Technical Report Parts

3D printing is an additive technology used to manufacture parts. It is ‘additive’ because it doesn’t require a block of material or a mold to manufacture parts, it stacks and fuses layers of material. It is typically fast, with low fixed setup costs, and can create more complex objects than ‘traditional’ technologies, with an extensive list of materials that can be used (TWI, 2019). This process of additive manufacturing is the direct opposite of traditional subtractive manufacturing, which refers to a final design being cut out from a block of material (Hubs, n.d.)

3D printing is an additive technology used to manufacture parts. According to Carmel (2020), there are few options for 3D printing in the construction industry, with the likes of robotic arm extruders, sand 3D printing and metal technology. For the robotic arm extruders it is very similar to the Fused Deposition Modelling (FDM) 3D printing, for sand 3D printing it is similar to the Selective Laser Sintering (SLS) and jet fusion method, while for metal technology is a robot that allows for 3D printing of metal structures in 6-axes (Carmel, 2020).

FDM is a material extrusion method of manufacturing, where materials are extruded from a nozzle and joined together to form 3D objects (Carolo, 2022). For the robotic arm extruders, the arm will build the house by layers, through the extrusion of concrete materials from the nozzle (Carmel, 2020). 3D printing concrete requires the use of large-scale 3D printers, often measuring 30 feet in height and length and extruding a dough-like concrete which is laid down in layers to create a building element (Kauppila, 2023).(Refer to appendix D to see how a 3D printed structure looks) 

SLS is a form of 3D printing that uses a high-powered laser to sinter small particles of polymer powder into a solid structure (Formlabs, n.d.). For jet fusion printers, the fusion print head deposits binding droplets and detailing agents across the layers of powders that have been preheated, with the binder serving as a heat-absorbing ink that allows the powder to melt easily to what it binds to (Weerg, 2021).

For metal technology, Wire Arc Additive Manufacturing (WAAM) is a process to 3D print or repair metal parts, it is a form of Direct Energy Deposition (DED) additive manufacturing process. WAAM is executed by depositing layers of metal on top of one another until the desired model is achieved (RAMLAB, 2022). DED is a complex 3D printing process, usually used to repair or add additional materials to existing parts. With it being able to completely manufacture new parts from scratch or conduct repairs on components (V, 2022).

As observed from a study conducted by Nanyang Technological University (NTU), where an experiment had been conducted on the flexural strength of 3D printed concrete and traditional concrete. In the figures(See Appendix A), it can be seen that the 3D  printed concrete has a higher compressive strength and flexural strength than the regular concrete material (Zhang et al., 2020).  (T1/T2/T3 represents the 3D printed concrete and MC represents the normal concrete). Using 3D printers, other elements can be added to the concrete mixture before it is extruded through the nozzle to create the structure. By adding micro silica, the compressive strength and ultimate flexural strength of the concrete extruded and increased the flowability of the composite (Singh, 2021).