Deformation of reinforced and prestressed concrete beams with large webopenings

Deformation of reinforced and prestressed concrete beams with large webopenings The success of sustainable building concepts in practice strongly depends on the development of innovative floor slab solutions which feature high flexibility and adaptability and allow for easy changes of utilization. This flexibility is achieved by large spans and adaptive routing of building services. To reduce the construction height and the resource demand, there are efforts to fully integrate the building services into the construction height of the floor slab. This necessitates the arrangement of openings in the filigree structural elements. For slender structural elements under bending loads with large spans the deflection control is decisive for design. Beside time depending effects the influence of large web openings on the deflections has to be taken into account. In this paper, existing models for the determination of the additional deflections due to large web openings in reinforced and prestressed concrete beams are analyzed and a simple approach for prestressed girders which is suitable for hand calculations is developed. A comparison with experimental results confirms the trend-free detection of the significant factors influencing the additional deformations of the developed model.