Complex Geometry Forms and Curved Surfaces in 3D Concrete Printing

Problem statement: 

One of the most critical issues in architectural design is form, which has become more complicated in computational design. To overcome such problems nowadays, digital manufacturing methods such as additive manufacturing could be used. For a long time, concrete has been considered one of the primary materials in architecture. In recent decades, concrete 3D printing has made significant progress and practical samples such as pedestrian bridges, residential units, and urban furniture have been made with this technology. One of the most important advantages of 3D printing is the creation of complex geometries including curved surfaces. In 3D concrete printing, due to its large scale, some defects of the printed surfaces, such as the staircase effect are more visible. One of the methods that could be used to make the final finish of the printed surface smoother and closer to the original digital design is the application of curved (non-flat) layering in the production process. This method could produce surfaces with a better finish only by intervening at the software level and using the existing hardware.

This paper seeks to investigate the methods presented in the additive manufacturing of cementitious materials and attempts to find their advantages and limitations in published articles.

In this review article, the documentary data collected from published scientific documents like articles, books, and theses, have been analyzed using a descriptive-analytical method.

Three main methods in additive manufacturing of concrete materials have been investigated, and the advantages and limitations of each have been listed. The main challenges for additive manufacturing of concrete in the three categories: properties of printable concrete, supporting structures for concrete printing, and the presence of cold joints were investigated, and finally, the methods presented for the construction of curved surfaces with 3D concrete printing technology were mentioned.