3D printed concrete walls reinforced with flexible FRP textile: Automatic construction, digital rebuilding, and seismic performance

As numerous impressive large-scale 3D printed concrete structures have been built with 3D concrete printing (3DCP) technology, more attention has been given to the automation, accuracy and reliability of this technology. The concept of Brain-Eyes-Hands Loop (BEH Loop) is defined for use in automatic construction, describing the relationships among design, evaluation, and construction. In this paper, an innovative continuous reinforcement method with fiber reinforced polymer (FRP) flexible textile and Engineered Cementitious Composite (ECC) is presented, that offers an effective solution for the lack of tensile reinforcement and corrosion of steel bars in 3D printed concrete structures. The reinforced 3D printed concrete walls were constructed, evaluated, and tested under quasi-static cyclic loading. By digital rebuilding and geometric evaluation, the printing quality of wall specimens was accessed and ensured. Based on the mechanical tests, the seismic performances of the wall specimens were obtained and found to be mainly bending failure. The proposed reinforcement method was demonstrated for delaying crushing and improving mechanical behaviors. The end column and smaller height-width ratio also showed much improvement in mechanical performance. Compared with the conventional cast concrete wall, the 3DCP wall specimens reinforced by the proposed reinforcement method showed better material utilization efficiency and mechanical properties. Therefore, the 3DCP structures reinforced with flexible FRP textile show great potential for the future use in fully automatic construction of large-scale complex architectures according to the frame of the BEH Loop.