普通硅酸盐水泥基3D打印砂浆的性能及应用(英文)

Performance and Application of Ordinary Portland Cement-based Mortar for 3D Printing

以普通硅酸盐水泥(OPC)为胶凝材料制备具有快硬早强性能的3D打印砂浆。研究了OPC-3D打印砂浆的工作性、力学性能、层间粘结强度和收缩性能。结果表明:制备的OPC-3D打印砂浆初始状态的贯入强度约为0.05MPa,在35min时它的贯入强度达到0.7 MPa,之后强度快速增长。减水剂和触变剂能够使OPC-3D打印砂浆具有适合于3D打印施工的工作性,3D打印试件的28 d抗压强度能达到C40;3D打印的砂浆试件的抗压强度和钢筋握裹强度比标准模具成型的试件强度分别降低了10.65%和8.84%;3D打印试件的层间粘结强度为2.53 MPa;硫铝酸盐水泥早强组分水化生成钙矾石不仅促进了OPC-3D打印砂浆凝结,而且使其在标准养护条件下具有一定微膨胀性能。并利用普通硅酸盐水泥3D打印砂浆打印了小型房屋和构件。

Ordinary Portland cement(OPC) can be used as an excellent cementitious material for manufacturing architectural components by 3D mortar printing due to its superior properties(i.e., rapid hardening and high early strength). In this work, OPC-based mortar was prepared for 3D printing. The fluidity, thixotropic property and mechanical properties of mortar were investigated. The experimental results show that the penetration strength of fresh mortar is 0.05 MPa, and the penetration strength can rapidly increase to 0.7 MPa within 35 min. Besides, the 28-d compressive strength of 3D printed specimens using OPC-based mortar for 3D printing can reach C40 level. Compared to the standard mold-casting specimens, the 3D printed specimens have lower compressive strength and inter-layer bond strength, which are decreased by 10.65% and 8.84%, respectively. The inter-layer bond strength of the printed specimen is 2.53 MPa. The ettringite produced due to the hydration of sulphoaluminate cement promotes the condensation of OPC-3D printed mortar and makes OPC-3D mortar have a certain micro-expansion performance under standard curing conditions. Meanwhile, small houses and building components could be printed via the 3D mortar printing process.