Dynamic Properties and Fractal Characteristics of 3D Printed Cement Mortar in SHPB Test.

Yixin Mo,Xiao Liu,Qizhen Zhou,Bowei Feng,Songlin Yue

doi:10.3390/ma14195554

Yixin Mo, Xiao Liu + Show 3 more

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https://doi.org/10.3390/ma14195554

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Abstract

Comparing with the traditional construction process, 3D printing technology used in construction offers many advantages due to the elimination of formwork. Currently, 3D printing technology used in the construction field is widely studied, however, limited studies are available on the dynamic properties of 3D printed materials. In this study, the effects of sand to binder ratios and printing directions on the fractal characteristics, dynamic compressive strength, and energy dissipation density of 3D printed cement mortar (3DPCM) are explored. The experiment results indicate that the printing direction has a more significant influence on the fractal dimension compared with the sand to binder ratio (S/B). The increasing S/B first causes an increase and then results in a decline in the dynamic compressive strength and energy dissipation of different printing directions. The anisotropic coefficient of 3DPCM first is decreased by 20.67%, then is increased by 10.56% as the S/B increases from 0.8 to 1.4, showing that the anisotropy is first mitigated, then increased. For the same case of S/B, the dynamic compressive strength and energy dissipation are strongly dependent on the printing direction, which are the largest printing in the Y-direction and the smallest printing in the X-direction. Moreover, the fractal dimension has certain relationships with the dynamic compressive strength and energy dissipation density. When the fractal dimension changes from 2.0 to 2.4, it shows a quadratic relationship with the dynamic compressive strength and a logarithmic relationship with the energy dissipation density in different printing directions. Finally, the printing mortar with an S/B = 1.1 is proved to have the best dynamic properties, and is selected for the 3D printing of the designed field barrack model.

Highlights

With the development of the global construction industry, traditional construction is facing the problems of environmental pollution, a shortage of labor, overuse of raw materials, etc. [1,2]
Pressure Bar (SHPB) test (Table 2); limited studies are available on the dynamic properties of 3D printed cementitious materials using a SHPB
The purpose of this work is to investigate the effects of sand to binder ratio (S/B) and printing direction on the fractal features and dynamic behaviors of 3D printed cement mortar (3DPCM)

Summary

Introduction

With the development of the global construction industry, traditional construction is facing the problems of environmental pollution, a shortage of labor, overuse of raw materials, etc. [1,2]. Compared with the traditional construction process, 3D printing technology, as used in construction, has the advantages of high design flexibility, short construction periods for the single irregularly shaped components, and lower resource consumption due to the elimination of formwork [3,4,5]. These advantages of 3D printing techniques can resolve a series of problems faced by traditional construction [6]. Similar results were found in terms of the tensile, bending and shearing strength [14]

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Results

Conclusion