Effect of potassium and sodium-based electrolyzed water on the rheological properties and structural build-up of 3D printed cement composites

The uncontrollable printability and structural integrity limit the development and application of 3D printed cement composites. In this study, the potassium and sodium-based electrolyzed water (KEW and NEW) were incorporated into the 3D printed ordinary Portland cement composites (OPCCs) to adjust rheological properties, aiming to improve printability and optimize the printed structure build-up. Experimental results show that the KEW can enhance the elastic modulus and decrease the strain notably as the applied shear stress increases. Compared with tap water (TW), the KEW and NEW increase the static yield stress based on oscillation-shear and creep-recovery protocol, and improve thixotropy. Besides, the structure deformation of 3D printed OPCCs with NEW and KEW decreases from 11.81 % to 8.34 % and 8.22 %, respectively, representing a margin of approximately 29.4 % and 30.4 %. Furthermore, the compressive and flexural strength of 3D printed OPCCs with KEW increases from 25.5 to 29.4 MPa and 3.55 to 4.04 MPa, respectively, benefitting from the lower porosity and higher hydration rate. In conclusion, the incorporation of electrolyzed water into 3D printed OPCCs demonstrates considerable potential, effectively enhancing printability and optimizing structure build-up.