Effects of chemical admixture on rheological properties of 3D printing building mortar.

The effects of superplasticizer agent and retarder on the apparent viscosity, thixotropy and rheological properties of 3D printing building mortars at different shear rates were investigated. The results show that when the amount of superplasticizer agent is increased, the apparent viscosity is almost unchanged, the thixotropy will first decrease and then tend to be unchanged, the plastic viscosity will decrease first and then increase, and the yield stress will gradually decrease; the retarder will increase the apparent viscosity of the 3D printing building mortar and increase the yield stress of the slurry. When the amount is higher, the thixotropy of the mortar will increase. The rheological properties of 3D printing mortar can be improved by adding appropriate superplasticizer and retarder, which can meet the printing requirements. [ABSTRACT FROM AUTHOR]