TY - JOUR
T1 - Insights into material design, extrusion rheology, and properties of 3D-printable alkali-activated fly ash-based binders
AU - Alghamdi, Hussam
AU - Nair, Sooraj A.O.
AU - Neithalath, Narayanan
N1 - Funding Information:
The authors sincerely acknowledge support from National Science Foundation (CMMI: 1727445) towards the conduct of this study. The contents of this paper reflect the views of the authors who are responsible for the facts and accuracy of the data presented herein, and do not necessarily reflect the views and policies of NSF, nor do the contents constitute a standard, specification or a regulation. We gratefully acknowledge the use of facilities within Laboratory for the Science of Sustainable Infrastructural Materials (LS-SIM) at Arizona State University.
Publisher Copyright:
© 2019
PY - 2019/4/5
Y1 - 2019/4/5
N2 - Material design of alkali activated fly ash-based binders for extrusion-based 3D printing, the rheological responses that are influential in ensuring printability, and the properties of such binders are discussed in this paper. Fly ash is supplemented with fine limestone, slag, or portland cement to provide adequate microstructural packing required for printability. The alkaline activators help reduce the yield stress and enhance the cohesiveness of the mixtures. Based on the measured shear yield stress at different times and concurrent printing of a filament, the printability window and yield stress bounds for printability, applicable for the chosen printing parameters, are established. This approach could be used for mixture qualification for extrusion-based printing. The Benbow-Bridgwater model is implemented on extrusion rheology results of pastes to determine the extrusion yield stress and wall slip shear stress, which are useful process-related parameters. It is shown that these parameters can also be related to shear and extensional rheological properties of alkali-activated pastes, thus ensuring a much-needed link between parameters related to material design and the process of extrusion. Mechanical properties and pore structure similar to those of conventionally cast mixtures are achieved.
AB - Material design of alkali activated fly ash-based binders for extrusion-based 3D printing, the rheological responses that are influential in ensuring printability, and the properties of such binders are discussed in this paper. Fly ash is supplemented with fine limestone, slag, or portland cement to provide adequate microstructural packing required for printability. The alkaline activators help reduce the yield stress and enhance the cohesiveness of the mixtures. Based on the measured shear yield stress at different times and concurrent printing of a filament, the printability window and yield stress bounds for printability, applicable for the chosen printing parameters, are established. This approach could be used for mixture qualification for extrusion-based printing. The Benbow-Bridgwater model is implemented on extrusion rheology results of pastes to determine the extrusion yield stress and wall slip shear stress, which are useful process-related parameters. It is shown that these parameters can also be related to shear and extensional rheological properties of alkali-activated pastes, thus ensuring a much-needed link between parameters related to material design and the process of extrusion. Mechanical properties and pore structure similar to those of conventionally cast mixtures are achieved.
KW - 3D printing
KW - Alkali activation
KW - Extrusion rheology
KW - Fly ash
KW - Yield stress
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U2 - 10.1016/j.matdes.2019.107634
DO - 10.1016/j.matdes.2019.107634
M3 - Article
AN - SCOPUS:85061185109
SN - 0261-3069
VL - 167
JO - International Journal of Materials in Engineering Applications
JF - International Journal of Materials in Engineering Applications
M1 - 107634
ER -