Durchstanzmodell für Flachdecken mit Faserverbundbewehrung und großen Aussparungen in Stützennähe

Punching Model for Flat Slabs with FRP Reinforcement and large Openings near the supporting Surface Flat slabs with tension bars using glass‐ or carbon fiber reinforced polymer have a substantial lower punching load capacity then conventional steel reinforced plates. This is caused by the dependence of the shear force transportation on the stiffness and therefore on the elastic modulus of the reinforcement, after concrete is cracked: For glass fiber reinforced polymer the elastic modulus has an amount of approximately 35000 N/mm², which isn't more then one sixth of the steel value. Until now designing rules for concrete don't take into account this influence. Following a new developed punching model will be presented, that compared with DIN 1045 [2] and DIN 1045‐1 [3] directly includes the elastic modulus of the bending reinforcement and that also applicates the reduction of the punching load capacity by openings near the supporting surface in a realistic way.     

Ganzheitliche Analyse von Stahl‐ und Verbundeisenbahnbrücken

Holistic analysis on steel‐ and composite railway bridges – Innovative solutions for strengthening durability and reducing construction times (Part 1). Investigations on sustainability on infrastructure projects differ from comparable investigations on building constructions through their longer life‐cycle of the objects. Questions regarding sustainability are thus accompanied by questions of durability and simple, mostly undisturbed maintenance through the whole life‐cycle. By the application of innovative railway bridges with steel and composite constructions blocking times induced by the construction time and maintenance actions within the usage phase, can be effectively reduced. Additionally the optimization of restrictive fatigue‐details can affect the whole life‐cycle of a bridge‐construction. In the frame of the FOSTA‐AiF‐research project „Holistic Assessment of steel‐ and composite railway bridges according to criteria of sustainability“ different innovative railway bridge types have been compared to their corresponding conventional bridge types and evaluated over their whole life‐cycle to quantify their advantageousness. While this article shows the investigated innovative bridge‐variants in constructive regards and optimization proposals and design approaches are explained, the second article is about the holistic approach and the results of the sustainability assessment of the investigated steel‐and composite railway bridge.