Zur Ortbeton‐Ergänzung einschaliger Halbfertigteilwände.

On the completion of single‐panel semi‐precast walls with in‐situ concrete The Institute for structural engineering of TU Wien is currently developing a new construction method for prestressed box girder bridges, using thin‐walled semi‐precast elements that considerably reduce the weight during construction. The smallest selfweight during construction is achieved when using single‐panel walls in the web of the box girder. This paper deals with investigations on the addition of in‐situ concrete to such single‐panel semi‐precast walls, presenting three proposed solutions, with shotcrete, conventional formwork and a solution that corresponds to a double wall in its effect. These were tested in practice, the concrete quality was examined on drill cores and the concrete strength of the shotcrete was tested with the help of destructive tests. The investigations showed that large built‐in components such as ducts and steel girder flanges favour the formation of spray shadows with shotcrete and that conventional formwork next to a semi‐precast wall is practicable but costly in execution. Measurements showed the rapid reduction of the fresh concrete pressure when filling a wall with formwork on one side. By connecting two panels, a double wall is always to be preferred both from a static and a practical construction point of view. Where this is not possible, conventional formwork or prefabricated elements should be fixed to the semi‐prefabricated wall to achieve the same static effect as with a double wall. [ABSTRACT FROM AUTHOR]