Verbundlos vorgespannte Decken

Prestressed Slabs without Bond. Structural and serviceability: Behaviour after Fire Exposure This article gives some background information about the assessment of the structural behaviour of slabs after fire exposure. The changes in the structural and serviceability behaviour caused by the fire exposure will be shown, together with some design information for the practical use.     

Vorgespannte Bauteile aus textilbewehrtem Beton

Prestressed Textile reinforced Elements The paper shows that prestressing of textile reinforcement results in a higher load bearing capacity and stiffness of a textile reinforced element. Particularities of textile reinforcement for prestressing compared to textile reinforcement for non‐prestressed elements will be described. Special requirements for textiles used for prestressing are explained, which take clamping techniques, bond behaviour and the design of prestressed textile reinforced elements into consideration. In this context, the importance of internal and external bond are discussed.     

Technische Textilien zur Bewehrung von Betonbauteilen

Textile Reinforcement for Concrete For the best transmission of tensile and bending forces in the composite material, the textile reinforcement material has to be inserted as long fibres laid in straight orientation and depending on the load. Through the development of textile manufacturing technologies filament yarns can be manufactured into open grid structures which increase the potential of alternative reinforcements. It is currently possible to manufacture load‐adapted textile structures. It is essential that the high‐performance mechanical properties of the alkali‐resistant glass fibres or carbon fibres used are maintained throughout the manufacturing process until the finished component is complete. Therefore the quality of the yarn orientation and the yarn distribution has to be obtained secured throughout the manufacturing process until the finished textile fabric is complete.     

Vorgespannte Bodenplatten – ein brachliegendes Potential

Prestressed Foundations Slabs Continuous slabs proves to be an attractive foundation system. Foundation slabs can be used to withstand the loading and simultaneously form a tight and continuous element between foundation soil and the building. Foundation slabs are highly stressed structural elements, which require large bending and shear resistance. Thus hugh cross‐sections and large bending and shear reinforcement is needed. A prestressing reinforcement will be ideal to resist especially the high loading. Prestressing is an activ reinforcement element in contrast to the mild reinforcement. The pretensioned part of the steel cause forces, which cause deflection forces due to the curvature of the tendon geometry. Thoses forces will be able to match the individual loading directly and then distribute them continuously over the unloaded slab area. The load bearing system, caused by the deflection loads of the prestressing forces reduces the stresses within the structural element. Consequently slender cross‐section and less amount of mild reinforcement is needed. Additionally the compression stresses due to prestressing forces reduce the cracking and enlarge the tightness of the foundation slab.