied. There are two test methods you can use where one is destructive and the other one is non-destructive. Both test methods were utilized and tested. For the non-destructive test method the Schmidt hammer was used. The non-destructive test method is not valid according to Swedish building regulations BBK (Handbook on concrete). The results with the Schmidt-hammer values can only be complementary to the valid destructive test method performance. For the destructive method we used the drilling of cores. The cores were pressure tested to determine the strength of the concrete.The method it’s produced with the help of knowledgeable in the field, reviewing the published scientific articles and nonfi literature. It is also performed to follow Swedish standards, Eurocodes and BBK. This means that the results can be compare to similar results in Scandinavia and Europe. The developed methodology has generated a result that is reliable and can be controlled. That gives a credible methodology that allows it to be used for similar projects.