Test methods for 3D printable concrete

3D concrete printing (3DCP) is a modern and upcoming technology that consists of building a structure layer by layer without the use of formwork. The quality of a 3D printed structure depends on various factors, predominantly 3D printable concrete (3DPC) mixes. As 3DCP development progresses from the laboratory to in-situ, understanding the fresh and hardened characteristics of 3DPC and the influencing factors are essential. This paper aims to give an up-to-date critical review of the various test methods used to characterize the fresh and hardened properties of 3DPC. The factors influencing the test techniques and future research directions for standardizing the test methods of 3DPC are discussed. The extensive information provided in this review on various test techniques used in 3DPC will assist the engineering community and 3DPC manufacturers in selecting the suitable methods or standards to test the 3DPC.