The development of printers and materials for 3D Printing Construction during the last two decades has allowed the construction of increasingly complex projects. Some of them have broken construction speed records due to the simplification of the construction process, particularly in non-standard geometries. However, for performance and security reasons the materials used had considerable amounts of Portland cement (PC), a constituent that increases the cost and environmental impact of 3D Printable Materials (3DPM). Supplementary Cement Materials (SCM), such as fly ash, silica fume and metakaolin, have been considered a good solution to partially replace PC. This work aims to study the inclusion of limestone filler, fly ash and metakaolin as SCM in 3DPM. Firstly, a brief literature review was made to understand how these SCM can improve the materials’ 3DP capacity, and which methods are used to evaluate them. Based on the literature review, a laboratory methodology is proposed to assess 3DP properties, where tests such as slump and flow table are suggested. The influence of each SCM is evaluated by performing all tests on mortars with different dosages of each SCM. Finally, a mechanical extruder is used to extrude the developed mortars, which allowed us to compare the results of slump and flow table tests with the quality of extruded samples.
2 March 2021 in Proceedings of the Institution of Mechanical Engineers, Part L: Journal of Materials: Design and Applications
In construction, three-dimensional concrete printing technology is an innovative method that opens new design possibilities, reducing the construction time process. The incremental material deposition allows organic shapes without formwork, a mandatory constraint in preparatory phases of conventional complex concrete structures. Nowadays, in three-dimensional printing for construction industry, concrete is the most used material due to its workability, extrudability, and pumpability properties favorable for the printing conditions. Hence, this composition still has a poor sustainable efficiency due to the high levels of Portland Cement. In this research, a reduction of this material was studied and experimented searching for a mortar composition with better ecological footprint, with the objective of decreasing the CO2 emissions. A bibliometric analysis was made to study the constituents of a mortar for three-dimensional printing and respective dosage. The knowledge acquired in the analysis of the compositions contributed to the development of mortars with lower Portland Cement content. A mechanical extruder was used to check the extrusion capacity of the developed mortars, and the best compositions are presented.
As concrete revolutionised construction in the 20th century, digitalisation is transforming the building industry (BI). Process automation and 3D printing (3DP) are commonplace in the industry and our homes. However, due to BI’s scale and complexity, Additive Manufacturing (AM) is in its native stage. Ongoing scientific research has been providing knowledge that will simplify the integration of 3DCP in the market, exploring its materiality, technologies, and design methodologies. This book provides an overview of the latest research achievements of the design possibilities that 3DP for construction (3DC) can offer in the various fields of construction, particularly architecture and engineering. <!----> <!----> <!----> <!---->