Effects of sustained loads on structural response of reinforced concrete constructions

Concrete constructions are often subjected to sustained loads during their service life. In this project of Graduate College 2075 “Modelling the constitutive evolution of building materials and structures with respect to aging”, the material behaviour of different types of concrete is to be examined under sustained loads.

Read more …

Compact Extra High Voltage Poles and Cross Arms (KoHöMaT)

The objective of the project is to develop an environmentally and resource friendly construction of Extra High Voltage Poles, that contributes with a compact arrangement of the conductors to a significant reduction in line width and required area – maintaining the technical safety. Another objective is that the construction should match economic requirements of steel lattice masts but with low life-cycle costs.

Read more …

Background research and comparative calculations to the Eurocode 2 in context of the analysis of the national annexes – Background research to the factors αcc and αct

With introduction of the Eurocode 2 (EC2) national annexes were formulated for each CEN-member state, in order to allow the application of the rules in the member states. In the national annexes of the countries some factors with different values were specified, including the factors αcc, αct and kt. In context of a revision and adaption of these factors, the experimental data used for determination of the factors are gathered and evaluated.

Read more …

Initiative PRB - Regulation for limiting the crack width

For preparation of the design phase of a new generation of Eurocodes, the backgrounds of current existing concepts have to be analysed and compared for the proof of limiting the crack width (DIN 1045, EC 2, MC 2010). 

Read more …

Fatigue strength of built-in prestressing steels under dynamic loads

Within two DIBt research projects, the fatigue behaviour of prestressing steel in pre- and post-tensioned concrete beams was investigated experimentally and theoretically.

Read more …

Further Development of Rules for Design and Detailing of Large Diameter Bars (> Ø32 mm, B500) - Structural Behavior of Compression Members

The use of reinforcing bars with large diameters up to Ø40 mm can be advantageous for several reasons. For instance, highly stressed and heavily reinforced structures, such as columns, achieve significant simplifications in the configuration of the reinforcement. The application of larger bar diameter decreases the number of reinforcement bars, and thus the amount of work during installation. Due to the larger spacing between the bars, concreting and compaction can be simplified. Furthermore, bundled bars and complex lapping of bars can be avoided.

Read more …

Priority Program 1542 “Concrete Light” (1st funding period) – Ultra-light, thin-walled hollow concrete members

The research project deals with fundamental investigations regarding the load-bearing behaviour of Ultra-light, thin-walled hollow concrete members. These concrete members can be applied as single elements (e.g. columns in high-rise buildings), as parts of a larger element (e.g. as a segment of a tower or mast) or as a part of a two-dimensional or spatial truss structure.

Read more …

Compensatory Surveillance of Existing Concrete Buildings

Increasing traffic on German motorways and resulting damage processes as well as ageing processes of the building materials and new design standards produce high demands in reviews of structural calculations. These reviews are based on the “Nachrechnungsrichtlinie” published by the Federal Ministry of Traffic. 

Read more …

Priority Program 1182 – Monolithic Box Girders and Prestressed Segmental Components made of UHPC under Torsion and Combined Bending, Shear and Torsion

Within the third funding period of the Priority Program SPP 1182 "Sustainable Building with Ultra-High Performance Concrete (UHPC)" of the German Research Foundation (DFG), the load-deformation behavior of thin-walled monolithic and segmental box girders, which are made from ultra-high performance fibre-reinforced concrete (UHPFRC) and loaded under pure torsion and combined loading of prestressing, bending, shear and torsion, was to be examined experimentally, numerically and theoretically.

Read more …

Priority Program 1182 – Thin-Walled Circular Hollow Buildings Members made of Ultra-High Strength Concrete

During the third funding period of the Priority Program "Sustainable Building with Ultra-High Performance Concrete" (SPP 1182) of the German Research Foundation (DFG), the load-deformation behavior of thin-walled circular hollow building members made of ultra-high performance concrete (UHPC) was tested.

Read more …

Development of columns with high-strength reinforcement

Within a ZIM project (Zentrales Innovationsprogramm Mittelstand) funded by the BMWi (Federal Ministry for Economic Affairs and Energy), experimental and theoretical investigations were carried out to the load-deformation behaviour of spun-concrete columns made of high-strength reinforcing steel and ultra-high performance concrete. Furthermore, the short and long term material behaviour of the high-performance materials was examined.

Read more …

Adaptive "Tube-in-Tube" Bridges

Adaptive means adaptable or versatile. An adaptive bridge has to be able to adapt to increased loads as well as an adjustment of its amount of traffic lanes, its equipment or any type of restructuring. A later adaptation can already be considered during the design process to ensure a fast and simple addition of reinforcing elements without intensive workmanship and bridge closures.

Read more …

NTH-Top-Down-project network: „Strategies and Methods of Life-Cycle-Engineering for Engineering Works and Buildings“

Life-Cycle-Management or Life-Cycle-Engineering (LCE) contains all measures securing the functionality of buildings throughout their complete service life. This is one of the great challenges for the future of the building industry since resources are scarce and a long-term use of infrastructure projects is highly demanded. Furthermore criteria like technical security, economic efficiency, sustainability or ecology have to be met.

Read more …

Cracking behaviour of skew reinforced concrete members

The formation of cracks is a characteristic phenomenon of reinforced concrete. Excessive crack widths can lead to corrosion of the reinforcing steel, a decrease of durability, leakage or an unacceptable appearance of reinforced concrete structures. A basic understanding of the cracking process, the mechanical behaviour of cracked concrete members and the appropriate calculation of crack widths are necessary to ensure a safe and sustainable design of reinforced concrete structures.

Read more …

Development of innovative hybrid prestressed concrete beams with perforated sheet reinforcement for the precast construction

The aim of this research project was the development of innovative prestressed concrete girders having a high flexibility and functionality in the use of large openings for technical installations (pipes, lines). The girders should be optimized with regard to the material requirements and workload. Furthermore they should have the potential to stand in direct competition with cellular beams in steel or steel composite constructions.

Read more …

Priority Program 1182 –Load-Deformation Behaviour of Compression Members made of Ultra-High Performance Fibre Reinforced Concrete (UHPFRC) with High-Strength Longitudinal Reinforcement

Within the Priority Program SPP 1182 "Sustainable Building with Ultra-High Performance Concrete (UHPC)" of the German Research Foundation (DFG), experimental and theoretical investigations on the load-deformation and post-fracture behavior of columns made from ultra-high performance fibre reinforced concrete (UHPFRC) with high-strength longitudinal reinforcement was examined.

Read more …