A novel approach of geopolymer formulation based on clay for additive manufacturing

This paper investigates the potential for combining robotic and additive manufacturing in construction with geopolymerization. 3D printing is considered an essential element of the new industrial revolution. As a technology that facilitates construction work and minimizes the production line. Geopolymers obtained by alkaline activation of aluminosilicate materials are considered ecological. These materials can help solve the CO2 emission problem and be an effective substitute for building materials due to their mechanical performance and significant durability properties. This study presents a new approach of geopolymer based on clay for 3D printing purpose. Four formulations based on a silicate and sodium hydroxide geopolymer binder were prepared. The silicate to sodium hydroxide ratio was 0.24 and the molarity of NaOH was 10 M. The ratio sand/clay was 1:1. The printability, extrudability and buildability of this new material have been studied. This geopolymer was printed using a robotic arm 3D printer based on the extrusion technique for formulation validation. Mechanical tests for compressive and flexural strength were carried out on the printed geopolymer. The results of this study demonstrate that clay-based geopolymer can replace cement mortar in the 3D printing process with interesting mechanical performance to meet the application requirements in the construction sector.