Optimizing the Application of Recycled Dust Powder in 3d Concrete Printing Materials Through Particle Densely Packing Theory

Abstract

To reduce the cost of printing material and promote the application of digital construction, recycled dust powder (RDP) is utilized to replace cementitious material in printing materials production. Considering the defect of low-reactivity and inferior property of RDP, the modified Andreasen and Andersen model is utilized to design the printing material. It is found that the addition of RDP would optimize the particle gradation of the material, and replacing cementitious material with RDP can improve the buildability of the printing material. Influence of RDP on the yield stress and viscosity of different mixtures are investigated by rheological experiment. Mechanical strength, isothermal calorimetry and mercury intrusion porosimetry tests are also used as criteria to measure the printing performance of the printing material. The rheological results manifest that the addition of 10\% RDP would increase the yield stress and maintain the viscosity of the printing material. Moreover, through particle size design, the addition of RDP reduces the macropore(>1000nm) from 10.7\% to 7.1\%, thus keeping the compressive strength within an acceptable range. Finally, the results of laboratory printing or industrial printing also confirm the printing performance of printing material.

Keywords: Recycled dust powder, Modified Andreasen and Andersen model, recycled construction aggregate, 3D concrete printing, Gradation optimization