Band 3, Heft 6

A probabilistic method to evaluate the reliability of structural masonry elements is presented. Local probability of failure, different failure modes and corresponding limit state functions, probability distributions of basic variables and model uncertainty are discussed. A graphical probability mapping is presented as an easilyaccessible, visual evaluation instrument in the restoration decision process. The proposed methodology is illustrated on tested shear panels, reported in literature.

Testing of coating systems for the surface protection of directly trafficable concrete areas is based on different national guidelines, e.g. ZTV-SIB and the guidelines for the protection and the repair of concrete structures (Rili-SIB of DAfStb) with the systems of class OS-F and OS 11 resp. One of the basic parameters to judge the durability is the testing of the crack bridging capacity in case of temperature and load dependent movements. In addition to the „mortar prism method", originally worked out by BAM and being referred to in the guidelines, different test methods, such as the „concrete slab method", are alternatively used in practice. This investigation aimed at the comparison of the different substrate sand testing principles. The tests revealed comparable results between crackbridging tests of coatings on cement mortar prisms and concrete slabs for the chosen testing parameters. The results will be taken into consideration in the elaboration of the European standardization for surface protection systems.

In this state of the art report the electrochemical, non destructive techniques for the survey, assessment and the quality control of reinforced concrete structures such as the potential mapping, the measuring of concrete resistivity and the polarisation resistance for on-site applications are described. Along with a short description of each technique especially those aspects are discussed, that are important for on-site applications: possibilities and limits of the technique as well its suitability for use in the different stages of rehabilitation works. The examples from practical on-site applications will be presented in a following report.

Keywords In the context of sound propagation in buildings, we must differentiate between building parts which produce noise actively (water conducting parts, facilities with electrical motors and other equipment) and building parts which do not cause any noise but have a sound protecting function, such as e.g. ceilings or walls. We recognise that certain building parts do not change their sound protection function for long decades, while other parts are getting sound proof leaky due to amortisation (e.g. carpets, water spouts, window gaskets) or due to slow deformation in buildings (plaster dwellings, window and door surrounds). Moreover, various building parts are insufficiently dimensioned concerning their noise protection or have been carried out in a wrong way. This inevitably leads to an overhaul as mentioned above.

Structural design and the position of the sustaining wall Entschigtal were at the origin of corrosion of the back layer of reinforcement. A drecrease of the load bearing section was observed in 1995. The assessment of the actual state of the reinforcement turned out to be a complex task in the context of the inspection of the structure. It was the combination of different test methods which finally led to reliable results concerning the extent and the position of corrosion of reinforcement. In order to restore the load bearing capacity for the remaining required service- life consolidation measures werde necessary. Permanent strand anchors have been placed to strengthen the wall.