Development of a Shotcrete 3D-Printing (SC3DP) Technology for Additive Manufacturing of Reinforced Freeform Concrete Structures

Robotergestützte, magnetische Ausrichtung von Mikro‐Stahldrahtfasern in dünnwandigen UHPFRC‐Bauteilen

“…Über die Anwendung des Verfahrens für in Schalungen gegossene Bauteile aus UHPFRC hinaus ist die Nutzung des Prinzips der magnetischen Faserausrichtung in modifizierter Form auch in der additiven Fertigung von Betonbauteilen möglich. So haben erste Tastversuche zum Einsatz des Verfahrens in einem kombinierten Prozess mit dem im DBFL entwickelten Shotcrete 3D Printing (SC3DP) bereits vielversprechende Ergebnisse zeigen können, die eindeutige Hinweise auf eine mögliche, neuartige Bewehrungsstrategie für schalungslos hergestellte Betonbauteile, wie etwa das in Bild dargestellte Wandelement, geben.…”

The Effect of Accelerator Dosage on Fresh Concrete Properties and on Interlayer Strength in Shotcrete 3D Printing

“…SC3DP is a novel additive manufacturing method using an automated wet-mix shotcrete process [24][25][26]. It is assigned to the open space deposition 3D printing technologies and is especially designed for the manufacturing of large-scale components, Figure 2.…”

Opportunities and challenges for structural engineering of digitally fabricated concrete

“…This process is also referred to as particle bed fusion [28]; however, as it does not involve the melting of a material, the more general term of particle bed 3d printing, previously mentioned should be preferred; and (vi) hybrid techniques which aim to introduce hybrid construction concepts by using the available fabrication processes or reinforcement (e.g. sparse concrete reinforcement in meshworks which combines robot-based 3D concrete printing and textile reinforcement meshes [39] or shotcrete 3D printing which is based on an automated shotcreteing process with the ability to integrate structural reinforcement [40]).  Fabrication site: (i) on-site construction is the production of full houses/structures in an open environment by means of machinery larger (e.g.…”

“…In addition, the additive nature of many DFC techniques yields layered structures with a significant anisotropy with regard to strength (occurring in both the vertical and the horizontal directions) rather than stiffness. The interfaces between adjacent layers generated by additive DFC processes are typically characterised by reduced bond strengths (in both the shear and the normal directions) and are commonly referred to as weak layer interfaces, cold joints or lift lines [40,51]: a number of factors related to the combination of a specific DFC process and material composition (e.g. print head speed, print nozzle height, resting time, and moisture content) have been shown to have quantitative effects on the interface properties, leading, in some cases, to a 50% or higher reduction as compared to the bulk specimens [53].…”