Browsing by Keyword "3D printing"
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Item Electrical Conductive Properties of 3D-PrintedConcrete Composite with Carbon Nanofibers(2022-11) Goracci, Guido; Salgado, David M.; Gaitero, Juan J.; Dolado, Jorge S.; Tecnalia Research & Innovation; ECOEFICIENCIA DE PRODUCTOS DE CONSTRUCCIÓNElectrical conductive properties in cement-based materials have received attention in recent years due to their key role in many innovative application (i.e., energy harvesting, deicing systems, electromagnetic shielding, and self-health monitoring). In this work, we explore the use 3D printing as an alternative method for the preparation of electrical conductive concretes. With this aim, the conductive performance of cement composites with carbon nanofibers (0, 1, 2.5, and 4 wt%) was explored by means of a combination of thermogravimetric analysis (TGA) and dielectric spectroscopy (DS) and compared with that of specimens prepared with the traditional mold method. The combination of TGA and DS gave us a unique insight into the electrical conductive properties, measuring the specimens’ performance while monitoring the amount in water confined in the porous network. Experimental evidence of an additional contribution to the electrical conductivity due to sample preparation is provided. In particular, in this work, a strong correlation between water molecules in interconnected pores and the (Formula presented.) values is shown, originating, mainly, from the use of the 3D printing technique.Item Life cycle assessment (LCA) and multi-criteria decision-making (MCDM) analysis to determine the performance of 3D printed cement mortars and geopolymers(2022-07-19) Yoris-Nobile, Adrian I.; Lizasoain-Arteaga, Esther; Slebi-Acevedo, Carlos J.; Blanco-Fernandez, Elena; Alonso-Cañon, Sara; Indacoechea-Vega, Irune; Castro-Fresno, Daniel; Tecnalia Research & Innovation; ECONOMÍA CIRCULARA comparison between low-clinker cement and geopolymer mortars for their application in 3 D printing is discussed in this paper. The mortars are composed of materials with low environmental impact, such as cements with low clinker content, by-products of the industry and recycled aggregates. The developed mortars were both mechanically and rheologically characterized. The environmental impact was studied by LCA. To select the most suitable dosages, MCDM analysis was applied based on cost of materials, printability and LCA. Compressive strength was considered as a normalizing parameter for both the LCA and cost. The mortars showed good printability and suitable mechanical strength, being higher in the cement mortars. The LCA showed that the geopolymer mortars have a higher environmental impact due to the use of sodium hydroxide. Likewise, MCDM revealed that low-clinker cement mortars are at the top of the ranking, due to a lower environmental impact and lower cost of materials.Item Obtaining preforms by additive fused deposition modelling (FDM) extrusion technology for the manufacture of high-performance composites(2022-06) Mendizabal, M. A.; Garcia, Maitane; Palenzuela, Luis; Hernández, Enrique; POLIMEROS; Tecnalia Research & Innovation; COMPOSITEThe composites industry is present in practically all industrial sectors with an annual growth rate of 5%. Its contribution to the priority "light-weighting" driver in the transport sector is key. The efficiency of the industry is made possible by the evolution of manufacturing processes that also improve the performance of the products obtained. For example, out-of-autoclave (OOA) processes can obtain high-performance composites such as those obtained by the autoclave process at lower costs. A key aspect in the development of this type of process is the preforming of continuous fibre reinforcements, which can achieve high fibre percentages while facilitating processing. Manufacturing these preforms currently requires multiple steps, equipment and tooling. TECNALIA's work developing the ADDICOMP technology, an alternative preform manufacturing method using an additive process based on Fused Deposition Modelling (FDM) is detailed in this article. This development is patented by Tecnalia and was conducted in 2 phases: (a) development of continuous fibre filaments coated with polymeric material and printable by FDM and (b) fine-tuning of FDM technology to print filaments with a very high content of continuous fibre.