Nanyang Technological University researches building 3D printing with a large amount of ash mixture

Nanyang Technological University student Biranchi Panda, in the recently published “3D Printing of High-Volume Fly Ash Mixtures for Digital Concrete Buildings”, explored how to improve fly ash-based geopolymers and use them for 3D construction. Print. Concrete is one of the most widely used materials in the world, and contractors can now choose from fiber-reinforced, polymer-made and even self-compacting materials. There are many benefits of using SCC, including fluidity, surface quality, durability, etc. However, the manufacture of complex geometric shapes is still challenging, requires increased costs and requires more manpower.

3D Printing has not only attracted the attention of industrial users in the construction industry, but as a faster, more affordable, and more versatile technology than conventional methods, it has also quickly attracted attention. The 3D printing system usually includes:

• 1. Material mixing tank
• 2. Pumping system
• 3. Extrusion system, print head with nozzle
• 4. Electronic control box
• 5. Safety system.

Factors affecting the performance and performance of fly ash concrete. Geological aggregation Compared with computer-aided design (CAD), the graphical model of physical alkalization has the advantages of better topology optimization, more design opportunities, fast manufacturing speed, and the ability to construct items that may not be included. This technology also has the potential to reduce the environmental impact of 3D printing, which is another positive benefit, as cement production currently accounts for 5% of global CO2 production. At present, sustainable materials based on fly ash look very attractive because they can produce 80% less carbon dioxide emissions than ordinary Portland cement and have higher mechanical properties.
As we all know, thixotropy is one of the important characteristics of all 3D printing projects. Due to flocculation, PC has inherent excellent thixotropy. In the presence of any foreign matter (such as FA, sand, fillers), its colloidal network will rupture, resulting in loss of thixotropy. One such example is the high fly ash (HVFA) material, which not only has low thixotropy, but also hardens slowly. Despite its sustainability, poor early mechanical properties limited its application in 3D printing projects. ”

A) D-printer and (b) the final printed part with all excess raw materials
This problem is that Biranchi Panda enters the current research direction, hoping to improve the printability of HVFA adhesives and have a comprehensive understanding of HVFA cement and geopolymers. The first step Panda considered was to create a flowable extruded material to maintain its shape throughout the process. When using 3D printing, the process can be carried out directly on a construction site or another location where prefabricated parts are put together and then transported for assembly.
Fine sand pho is used to prepare mortar because it is easily available in Singapore. The mixture prepared by Panda and the research team can improve thixotropy because they can measure compressive, flexural and tensile strength. Microstructure analysis was also carried out. Ultimately, fly ash cement is considered “printable.”