TY - JOUR
T1 - Improving printability of limestone-calcined clay-based cementitious materials by using viscosity-modifying admixture
AU - Chen, Yu
AU - Figueiredo, Stefan Chaves
AU - Li, Zhenming
AU - Chang, Ze
AU - Jansen, Koen
AU - Çopuroğlu, Oğuzhan
AU - Schlangen, Erik
PY - 2020
Y1 - 2020
N2 - In 3D concrete printing (3DCP), it is necessary to meet contradicting rheological requirements: high fluidity during pumping and extrusion, and high stability and viscosity at rest to build the layered structure. In this paper, the impact of the hydroxypropyl methylcellulose (HPMC)-based viscosity-modifying admixture (VMA) on the 3D printability and mechanical performance of a limestone and calcined clay based cementitious material is investigated. A combination of VMA and superplasticizer was used for that purpose. In this case, controlling the competitive effects between VMA and superplasticizer becomes critical. The main strategy for 3D printing in this study was to add an optimal dosage of VMA in the solid suspension that was already mixed with water and superplasticizer. A lab-scale 3DCP setup was developed and demonstrated as well. A series of tests was performed to characterize the effects of VMA on flowability, extrudability, open time, buildability, green strength, hydration, compressive strength, and air void content and distribution. Experiments performed in this study showed that the mixture containing 0.24% (of the binder mass) of VMA exhibited satisfactory 3D printability and optimal mechanical performance. Finally, the results, limitations, and perspectives of the current research were discussed.
AB - In 3D concrete printing (3DCP), it is necessary to meet contradicting rheological requirements: high fluidity during pumping and extrusion, and high stability and viscosity at rest to build the layered structure. In this paper, the impact of the hydroxypropyl methylcellulose (HPMC)-based viscosity-modifying admixture (VMA) on the 3D printability and mechanical performance of a limestone and calcined clay based cementitious material is investigated. A combination of VMA and superplasticizer was used for that purpose. In this case, controlling the competitive effects between VMA and superplasticizer becomes critical. The main strategy for 3D printing in this study was to add an optimal dosage of VMA in the solid suspension that was already mixed with water and superplasticizer. A lab-scale 3DCP setup was developed and demonstrated as well. A series of tests was performed to characterize the effects of VMA on flowability, extrudability, open time, buildability, green strength, hydration, compressive strength, and air void content and distribution. Experiments performed in this study showed that the mixture containing 0.24% (of the binder mass) of VMA exhibited satisfactory 3D printability and optimal mechanical performance. Finally, the results, limitations, and perspectives of the current research were discussed.
KW - 3D concrete printing
KW - Limestone and calcined clay
KW - Mechanical performance
KW - Sustainability
KW - Viscosity-modifying admixture
UR - http://www.scopus.com/inward/record.url?scp=85081650799&partnerID=8YFLogxK
U2 - 10.1016/j.cemconres.2020.106040
DO - 10.1016/j.cemconres.2020.106040
M3 - Article
SN - 0008-8846
VL - 132
JO - Cement and Concrete Research
JF - Cement and Concrete Research
M1 - 106040
ER -