| Popis: |
This paper deals with testing of pre-stressed I-beams, the behaviour of the beams under loading, strengthening methods and their function. In the near history in Finland large commercial buildings have been built using pre-stressed pre-fabricated beams. The cost efficiency has led to designing very slender beams with higher pre-stress forces. This has caused problems in pre-stressed beams around Finland. Damages has been so se-vere that immediate repair of the beams has been necessary in some cases. Tampere University of Technology helped develop and tested these strengthening methods. The results of the tests led to development of a formula that estimates the beam’s extra capacity after post-tensioned strengthening method. |
