Influence of Phase-Change-Material on Concrete Behavior for Construction 3D Printing (2021-10)¶

Large-scale construction 3D printing (C3DP), which is also known as green building construction is an innovative method that can save time, materials, and labor costs. The suitable printing materials should have the properties of good fluidity, excellent early strength, appropriate setting time, suitable viscosity, and cost-effectiveness. Among the main concerns of the construction 3D printing, the clogging of the material induced by premature setting and poor fluidity of the concrete is a significant one. It hinders the pumping capacity of concrete materials from the mixer to the extruder and reduces the overall efficiency of the C3DP process. The existing literature has proposed a variety of materials for C3DP, but there is still no standard information on the material selection. Therefore, it is necessary to solve the problem of material clogging while obtaining the above-mentioned characteristics suitable for printing materials. In the present study, the suitable printing properties for C3DP material were obtained to solve the clogging problem. The composition based on industrial solid waste was used to prepare this material. The use of this material in C3DP was proved to be cost-effective. Suitable setting time (33 min), good fluidity (181 mm), and excellent compressive strength (10.4 MPa and 78.2 MPa for 2 h and 28 days, respectively) were realized. These suitable properties were obtained by adding the phase change material (PCM) at different temperatures. In addition, due to the phase change characteristics, PCM has been proven to effectively solve the clogging problem of material. Furthermore, optimized material was used to print 3D structures with different shapes. We believe that this work can provide innovative ideas for the promotion of green building construction and the production of high-value products.