Abstract
With the rapid advancement of 3D printing technology, which provides creative and eco-friendly building solutions, the construction sector has undergone a radical change. The integration of recycled broken clay bricks into 3D printed concrete is the subject of this investigation, it seeks to explore and develop the integration of recycled crushed clay bricks in 3D concrete printing processes as one of the best methodologies towards addressing the growing demand for sustainable construction materials. Traditionally, formwork has been used to pour concrete into while building concrete structures. This strategy still works, but where it is practical, technology must be included to improve the speed and cost-effectiveness of the construction process. Clay bricks are traditionally produced using a lot of energy and produce a lot of waste. Brick production's energy consumption and trash output can be reduced by employing crushed clay bricks as aggregate substitute in construction 3D concrete printing. With recycled crushed clay bricks as its main component, the study examines the mechanical characteristics and structural soundness of 3D printed constructions. It investigates the ideal proportions of broken clay bricks to additional binders and additives to ensure the necessary strength and longevity of the printed constructions. Thus, this study is of immense importance because in the construction arena, eco-friendly developments are desperately required for averting environmental deterioration. In the traditional building material, there generally exists resource depletion and waste generation of higher order which calls for some novel ideas into sustainable development studies. To achieve results, the study employed a comprehensive number of tests which included material characterization, mix design optimization as well as 3D printing trials. The properties of physical and chemical, further need to access for these recycled crushed clay bricks to acquire their physical and chemical composition, to make sure that both can be compatible with the concrete mixtures. Afterwards, there was investigation for structural and mechanical performance of materials to be printed by 3D concrete printer. The study investigated the effects of using Crushed Clay Bricks (CCB) in place of silica sand in 3D-printed concrete. Concrete workability dropped as CCB replacement rose; Mix 3 showed the best workability at 30% CCB substitution. The replacement percentage had an impact on extrudability; combinations over 40% demonstrated poor extrudability, which resulted in problems including segregation. Buildability varied, preferring filament layer development with smaller replacement rates. The incorporation of CCBs affected the setting timeframes; Mix 7 displayed the highest at 190 minutes with 90% substitution. After 28 days, Mix 3, which had 30% CCB and a 0.36 water/binder ratio, had the maximum compressive strength at 45.52
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MPa. Mix 3's flexural strength was at its peak, surpassing the target threshold at 11.75 MPa. Combinations over 40% in CCB replacement fell short of strength requirements. As CCB replacement increased, drying shrinkage also increased. The study found that the best mix for 3D concrete printing using recycled crushed clay bricks is Mix 3, which has a 30% CCB replacement and a 0.36 water/binder ratio. The study suggests using recycled crushed clay bricks (CCB) as a sustainable building material for 3D printing. Workability evaluations show the need for mix design modifications to improve workability and extrudability. Further research is needed to balance workability, extrudability, and strength. Prewetting of aggregates and using additives can also improve concrete mix flow characteristics. The study recommends exploring other cementitious materials and waste materials for improved durability. Automatic 3D printers are recommended for further studies.