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Investigation of Mechanical Properties of Structures Created with Use of Automatically Reinforced 3D Concrete Printing – Preliminary Study

Klik Przemysław, Cisowski Adam, Rządkowski Witold, Pyrzanowski Paweł, Kowalik Michał

Advances in Science and Technology. Research Journal

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2024

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Vol. 18, no 5

EN

3D concrete printing (3DCP) technology is a rapidly developing and promising technique for creating concrete structures. One of the main challenges of the 3DCP technology is the method of reinforcement, which should be integrated with the automated printing process, while maintaining the best mechanical properties important for the strength of the structure. The main reason to undertake the subject is low degree of automation in construction industry, which results in high cost of human labour, as well as high rate of accidents in process. The article proposes a technology for automatic reinforcement of concrete structures with glass fibres and epoxy resin. Maximum bending force tests of beams reinforced with the proposed method were carried out and compared with beams reinforced with commonly used methods. Although not being a article focused on DIC analysis, few images were presented to compare behaviour of non-reinforced beam with automatically reinforced one and to show cracking propagation of a chosen automatically reinforced beam. The proposed method of reinforcement in the 3DCP process enables full automation and constructions with high bending strength, simultaneously reducing the level of risk involved in conventional construction industry.

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Zaprawa modyfikowana cementem glinowym jako alternatywa dla standardowych materiałów używanych do druku 3D

Olczyk Norbert, Gierszewska Natalia, Skibicki Szymon

Builder

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2023

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R.27, nr 9

20--23

PL

Druk 3D betonu to innowacyjna technologia, która rewolucjonizuje branżę budowlaną. Ten zaawansowany proces pozwala na precyzyjne i zautomatyzowane wytwarzanie trwałych struktur z betonu, wykorzystując spoiwa na bazie cementu do druku. Druk 3D betonu oferuje wiele zalet. Po pierwsze, dzięki temu procesowi możliwe jest tworzenie niestandardowych kształtów i wzorów, które są trudne do osiągnięcia tradycyjnymi metodami budowlanymi. Ponadto, dzięki precyzyjnemu sterowaniu drukiem 3D można zminimalizować zużycie materiałów, co przekłada się na oszczędność kosztów i ograniczenie negatywnego wpływu na środowisko. Cement glinowy jako składnik spoiwa powoduje znaczne przyspieszenie czasu wiązania, co może być przydatne w technologii druku 3D. Przedstawione w artykule badania analizują możliwość wykorzystania cementu glinowego do modyfikacji mieszanki betonowej przeznaczonej do druku. Badania wykazały, że przy odpowiedniej kompozycji superplastyfikatora i spoiwa możliwe jest osiągnięcie wymaganych czasów wiązania.

EN

3D printing of concrete is an innovative technology that is revolutionizing the construction industry. This advanced process allows for the precise and automated production of durable concrete structures using cement-based binders for printing. 3D concrete printing offers many advantages. Firstly, thanks to this process, it is possible to create custom shapes and patterns that are difficult to achieve with traditional construction methods. Additionally, through precise control of 3D printing, the use of materials can be minimized, resulting in cost savings and a reduced negative environmental impact. Moreover, alumina cement as a binder component significantly accelerates the setting time, which can be useful in 3D printing technology. The research presented in the article analyzes the possibility of using alumina cement to modify the concrete mix intended for printing. Studies have shown that with the appropriate composition of superplasticizer and binder, it is possible to achieve the required setting times.

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Projektowanie i analiza mieszanki betonowej zawierającej kruszywo po obróbce strumieniowo-ściernej (garnet) w technologii druku 3D

Skibicki Szymon, Żygadło Alicja, Górnostaj Dariusz, Łabecka Magdalena, Orzelski Kamil

Builder

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2023

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R.27, nr 9

16--19

PL

Rozwój technologii druku 3D pozwala na zastosowanie go w wielu obszarach budownictwa, w tym w zakresie małej architektury. Celem pracy było zaprojektowanie i wykonanie w technologii druku 3D obiektu małej architektury - siedziska, z zastosowaniem mieszanki betonowej, w której kruszywo naturalne zostało zastąpione odpadem garnetu pochodzącym z obróbki strumieniowo-ściernej. Dotychczasowe prace w zakresie wykorzystania tego kruszywa pokazują, że istnieje możliwość jego utylizacji w druku 3D kompozytów cementowych. W celu realizacji zadania wykonano podstawowe badania materiałowe dla mieszanek o zawartości kruszywa z recyklingu do 50%. Kolejnym krokiem było wykonanie modelu siedziska i ustalenia potrzebnych wymiarów przekrojów dla prawidłowego funkcjonowania elementu. Finalnie wykonano siedzisko w technologii druku 3D. Projekt mieszanki został opracowany z myślą o wykorzystaniu odpadów, jednocześnie uwzględniając wymagania związane z drukiem betonowym w technologii 3D. Wykonanie elementu małej architektury z betonu drukowanego z kruszywem po obróbce strumieniowo-ściernej potwierdziło możliwość stosowania tej technologii. Badania stanowią wstęp do dalszych analiz uwzględniających optymalizację produktu oraz analizę jego trwałości.

EN

The development of 3D printing technology allows it to be used in many areas of construction. The work is aimed to design and manufacture a small architectural object using 3D printing technology, in the form of a seat. It is going to be made of a concrete mixture with aggregate waste after blasting and abrasive treatment (spent garnet). Previous work on this aggregate shows that it is possible to use it in the 3D printing of cement composites. Basic material tests were carried out for mixtures with recycled aggregate content of up to 50% to carry out the task. The next step was to make a model of the seat and determine the necessary cross-sectional dimensions for the correct functioning of the element. Finally, the seat was made using 3D printing technology. The mix design has been developed with waste in mind while taking into account the requirements of 3D concrete printing. The construction of an element of small architecture made of printed concrete with aggregate after blasting and abrasive treatment confirmed the possibility of using this technology. The research is a prelude to further analysis, including product optimization and durability analysis.

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Numerical modelling of planned corner deposition in 3D concrete printing

El Abbaoui K., Al Korachi I., Mollah M. T., Spangenberg J.

Archives of Materials Science and Engineering

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2023

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Vol. 121, nr 2

71--79

EN

Purpose: Analysis of different path planning strategies and the effects of changing printhead direction in the geometrical conformity and the process precision around 90° corner in order to enable a simple and cost-effective way of facilitating the determination of an optimal printing mode for fast and accurate print corners in 3D concrete printing. Design/methodology/approach: The material flow is characterized by a viscoplastic Bingham fluid. The printhead moves according to a prescribed speed to print the trajectory. The model solves the Navier-Stokes equations and uses the volume of fluid (VOF) technique. The acceleration steps and jerk (j) carry out the direction change. A smoothing factor is provided to smooth the toolpath. Several simulations were performed by varying the smoothing factor and jerk. Findings: Overfilling at the sharp corner was found when the printhead velocity was kept constant while extruding mortar at a fixed extrusion velocity; however, proportional extrusion velocity with the printhead motion has improved the quality of the corner. Otherwise, a slight improvement in the corner shape related to applying a jerk was found. Research limitations/implications: The Computational Fluid Dynamics (CFD) model could take an important amount of computing time to solve the problem; however, it serves as an efficient tool for accelerating different costly and time-consuming path planning processes for 3D concrete printing. Smaller angles and tilted printhead positions should be numerically and experimentally investigated in future research. Practical implications: The developed CFD model is suited for executing parametric studies in parallel to determine the appropriate printing motion strategy for each trajectory with corners. Originality/value: Computational Fluid Dynamics investigation of the path planning strategy for printing trajectory with a right-angle corner in 3D concrete printing.

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Reinforcements in 3D printing concrete structures

Alonso-Canon Sara, Blanco-Fernandez Elena, Castro-Fresno Daniel, Yoris-Nobile Adrian I., Castañon-Jano Laura

Archives of Civil and Mechanical Engineering

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2023

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Vol. 23, no. 1

art. no. e25, 2023

EN

3D printing of concrete structures has had a strong development in recent years, enhanced by the advantages it presents over traditional construction. However, it currently still has some limitations. One of those limitations is to incorporate the reinforcements into the automated 3D printing process. The objective of this work is to present a review of the methods that have been used so far to reinforce the structures. The different methods used will be presented focusing on the reinforcement by the use of fibers. The properties of the fibers, lengths, and percentages of the same used in the mixtures will be analyzed. The results of the different tests will be shown making a comparison between the values obtained from the tests carried out with the printed and molded materials. Finally, the increases in the results of the tests that these fibers provide with respect to the samples without them will be analyzed.

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Investigation of steel wire mesh reinforcement method for 3D concrete printing

Liu Miao, Zhang Qiyun, Tan Zhendong, Wang Li, Li Zhijian, Ma Guowei

Archives of Civil and Mechanical Engineering

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2021

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Vol. 21, no. 1

406--423

EN

3D concrete printing has received widespread attention and been developed for an increasing number of applications. However, a major challenge facing this technology is an effective way to introduce reinforcement into continuously deposited cementitious material. In this study, different layers of steel wire meshes (SWM) are employed to reinforce the 3D printed structures to improve mechanical capacities. Both destructive (bending, compression and splitting) and non-destructive (using electro-mechanical impedance) tests are employed to characterize the impact of this reinforcement method. The damage accumulation process is measured through the smart PZT patches based on the electro-mechanical impedance method. The results indicate that reinforced 3D-printed components with SWM change their failure modes from brittle to ductile. The peak loads are increased by 59.2–173.3% and the deflection capacity can be increased by more than 11 times than the non-reinforced one. Different mechanical responses of print and cast samples under compression are studied. The splitting tensile strength of wire mesh reinforced concrete is also measured, which is 43.7% higher than the non-reinforced sample. The calculating methods of the cracking moment and ultimate moment of steel wire mesh reinforced 3D printed concrete are presented. Comparison between the calculated and the experimental results verifies the effectiveness in predicting the ultimate moment. Experimental results show that it is feasible and effective to employ steel wire mesh for strength and toughness enhancement of 3D printed structures.

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Mechanical behaviors of 3D printed lightweight concrete structure with hollow section

Wang Li, Jiang Hailong, Li Zhijian, Ma Guowei

Archives of Civil and Mechanical Engineering

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2020

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Vol. 20, no. 1

219--235

EN

A practical revolution in construction could be realized by combining the potential of 3D concrete printing with lightweight cementitious materials to fabricate adeptly hollow structures. In this study, five concrete mixtures with different replacement rates of lightweight ceramsite sand to silica sand are prepared for extrusion-based 3D printability evaluation. To reduce the water absorption induced shrinkage and micro-cracks, the ceramsite sands were coated with polyvinyl alcohol. An optimized cementitious material was identified by harmonizing the fresh properties to the continuous printing process. Cubic and beam elements with four different types of interior hollow structures were designed and 3D printed based on the optimized lightweight mixture. The interior structures include cellular-shaped structure, truss-like structure, lattice-shaped structure with a square topology, as well as gridding shaped structure with triangle topology. The mechanical capacities of the printed samples were measured and evaluated by compressive tests for the cubic samples and four-points flexural bending tests for the beam specimens. Basing on the results, the rectangular lattice hollow structure demonstrates the best mechanical resistance to compression and the truss-shaped prism structure ensues the highest flexural properties. The stress distribution and failure process were also explored through discrete element method.

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Fresh and hardened properties of 3D printable cementitious materials for building and construction

Paul S. C., Tay Y. W. D., Panda B., Tan M. J.

Archives of Civil and Mechanical Engineering

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2018

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Vol. 18, no. 1

311--319

EN

The main advantage of 3D concrete printing (3DCP) is that it can manufacture complex, non-standard geometries and details rapidly using a printer integrated with a pump, hosepipe and nozzle. Sufficient speed is required for efficient and fast construction. The selected printing speed is a function of the size and geometrical complexity of the element to be printed, linked to the pump speed and quality of the extruded concrete material. Since the printing process requires a continuous, high degree of control of the material during printing, high performance building materials are preferred. Also, as no supporting formwork is used for 3DCP, traditional concrete cannot be directly used. From the above discussion, it is postulated that in 3DCP, the fresh properties of the material, printing direction and printing time may have significant effect on the overall load bearing capacity of the printed objects. The layered concrete may create weak joints in the specimens and reduce the load bearing capacity under compressive, tensile and flexural action that requires stress transfer across or along these joints. In this research, the 3D printed specimens are collected in different orientations from large 3DCP objects and tested for mechanical properties. For the materials tested, it is found that the mechanical properties such as compressive and flexural strength of 3D printed specimen are governed by its printing directions.