3D 打印再 生粗骨料混凝 土抗冻性能试验研究.

3D printing technology has been significantly developed in the construction field, and in order to address the concrete 3D printing industry to achieve sustainable development, this paper analyzes the causes of deterioration by conducting freezing resistance studies on 3D printed specimens and cast specimens with 0%, 50%, and 100% recycled coarse aggregate（RCA） substitution, combined with electron microscopy scans of the transition zone at the interface of 3D printed recycled coarse aggregate concrete（3DPRAC）. The results showed that the incorporation of RCA in the first 200 freeze-thaw cycles did not significantly reduce the mass and dynamic modulus of 3D printed concrete; after 600 freeze-thaw cycles the 3D printed recycled concrete with 100% RCA incorporation performed better than that with 50% RCA incorporation in the freeze-thaw cycles. Based on the construction characteristics of 3D printed recycled concrete stacked layer by layer, a 3DPRAC pore area concentration distribution model was proposed to reveal the 3DPRAC freeze-thaw damage deterioration mechanism. The established freeze-thaw damage model can better reflect the change pattern of 3DPRAC freeze-resistance performance. [ABSTRACT FROM AUTHOR]