Talk:3D concrete printing

Binder Jetting / State of the art
Deveop this sections with a review of type of inovation:

Materials science section to be added for layered extrusion
Rheology of concrete: acceleration control. The material preparation stage includes mixing and placing the concrete into the container. Once the fresh concrete has been placed into the container, it can be conveyed through the pump–pipe– nozzle system to print out self-compacting concrete filaments, which can build layer-by-layer structural components. In the additive processes, pumpability and the stability of the extrusion is important for the applications of mortars. These properties will all vary depending on the concrete mix design, the delivery system, and the deposition device. General specifications of wet concrete 3D printing are categorized into four main characteristics: Pumpability: The ease and reliability with which material is moved through the delivery system Printability: The ease and reliability of depositing material through a deposition device Buildability: The resistance of a deposited wet material to deformation under load Open time: The period where the above properties are consistent within acceptable tolerances. To execute the printing process, a control system is required. These systems can be generally split into two categories: gantry systems and robotic arm systems. The gantry system drives a manipulator mounted onto an overhead to locate the print nozzle in XYZ cartesian coordinates while robotic arms offer additional degrees of freedom to the nozzle, allowing more accurate printing workflows such as printing with tangential continuity method. Regardless of the system used for printing (gantry crane or robotic arm), the coordination between the nozzle travel speed and the material flow rate is crucial to the outcome of the printed filament. In some cases, multiple 3D printing robotic arms can be programmed to run simultaneously resulting in decreased construction time. Finally, automated post-processing procedures can also be applied in scenarios which require the removal of support structures or any surface finishing.

The researchers at Purdue University have pioneered a 3D printing process known as Direct-ink-Writing for fabrication of architectured cement-based materials for the first time. They demonstrated using 3D-printing, bio-inspired designs of cement-based materials is feasible and novel performance characteristics such as flaw-tolerance and compliance can be achieved.

Add Applications section
Bricks / Discrete building elements

Columns

Walls

Bridges

Floor slabs

Street furniture

Water tanks

Stairs

Opportunities and Challenges Section
Potential advantages of these automation technologies include faster construction, lower costs, ease of construction, enabling DIY construction, increased complexity and/or accuracy, greater integration of function, and less waste produced.

Opportunities
Geometric freedom, bespoke geometries suitable for one of a kind objects Large-scale, cement-based 3D printing disposes the need for conventional molding by precisely placing, or solidifying, specific volumes of material in sequential layers by a computer controlled positioning process. This 3D printing approach consist of three general stages: data preparation, concrete preparation and component printing.

Challenges
cost, infrastructure necessary compliance with building codes surface texture Binder jet 3D concrete printing has seen limited use in functional architecture or infrastructure projects. This is mainly due to the incompatibility of the layered fabrication process with the integration of the necessary continuous steel reinforcement bars regularly required for taking tensile loads in concrete parts. Furthermore, this is a relatively new material that is not yet covered in building codes. The incorporation of reinforcement is difficult, as steel rebar must not impede the movement of the printer head. This issue is addressed by printing hollow structures to place rebar afterward, with infilled concrete making the connection to the printed structure. This renders the process as essentially a stay-in-place formwork production process.

Reinforcement
See also: Reinforcement in concrete 3D printing While parts with the structural capacity of unreinforced Portland cement can be printed [20], again the introduction of reinforcement remains problematic.

Add section on Robotic shotcrete
https://doi.org/10.1007/978-3-319-99519-9_27

Add review on universities, startups, companies
by continent? Asia, Australia, Europe, North America

Stratocaster47 (talk) 14:42, 25 May 2022 (UTC)

Commons files used on this page or its Wikidata item have been nominated for deletion
The following Wikimedia Commons files used on this page or its Wikidata item have been nominated for deletion: Participate in the deletion discussions at the nomination pages linked above. —Community Tech bot (talk) 21:37, 18 December 2022 (UTC)
 * Construction of ICON homes in Georgetown, TX.jpg (discussion)
 * History of 3DCP.jpg (discussion)
 * Lavacrete concrete mix designed by ICON.png (discussion)