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

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. (C) 2018 Published by Elsevier Ltd.