ABSTRACT
Most codes are meant for the design of new buildings and are not developed for application to existing buildings. In practice, however, they are also used for the verification of structural components in the case of building renovation work. In the case of presumed resistance problems, an easy way to deal with this is adding external reinforcement. This is due to the limited loss in height. But this becomes a costly operation when extra fire protection has to be added. A review is made of the different failure mechanisms which leads to alternative bearing paths that can be imagined, avoiding these classic reinforcement techniques. Out of those, a way of thinking is proposed with an extra topping, designed by a simple analytical method, which is already stated in the EN 1992-1-2 (annex E). By doing so, we are fulfilling all static equilibriums, are capable of increasing the fire resistance and improving the acoustic performance + thermal inertia of such a slab. Verifications are done by an FEM analysis of a case-study with the use of an explicit transient creep material model for the concrete to avoid numerical problems. Furthermore, the simplicity and possibilities of the proposed method are shown.
