原位涂层钢筋增强3D打印混凝土握裹力

Bond Behavior of In-Situ Coated Rebars in 3D Printed Concrete

摘要:

为解决直接插入钢筋增强3D打印混凝土技术中的空隙问题，提出了原位涂层技术.分别使用自密实砂浆与超细灌浆水泥作为原位涂层材料，制备了原位涂层钢筋增强3D打印混凝土，研究了钢筋在混凝土中的拉拔性能.结果表明：使用水泥基材料对钢筋进行原位涂层，可以得到密实的钢筋-混凝土界面，与直接插入技术相比，拉拔强度得到了最大345.0%的提升；钢筋拉拔曲线符合常规的四段式.这证明使用水泥基材料的原位涂层技术可以实际应用于3D打印混凝土的加筋工艺中，并有效提升3D打印混凝土结构的力学性能及耐久性能，为混凝土3D打印技术的工程应用提供了创新方法及理论基础.

Abstract:

To address the gap issue between the directly-inserted rebars and printed concrete， an in-situ technique was proposed to coat the inserted rebars to diminish the voids and enhance the bonding performance. The self-compact mortar and ultra-fine grouting cement were separately used as the in-situ coating materials to prepare in-situ coated rebar-reinforced 3D printed concrete. Experimental results shows that dense contact was established between the rebar and the composite， and the bonding strengths were maximally improved by 345.0% higher than that of the direct-inserted rebars. The bond-slip behavior of the steel bar conforms to the conventional four-segment curve pattern. These findings indicate that the cement-based in-situ coating technique is highly effective for reinforcing 3D printed concrete， significantly enhancing its mechanical properties and long-term durability. This innovative approach provides both a practical solution and a theoretical foundation for the engineering application of concrete 3D printing technology.