Vorspannung ohne Verbund und Flachdecken aus Stahlfaserbeton. Bericht aus der Praxis – Neubau der Realschule Kösching,Landkreis Eichstätt

Prestressing with Unbonded Tendons and Flat Slabs Made of Steel Fibre Concrete. Practical Report – New Secondary School Building at Kösching, Rural District of Eichstätt This work report resumes the subject of the publication of the authors in the journal “Beton‐ und Stahlbetonbau”, no. 4, 2004 and demonstrates the new opportunities in the field of reinforced concrete engineering including the prestressed steel fibre slab as well as estimates in comparison with conventional embodiments under competitive conditions. Meanwhile, various technical journals published articles dealing with “Prestressing with Unbonded Tendons”, which are focussed more on the theoretical bases.This report is to complete these publications by practical experience.     

Einfluß der Faserorientierung auf die Beanspruchbarkeit von Bauteilen aus Stahlfaserbeton

Influence of Fiber Orientation on the Design of Steel Fiber Reinforced Concrete Members The provision of guidelines and codes is the condition to applications with enough margin of safety and spreading of steel fiber reinforced concrete. The knowledge of uneven fiber distribution and orientation didn't lead to consideration within the design until now. One reason may be that a consideration of the fiber distribution was not relevant for the most applications. But there is a change due to the advance of the use of steel fiber reinforced concrete for members and structures based on structural design. The effects of the concreting and the dimensions of a member on the fiber orientation and distribution are considerable and should be taken into account for the design.     

Größere Spannweiten durch Flachdecken aus Konstruktions‐Leichtbeton

Wide spans due to Flat Slabs with Structural lightweight aggregate Concrete Structural lightweight aggregate concrete (SLWAC) shows a much more favourable ration of dead weight to strength than normal weight concrete. The present report indicates the possibilities resulting out of this for the optimisation of flat slabs in view of wider spans. Considering the specific material properties of SLWAC and their consequences on the load bearing system of flat slabs the solution of a hollow body slab is developed in which SLWAC and normal weight concrete are used combined. Those slab systems reach clearly wider spans than conventional nonprestressed normal weight concrete slabs.     

Fundamentplatten aus Stahlbeton und Stahlfaserbeton. Experimentelle Untersuchungen zur Gebrauchstauglichkeit und Tragfähigkeit

Reinforced Concrete and Steel Fibre Reinforced Concrete Rafts Experimental tests on serviceability and ultimate loading performance Houses and residential buildings are increasingly built on rafts instead of strip foundations. The main advantages of rafts are more efficient excavation works and easy concreting of the rafts itself. The use of steel fibre reinforced concrete slabs offers economic advantages if there are no special requirements on service ability such as water tightness or crack limitations. At Aachen University of Applied Sciences a comparative experimental study on the load carrying behaviour of rafts made of concrete, reinforced concrete and steel fibre reinforced concrete was carried out. The tests have proven steel fibre concrete as suitable material for rafts in case of sufficient stiffness of the subbase. In case of special requirements on service ability, reinforced concrete or combined fibre and bar reinforced concrete should be used. In that case stresses should be calculated based on the elastic theory.