Abstract
The construction sector is undergoing a paradigm change towards sustainability and innovation, with 3D Mortar Printing (3DCP) emerging as an exciting new technology. This research project investigates the use of Larox filter cake, a mining industry byproduct, as a partial replacement for traditional cement in 3D printed mortar. Larox-based mortar offers a once-in-a-lifetime potential to reduce environmental impact, improve structural performance, and expand the scope of sustainable construction practises.
The properties investigated were particle size distribution, workability, extrudability, buildability, open time, compressive strength, flexural strength, dry shrinkage, wet density and dry density. The findings showed that Larox filter cake has the potential to improve the flexural and compressive strength of 3D printed mortar while lowering its carbon footprint. Furthermore, Larox-based mortar is extremely workable, making it an excellent alternative for complicated and customised 3D printed constructions.
In this study, Larox filter cake waste was added as a partial OPC replacement, and properties of the OPC were examined. The characteristics of mortar samples including the filter-cake components and OPC were examined using X-ray diffraction, Fourier Transform-Infrared Spectroscopy, Mineralogical Analysis, and Calorimetry. At curing ages of 1, 3, 7 and 28 days, the flexural and compressive strengths of OPC-mortar samples were improved. At day 1, 5%-LAR compressive strength showed an improvement of 16% compared to the reference mix with 0%-LAR Larox content. At day 3, 5%-LAR improved by 22% while the flexural improved by an average of 28%. At day 7, 5%-LAR increased by 7% to the reference mix. At 28 days of curing age, the average flexural strength was increased by 10% and compressive strengths of Larox with 5% increased by 6%. The mechanical qualities of blended mortars made from 15% to 20% Larox and 80% to 85% OPC, however, did not improved.
Although extrusion printing is the most effective technique for printing cementitious materials, it still has many difficulties, including pumpability, buildability and consistency. In order to get the best mechanical strength for printed mortar and to produce adequate flowability and consistent workability for the mixed cementitious
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mortar during the printing process, the trial mixes were examined. It was fundamental to examine the mechanical characteristics and behaviour of the cementitious mix's proportions. A caulking gun with an 18 mm nozzle size was used to test for buildability and extrudability. 10%-LAR with the adequate rheology properties need for 3D printing was optimised to be extrudable with no nozzle blockage or cracks. The mix also managed to print 15 layers of 30 mm mortar strips.
The findings highlight Larox filter cake's suitability as a cement alternative in 3DCP, with the potential to revolutionise the industry by fostering eco-friendly practises and novel design options. The use of Larox-based mortar in 3D printing lays out the possibility of a more sustainable and resilient future in construction. The notable high content of gypsum in Larox filter cake, makes it advisable to produce a cement by combining the material with a clinker.