Insights into material design, extrusion rheology, and properties of 3D-printable alkali-activated fly ash-based binders
Insights into material design, extrusion rheology, and properties of 3D-printable alkali-activated fly ash-based binders
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DOI：
10.1016/j.matdes.2019.107634
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发表时间：
2019-04-05
影响因子：
8.4
通讯作者：
Neithalath, Narayanan
中科院分区：
文献类型：
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作者：
Alghamdi, Hussam;Nair, Sooraj A. O.;Neithalath, Narayanan
本文讨论了用于基于挤出的3D打印的碱活化粉煤灰基粘合剂的材料设计、对确保可打印性有影响的流变反应以及此类粘合剂的性能。粉煤灰补充细石灰石，矿渣，或波特兰水泥，以提供适当的微观结构包装所需的印刷性。碱性激发剂有助于降低屈服应力并增强混合物的粘结性。基于在不同时间测量的剪切屈服应力和长丝的同时印刷，建立适用于所选印刷参数的可印刷性窗口和可印刷性的屈服应力界限。该方法可用于基于挤出的印刷的混合物鉴定。本鲍-布里奇沃特模型的糊料的挤出流变学结果，以确定挤出屈服应力和壁滑移剪切应力，这是有用的工艺相关参数。结果表明，这些参数也可以与剪切和拉伸流变性能的碱激活的膏体，从而确保了急需的链接相关的材料设计和挤出过程中的参数之间。机械性能和孔隙结构类似的常规铸造混合物实现。(C)2019由Elsevier Ltd.出版
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. (C) 2019 Published by Elsevier Ltd.