Recycled Ceramic-Brick-Powder Utilization in Fiber-Reinforced 3D Printing Concrete (2024-11)¶

The incorporation of recycled ceramic brick powder (RCBP) into conventional cast concrete has proofed its efficacy in substituting aggregates, improving strength, and contributing to environmental sustainability. Concurrently, 3D printing technology is emerging as a pivotal trend in intelligent construction. This study investigates the collaborative interaction mechanisms of 3D-printed RCBP concrete. Compressive and four-point bending tests along the x, y, and z-axis are conducted to evaluate its strength and anisotropy. Subsequently, the hydration products and pore structural characteristics were analyzed employing Scanning Electron Microscope (SEM) and X-CT experiments. Additionally, an environmental life cycle analysis is performed utilizing OpenLCA software. The results determined an optimal RCBP content of 25-wt% yields satisfactory performance in macro-mechanical properties (with maximal 65.57MPa for compressive strength and 12.66 MPa for flexural strength) and micro-structural characterization. Specifically, the drainage consolidation effect achieved through 3D printing technology mitigates the typical decline observed in conventional RCBP concrete. However, exceeding the 25-wt% threshold leads to a noticeable decline in mechanical strength due to inhomogeneous particle gradation and excessive aggregation of RCBP particles, despite a significant reduction in porosity. Furthermore, as RCBP incorporation increases from 0-wt% to 100-wt%, four environment impact indicators including Global warming potential (GWP), Acidification Potential (AP), Ozone Depletion Potential (ODP), and Abiotic depletion potential (ADP) respectively decline by 24.86%, 6.59%, 0.49%, and 0.62%, demonstrating exceptional environmental benefits. Notably, the tremendous influence on GWP is attributed to the remarkable carbon sequestration of RCBP, aligning with national carbon neutrality goals and advancing sustainable construction practices.