Study of MgO-activated slag as a cementless material for sustainable spray-based 3D printing

3D concrete printing technology greatly facilitates automation in construction which enhances efficiency, productivity and sustainability. This study develops a slag-based mixture as a cementless material for sustainable spray-based 3D printing. Effects of MgO and fly ash cenosphere (FAC) addition o...

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Main Authors: Lu, Bing, Zhu, Weiping, Weng, Yiwei, Liu, Zhixin, Yang, En-Hua, Leong, Kah Fai, Tan, Ming Jen, Wong, Teck Neng, Qian, Shunzhi
Other Authors: School of Mechanical and Aerospace Engineering
Format: Article
Language:English
Published: 2021
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Online Access:https://hdl.handle.net/10356/148288
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Institution: Nanyang Technological University
Language: English
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spelling sg-ntu-dr.10356-1482882021-05-08T20:11:41Z Study of MgO-activated slag as a cementless material for sustainable spray-based 3D printing Lu, Bing Zhu, Weiping Weng, Yiwei Liu, Zhixin Yang, En-Hua Leong, Kah Fai Tan, Ming Jen Wong, Teck Neng Qian, Shunzhi School of Mechanical and Aerospace Engineering School of Civil and Environmental Engineering Singapore Centre for 3D Printing Engineering Additive Manufacturing Sustainability 3D concrete printing technology greatly facilitates automation in construction which enhances efficiency, productivity and sustainability. This study develops a slag-based mixture as a cementless material for sustainable spray-based 3D printing. Effects of MgO and fly ash cenosphere (FAC) addition on setting, hydration and rheological properties of fresh mixtures are investigated to obtain the optimal mixture. Results show that inclusion of MgO effectively reduces initial setting time of the fresh mixtures. With 40 wt% of GGBS replaced by MgO, initial setting time is greatly reduced from 305 min to 67 min (78% reduction). Fourier-Transformed Infrared (FTIR) spectra suggest the acceleration is plausibly due to the physical aspects. Furthermore, the FTIR spectra show that MgO can effectively activate the slag and also improve water retention. Rheological tests reveal that FAC addition generally reduces dynamic yield stress and plastic viscosity while increases static yield stress of the fresh mixtures, resulting in lower pumping pressures and higher critical ratios. The mixture with 20 wt%/40 wt% FAC addition has 29%/31% lower pumping pressure and 78%/68% higher critical ratio compared with plain MgO-activated slag material, respectively. Hence, the material with tailored rheology leads to better delivery and deposition performance of the mixture and overall spray-printing quality. An optimal mixture was finally selected based on setting, hydration, rheological properties and spray performance. The developed cementless mixture was successfully applied in the vertical spray-based 3D printing of filament and profile, which confirmed its feasibility in engineering applications. National Research Foundation (NRF) Accepted version 2021-05-03T07:37:30Z 2021-05-03T07:37:30Z 2020 Journal Article Lu, B., Zhu, W., Weng, Y., Liu, Z., Yang, E., Leong, K. F., Tan, M. J., Wong, T. N. & Qian, S. (2020). Study of MgO-activated slag as a cementless material for sustainable spray-based 3D printing. Journal of Cleaner Production, 258, 120671-. https://dx.doi.org/10.1016/j.jclepro.2020.120671 0959-6526 https://hdl.handle.net/10356/148288 10.1016/j.jclepro.2020.120671 2-s2.0-85079642072 258 120671 en Journal of Cleaner Production © 2020 Elsevier Ltd. All rights reserved. This paper was published in Journal of Cleaner Production and is made available with permission of Elsevier Ltd. application/pdf
institution Nanyang Technological University
building NTU Library
continent Asia
country Singapore
Singapore
content_provider NTU Library
collection DR-NTU
language English
topic Engineering
Additive Manufacturing
Sustainability
spellingShingle Engineering
Additive Manufacturing
Sustainability
Lu, Bing
Zhu, Weiping
Weng, Yiwei
Liu, Zhixin
Yang, En-Hua
Leong, Kah Fai
Tan, Ming Jen
Wong, Teck Neng
Qian, Shunzhi
Study of MgO-activated slag as a cementless material for sustainable spray-based 3D printing
description 3D concrete printing technology greatly facilitates automation in construction which enhances efficiency, productivity and sustainability. This study develops a slag-based mixture as a cementless material for sustainable spray-based 3D printing. Effects of MgO and fly ash cenosphere (FAC) addition on setting, hydration and rheological properties of fresh mixtures are investigated to obtain the optimal mixture. Results show that inclusion of MgO effectively reduces initial setting time of the fresh mixtures. With 40 wt% of GGBS replaced by MgO, initial setting time is greatly reduced from 305 min to 67 min (78% reduction). Fourier-Transformed Infrared (FTIR) spectra suggest the acceleration is plausibly due to the physical aspects. Furthermore, the FTIR spectra show that MgO can effectively activate the slag and also improve water retention. Rheological tests reveal that FAC addition generally reduces dynamic yield stress and plastic viscosity while increases static yield stress of the fresh mixtures, resulting in lower pumping pressures and higher critical ratios. The mixture with 20 wt%/40 wt% FAC addition has 29%/31% lower pumping pressure and 78%/68% higher critical ratio compared with plain MgO-activated slag material, respectively. Hence, the material with tailored rheology leads to better delivery and deposition performance of the mixture and overall spray-printing quality. An optimal mixture was finally selected based on setting, hydration, rheological properties and spray performance. The developed cementless mixture was successfully applied in the vertical spray-based 3D printing of filament and profile, which confirmed its feasibility in engineering applications.
author2 School of Mechanical and Aerospace Engineering
author_facet School of Mechanical and Aerospace Engineering
Lu, Bing
Zhu, Weiping
Weng, Yiwei
Liu, Zhixin
Yang, En-Hua
Leong, Kah Fai
Tan, Ming Jen
Wong, Teck Neng
Qian, Shunzhi
format Article
author Lu, Bing
Zhu, Weiping
Weng, Yiwei
Liu, Zhixin
Yang, En-Hua
Leong, Kah Fai
Tan, Ming Jen
Wong, Teck Neng
Qian, Shunzhi
author_sort Lu, Bing
title Study of MgO-activated slag as a cementless material for sustainable spray-based 3D printing
title_short Study of MgO-activated slag as a cementless material for sustainable spray-based 3D printing
title_full Study of MgO-activated slag as a cementless material for sustainable spray-based 3D printing
title_fullStr Study of MgO-activated slag as a cementless material for sustainable spray-based 3D printing
title_full_unstemmed Study of MgO-activated slag as a cementless material for sustainable spray-based 3D printing
title_sort study of mgo-activated slag as a cementless material for sustainable spray-based 3d printing
publishDate 2021
url https://hdl.handle.net/10356/148288
_version_ 1699245904738910208