Author
Aydın, Eylül Mina, Kara, Ahmet Burhan, Bundur, Zeynep Başaran, Özyurt, N., Bebek, Özkan, Gulgun, M. A.
Publication Date
2022-10-03
Publication Place
-
Elsevier
Subject
Mineral additives, Rheology, Sepiolite, Thixotropy, Three-dimensional (3D) printing
Type
Periodical
Language
English
Digital
Yes
Manuscript
No
Library
Özyeğin University
Library Asset ID
0950-0618
Record ID
5425452a-655e-47c0-a6dc-b3a41e62ea6b
Library Location
Civil Engineering, Mechanical Engineering
Date
2022-10-03
Notes
TÜBİTAK
Sample Text
Through the last decade, methods of digital manufacturing of concrete gained a significant interest compared to conventional concrete. The main challenge in additive manufacturing (3D printing) is to design a highly thixotropic cementitious system. This study aims to investigate the use of sepiolite as a rheology modifier as a novel approach to improve the thixotropic behavior and adapt cementitious systems to 3D printing. To understand the influence of sepiolite on rheological properties, a comparative evaluation with nano-montmorillonite was established. The effectiveness of clay addition was also investigated in fly-ash amended cement-based materials. The rheological analysis was done on cement-paste samples containing both clays in terms of their effects on thixotropy, structural build-up, and recovery. A preliminary printability assessment was done with a lab scale printer having a ram extruder. The results show that the incorporation of clays increased the dynamic yield stress and time-dependent evolution of static yield stress. Moreover, the addition of clays improved the thixotropic behavior of cement-based systems, particularly those containing fly-ash. Herein, the sepiolite was found to be more effective compared to nano-montmorillonite in terms of improving thixotropy, structural build-up and recovery. The results showed that use of fly-ash enhances the printability of the mix for the specified extruder and the samples containing 1% nano-montmorillonite or 0.5% sepiolite can be printed. The positive effects of sepiolite were attributed to opposing surface charges of the clay layers and its micro-fibrous microstructure. The findings in this study enabled an in-depth understanding of the rheology and printability of fly-ash amended clay containing printable cement-based mortars.
DOI
10.1016/j.conbuildmat.2022.128935
Cilt
350
