Structural engineering deals with the design and construction of engineering structures.
The majority of the existing reinforced concrete structures were designed without regard to the effects of earthquakes. However, the aftermath of several severe earthquakes showed that the seismic behavior of existing and recently erected reinforced concrete structures is often problematic, especially in the frame nodes.
In the context of the research project "SKRIBT"(Protection of critical bridges and tunnels as part of roads) these outer frame nodes are being investigated experimentally as well as analytically under cyclic loads also with regard to existing codes such as the Eurocode and the Indian Standard. The objective is to develop methods to reinforce and repair of existing structures as well as to create design concepts for ductile nodes in new structures using fibre concrete.
The research results will be worked out in recommendations for the implementation of measures for the different target groups: owner, operator and user of road infrastructures as well as rescue services. Finally, some of the determined effective protection measures will be demonstrated at selected bridges and tunnels.
Traditional concrete structures tend to be bulky and massive using a tremendous amount of energy and resources. This is due to the concrete's main ingredients such as gravel, sand and cement . The annual cement production alone consumes approximately 70 Gigajoule (GJ). However, the concrete's strength is rather limited thus requiring large cross-section to absorb the stresses despite steel reinforcement s. Therefore the concrete's dead weight alone limits the spans possible for bridges and girders, not the live load.
The development of ultra-high performance concrete offers a variety of new possibilities. It is 10 times stronger than regular concrete and provided with steel fibers plus accepting the disadvantage of very low tensile strength, regular reinforcement is no longer necessary. Therefore UHPC-structures are much lighter, more filigree and aesthetical than regular concrete structures. In addition UHPC is extremely corrosion-resistant. Using UHPC-components saves approximately 60 % of the resources and about 40 % of the energy and the CO2-emission.
The objective of this research project is the development of basic principles for applying the excellent material characteristics of ultra-high performance fibre reinforced concrete such as extreme high strength and durability in the design of structurally optimized towers for offshore windparks with special emphasis on the great dynamic requirements.
Influence of scale on UHPFRC-elements under combined stress
The effects of climate change on existing prestressed concrete bridges
This research project focuses on the use of strut-and-tie models when designing with structural concrete (reinforced and prestressed concrete). Another aspect are the theoretical approach and examples of the design of discontinuity regions. Examples are areas of load transmission or trusses and raised supports prefabricated elements. The shear strength of structural concrete elements with and without reinforcement is also examined. The results are to be gathered in an extensive database.