3D Concrete Printing of Triply Periodic Minimum Surfaces for Enhanced Carbon Capture and Storage

Abstract

Concrete, the world's second most utilized material after water, is responsible for 8% of global greenhouse emissions. Current carbon capturing and storage (CCS) concrete often involves convoluted processes, slow kinetics, limited CO₂ uptake, non-uniform carbonation in structures, and high cost. Efforts to enhance carbon sequestration often rely on increasing porosities, which compromise the mechanical strength of the resulting concrete. The 3D printing of CCS concrete is reported by incorporating diatomaceous earth (DE), a highly accessible biomineral with hierarchical porosity, into triply periodic minimal surface (TPMS) structures. DE enables stable extrusion, high print fidelity, and reduced density, which are crucial for 3D concrete printing. Further, DE facilitates CaCO₃ nucleation within the concrete and mitigates carbonation resistance, achieving a maximum CO₂ absorption of 488.7 gCO₂ per kg cement in 7 days, a 142% increase over conventional concrete. Optimizing TPMS geometry further enhances carbonation efficiency by enabling uniform CO₂ uptake throughout the structure. This geometry refinement reduces material usage by 78% and increases the surface-area-to-volume ratio by 515%, leading to a 30% higher CO₂ uptake while preserving mechanical integrity. The material strategy, together with the optimized concrete printing of TPMS structures, offers a pathway toward scalable and sustainable solutions without undermining concrete's structural functions.