Extrusion-Based 3D Printing Concrete with Coarse Aggregate (2021-05)¶

Printability and Direction-Dependent Mechanical Performance

10.1016/j.conbuildmat.2021.123624

Chen Yidong, Zhang Yunsheng, Pang Bo, Liu Zhiyong, Liu Guojian
Journal Article - Construction and Building Materials, Vol. 296

Abstract

Concrete with coarse aggregate in the 3D concrete printing (3DCP) has broad prospects for high strength, low cost and shrinkage. In this study, an extrusion-based 3D printer was designed and utilized to print concrete with the largest aggregate size of 20 mm. Printable concrete with coarse aggregate was designed by different volume ratios of cement to aggregate (C/A). Then the effect of C/A on the printability and direction-dependent mechanical performance was investigated. X-ray micro-computed tomography (X-CT) was used to detect and analyze the voids distribution characteristics of printed specimens. Scanning electron microscope (SEM) investigations of microstructure at the interlayer area were conducted. Results indicated that the initial flowability of printable concrete should be within 178– 200 mm, and the recommended printable C/A was within 0.35–0.60. The decrease of C/A improved the maximum printing height and mechanical performance but weakened the shape-stability of the multilayer structure. X-CT results indicated that reducing excess slurry content caused by the decline of C/A decreased the compactness of the printed structure. The compressive strength and flexural strength of 3D printed specimens showed a direction-dependent characteristic, mainly related to the non-uniform distribution of voids revealed by X-CT. SEM images revealed the ‘‘micro-bridging” morphology in the interlayer area and proved that there were carbonation and structural weakening problems at the surface and surrounding of this area.

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40 References

88 Citations

BibTeX

@article{chen_zhan_pang_liu.2021.EB3PCwCA,
  author            = "Yidong Chen and Yunsheng Zhang and Bo Pang and Zhiyong Liu and Guojian Liu",
  title             = "Extrusion-Based 3D Printing Concrete with Coarse Aggregate: Printability and Direction-Dependent Mechanical Performance",
  doi               = "10.1016/j.conbuildmat.2021.123624",
  year              = "2021",
  journal           = "Construction and Building Materials",
  volume            = "296",
}

Formatted Citation

IEEE

Y. Chen, Y. Zhang, B. Pang, Z. Liu and G. Liu, “Extrusion-Based 3D Printing Concrete with Coarse Aggregate: Printability and Direction-Dependent Mechanical Performance”, Construction and Building Materials, vol. 296, 2021, doi: 10.1016/j.conbuildmat.2021.123624.

CMOS

Chen, Yidong, Yunsheng Zhang, Bo Pang, Zhiyong Liu, and Guojian Liu. “Extrusion-Based 3D Printing Concrete with Coarse Aggregate: Printability and Direction-Dependent Mechanical Performance”. Construction and Building Materials 296 (2021). https://doi.org/10.1016/j.conbuildmat.2021.123624.