Application of electro-injection method in improving cement mortar durability

An electrochemical method for improving durability of cement mortar by injection of nanoparticle (Al2O3 coated SiO2) is presented. In this method, nanoparticles are injected into cement mortar pores under an external electrical field, refining pore structure of cement mortar. The efficiency of electro-injection nano-particle treatment with different applied electric fields was evaluated by monitoring the evolution of cement mortar resistivity. The improvement of cement mortar durability after electro-injection of nano-particle treatment was assessed by examining the resistance to water absorption, carbonation, sulfate resistance and chloride diffusion. The microstructure of cement mortar after the electro-injection treatment was analyzed using Scanning Electron Microscope (SEM), Mercury Intrusion Porosimetry (MIP), X-Ray Diffraction (XRD) and Differential Thermo-Gravimetric Analysis (DTG). The results show that improving cement mortar durability by the injection of nanoparticle under external electric field can be obtained. The efficiency of electro-injection nano-particle treatment increased with the increasing of applied electric field. The resistance to water absorption, carbonation, sulfate attack and chloride diffusion were significantly improved by using the electro-injection method. The improvement in cement mortar durability can be attributed to the filling effect of nanoparticles.