碳化钢渣粉对3D打印水泥基材料工作性能及力学性能的影响

Effects of Carbonated Steel Slag Powder on Workability and Mechanical Properties of 3D-Printed Cement-Based Materials

摘要:

为有效降低钢渣中游离CaO含量以减小后期膨胀开裂风险，对钢渣粉（SS）进行碳化处理，并将其用于制备3D打印水泥基材料。通过对比分析碳化前后SS的物化特性，探究其对3D打印水泥基材料流变性能、可打印性及力学性能的影响规律。结果表明：碳化钢渣粉（CSS）的主要产物为CaCO₃，表面粗糙度增加、比表面积增大；与掺未碳化钢渣粉（RSS）试样相比，掺CSS试样静、动态屈服应力分别提高61.70%和61.68%，可打印性显著改善；当SS掺量为30%时，掺CSS试样7、28 d抗压强度较掺RSS试样分别提高20.28%和2.42%。微观结构表明，CSS能够促进CaCO₃、钙钒石（AFt）及水化硅酸钙（C-S-H）凝胶生成，形成密实交织结构，从而提升3D打印水泥基材料的力学性能。

Abstract:

To effectively reduce the content of free CaO in steel slag and minimize the risk of late-stage expansion and cracking， carbonization treatment was carried out on steel slag powder（SS）， and it was then used to prepare 3D-printed cement-based materials. By comparatively analyzing the physicochemical properties of SS before and after carbonization， the influence patterns on the rheological properties， printability， and mechanical properties of 3D-printed cement-based materials were explored. The results show that the main product of carbonated steel slag powder （CSS） is CaCO₃ with the increased surface roughness and specific surface area. Compared with samples incorporating uncarbonized steel slag powder （RSS）， those with CSS exhibits 61.70% and 61.68% increase in both static and dynamic yield stresses， along with significantly improved printability. When the steel slag powder content is 30%， the compressive strengths of the CSS group at 7， 28 d can be increased by 20.28% and 2.42%， respectively， compared to those of the RSS group. The microstructure reveals that CSS promotes the generation of CaCO₃， ettringite （AFt）， and calcium silicate hydrate （C-S-H） gel， forming a denser interwoven structure and thus enhancing mechanical properties.