Digital Fabrication with Cement-Based Materials: Process Classification and Case Studies

Buswell, Richard A.; Bos, Freek; Silva, Wilson Ricardo Leal da; Hack, Norman; Kloft, Harald; Lowke, Dirk; Freund, Niklas; Fromm, Asko; Dini, Enrico; Wangler, Timothy; Lloret-Fritschi, Ena; Schipper, H.R.; Mechtcherine, Viktor; Perrot, Arnaud; Vasilic, Ksenija; Roussel, Nicolas

doi:10.1007/978-3-030-90535-4_2

Cited by 14 publications

(10 citation statements)

References 49 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In order to address major challenges in construction, such as a low level of automation, a shortage of skilled labour, or high carbon emissions, research and industrial developments are focusing on automation approaches. Especially Additive Manufacturing in Construction (AMC) opens up possibilities for innovative design methods and building strategies for architects and civil engineers [1][2][3]. Hence, different additive manufacturing techniques are investigated, such as particle bed binding [4], material extrusion [5], or material jetting [6].…”

Section: Introductionmentioning

confidence: 99%

The Effects of Nozzle Diameter and Length on the Resulting Strand Properties for Shotcrete 3D Printing

David

Freund

Dröder

et al. 2023

Preprint

View full text Add to dashboard Cite

Additive Manufacturing in Construction (AMC) enables new design methods and strategies within the construction industry. In particular, Shotcrete 3D Printing (SC3DP) offers a high degree of design freedom by enabling the deposition of concrete at variable layer orientation based on a wet-mix shotcrete process. However, the mechanical properties and geometry of the printed layers are dependent on the material and process parameters used. In this context, the effects of air and concrete flow rates, path planning parameters, and material parameters have been investigated in previous research. The here presented study investigates the influence of the nozzle geometry on the resulting strand properties, e.g. strand geometry, layer bond strength, and compressive strength, to evaluate nozzle diameter and length as control parameters for the SC3DP process. Experimental investigations were performed with fixed nozzle diameters between 10 and 30 mm and nozzle lengths ranging from 100 to 200 mm. The results show a significant influence of the nozzle diameter on the resulting strand geometry as well as the mechanical properties. Finally, concepts for a nozzle with a controllable outlet diameter were developed and evaluated.

show abstract

Section: Introductionmentioning

confidence: 99%

The Effects of Nozzle Diameter and Length on the Resulting Strand Properties for Shotcrete 3D Printing

David

Freund

Dröder

et al. 2023

Preprint

View full text Add to dashboard Cite

show abstract

“…Following the rise of additive manufacturing (AM) in many industrial sectors, such as aerospace, mobility and automotive, enabling rapid prototyping and the production of spare and end-use parts [1], AM is now expanding its application towards the construction industry [2]. Besides increasing the building flexibility for form and topology optimised construction elements [3,4], an increased process and building efficiency are achieved by reducing manual labour through automation [5].…”

Section: Introductionmentioning

confidence: 99%

Shotcrete 3D Printing ‐ Interaction of nozzle geometry, homogeneity and hardened concrete properties

Freund,

David,

Böhler

et al. 2023

ce papers

Self Cite

View full text Add to dashboard Cite

Shotcrete 3D Printing (SC3DP) applies concrete layer by layer using a wet‐spray process. The resulting hardened concrete properties of the applied SC3DP layers (e.g. height, width or mechanical strength) are largely dependent on the selected material and process parameters. In this context, the nozzle geometry is an important influencing parameter. During printing, the velocity of the shotcrete jet is significantly influenced by the nozzle outlet diameter. Therefore, in the present study, the effect of the nozzle outlet diameter (15 ‐ 30 mm) is investigated with regard to the resulting layer homogeneity, i.e. local density and aggregate distribution in the cross‐section, and hardened concrete properties, i.e. flexural strength. By analysing the manufactured specimens, an uneven distribution of the aggregate is observed horizontally across the cross‐section of the layers. An accumulation of aggregate is present in the core of the layer resulting in a cement paste‐rich region in the edge areas. This leads to increased local densities in the core of the specimen. The application of the concrete with small nozzle outlet diameters results in the highest local densities and the highest flexural strength.

show abstract

“…In recent years, 3D printing of concrete has been increasingly adopted by the construction industry due to the new possibilities in component design and efficient use of materials. This can be seen in a large number of demonstration projects in the building and infrastructure sectors [1]. While the printing techniques are based on an automated fabrication process, the integration of reinforcement, which is essential for most structural elements, is often subject to manual process steps.…”

Section: Introductionmentioning

confidence: 99%

Enclosing Reinforcement Structures in Shotcrete 3D Printing

Freund,

Dörrie,

David

et al. 2023

Open Conf Proc

Self Cite

View full text Add to dashboard Cite

Integrating reinforcement into existing concrete 3D printing processes represents one of the key challenges in further automating the additive manufacturing of structural concrete components. A number of different approaches are currently being investigated. In this context, the integration of prefabricated reinforcement structures as well as the process-parallel assembly of reinforcement, e.g. by additive metal arc welding or joining of short rebars, are potential strategies. A common feature of both of these reinforcement strategies is that rebars protrude from the concrete surface in variable orientations during the printing process and need to be enclosed in concrete. Due to the spray application, Shotcrete 3D Printing (SC3DP) offers a good basis for realizing such reinforcement enclosures without the use of specially adapted nozzles. However, it is essential to systematically analyze material properties, e.g. accelerator dosage, and process properties, e.g. reinforcement orientation, in order to define limits for the application. For this reason, the present study investigates the influence of accelerator dosage (0 - 4 %) and reinforcement geometry (spacing, inclination, crossings) on the formation of voids. It is observed that with increasing accelerator dosage, the reinforcement structure increasingly acts as a blocking element for material spreading. The adhesion of the concrete to the reinforcement during spraying creates a shielding effect that increasingly leads to void formation. Finally, the potential and limitations of using prefabricated reinforcement structures in SC3DP are discussed.

show abstract

Digital Fabrication with Cement-Based Materials: Process Classification and Case Studies

Cited by 14 publications

References 49 publications

The Effects of Nozzle Diameter and Length on the Resulting Strand Properties for Shotcrete 3D Printing

The Effects of Nozzle Diameter and Length on the Resulting Strand Properties for Shotcrete 3D Printing

Shotcrete 3D Printing ‐ Interaction of nozzle geometry, homogeneity and hardened concrete properties

Enclosing Reinforcement Structures in Shotcrete 3D Printing

Contact Info

Product

Resources

About