The Influence of Viscosity-Modifying Agent and Calcium-Carbonate on 3D Printing Mortar Characteristics (2023-06)¶

3D printing or additive manufacturing is an example of technology development in the construction sector. In 3D printing mortar, many things need to be considered regarding the characteristics of the mortar, such as workability, initial setting time, compressive strength, extrudability, and buildability. In previous studies, there were problems in the printing process, such as a lousy extrusion process and cracks in the 3D printing mortar sample. This study used calcium carbonate and a viscosity-modifying agent (VMA) to modify the mixture to achieve the desired characteristics. The extrudability and buildability were tested by observing the extrusion process and measuring the thickness and width of each layer printed. Based on the research, adding calcium carbonate and VMA can reduce workability and accelerate the initial setting time of the mixture. The use of VMA can reduce the compressive strength of the mixture. Using calcium carbonate and VMA can also increase the buildability of the mixture. From the compressive strength test, there was a decrease of 39.26% in the 3D printing mortar sample compared to the mortar cube sample. In addition, it was found that the 3D printing mortar is anisotropic, so the compressive force's direction affects the compressive strength produced.