Rheological and harden properties of the high-thixotropy 3D printing concrete

• Published in: Construction & building materials 2019-03, Vol.201, p.278-285
• Main Authors: Zhang, Yu, Zhang, Yunsheng, She, Wei, Yang, Lin, Liu, Guojian, Yang, Yonggan
• Format: Article
• Language: English
• Subjects: 3D printing; 3D printing concrete; Analysis; Anisotropy; Concretes; Construction industry; Harden property; Mechanical properties; Technology; Thixotropy
• ISSN: 0950-0618; 1879-0526
• DOI: 10.1016/j.conbuildmat.2018.12.061

•A high-thixotropy 3D printing concrete has been successfully developed.•Such concrete had lower drying shrinkage, normal elastic modulus and Poisson’s ratio.•The rheological properties and anisotropy of such concrete were systematically investigated.•A series of large-scale components industry–scale were applied into public transportation. 3D printing is a promising technology in construction industry. Unlike conventional construction process, 3D printing buildings are extruded by a nozzle layer-over-layer without the requirement of formwork. This paper investigates the rheological and harden properties of the high-thixotropy 3D printing concrete. Flowability, rheological property (viscosity, yield stress, thixotropy) and open time are considered as critical wet properties to control the printable property (pumpability, extrudability and buildability) of such concrete material. Five different mixtures are systematically investigated to obtain the optimum mix and then it’s used to study the harden property, such as anisotropy (compression and flexural), elastic modulus and drying shrinkage. At last, a large-scale components-bus station preliminarily was prepared by using this technology.