Excellent diploma thesis: Schöck Construction Innovation Award 2022 for Camilla Lewerenz

TUD graduate Camilla Lewerenz has been awarded the Schöck Construction Innovation Prize for her thesis "Investigation of the discontinuity areas of an ortho composite deck".

The Eberhard Schöck Foundation has been honouring up to four outstanding diploma or master's theses in civil engineering with the prize since 2000. The aim is to promote innovative thinking and to realise buildings that are future-oriented, economical and/or durable. The prize is endowed with 2,500 euros.

In her work, for which Camilla Lewerenz also received the Züblin Steel Construction Award in July, she investigated the discontinuity areas resulting from local wheel loads in the longitudinal and transverse directions of the bridge deck. For this purpose, she developed FEM models for a deck and a trough bridge, in particular to investigate the stress on the dowel bars. She designed framework models for the engineering calculation of the load transfer and submitted design proposals for the arrangement of the dowel bars and the formation of the reinforced concrete deck layer.

Summary of the diploma thesis

The strongly increased traffic load and notch severity in the details of orthotropic steel plates lead to considerable fatigue damage of existing steel bridges. With the development of the ortho composite deck (OVP for short) an alternative durable and light composite construction method is created. A thin layer of concrete on top of a longitudinally braced steel plate reduces the susceptibility of the structure to fatigue. The resulting shear forces between the cover sheet and the concrete layer are transferred by dowel bars. However, local stress concentrations due to wheel loads cause discontinuities within the OVP, where increased stresses on the structure are present. These are in the connection area of the longitudinal and transverse beams as well as in the centre of the field.

Within the scope of the diploma thesis, these areas of the ortho composite deck were investigated with composite dowel bars. The main focus was on the load transfer as well as the bond protection within the discontinuity areas of the carriageway slab. The analysis and evaluation was carried out on the basis of finite element models, with which the structure geometry and traffic load were simulated. The framework models developed on the basis of the results create the basis for a simplified design of the discontinuity areas. For areas where increased composite shear forces occur, possible measures to reduce the shear stresses were also presented and investigated. The results of the work form an important basis for the design and dimensioning of the OVP.

Contact:
Prof. Richard Stroetmann,
Chair of Steel Construction