Indirect sonication effect on the dispersion, reactivity, and microstructure of ordinary portland cement matrix

Abstract

Utilizing nanotechnology for the production of nano cement may be considered as an innovative potential approach that can be reached via increasing the specific surface area of cement. Van der Waals forces are the main reason behind the agglomeration of cement particles in concrete. The balance between repulsive and attractive forces of cement particles has a profound effect on concrete properties. The present study focuses on the effect of ultrasonic processing at relatively low frequency on the dispersion of cement particles and investigating the effectiveness of such approach in increasing the sub-nano metric cement content leading to increasing cement reactivity. A qualitative analysis was conducted with a view to investigate the sonication effect on the mechanical properties of cement. In addition micro-structural analyses were conducted to understand the surface morphology and microstructure of cement composites using particle size distribution, scanning electron microscope, Thermo-gravimetric analysis, X-ray diffraction and atomic force microscopy tests. The results of the investigational study showed that the mechanical, and microstructure of cement pastes can be remarkably improved by subjecting the cement slurry to an optimum time of sonication. The proposed method helped in achieving specific surface area of 138900 m2/kg with sub-nano metric cement particles of 80% and gain in compressive strength of about 27%. The microstructural analysis performed revealed that the proposed sonication method had influenced the micro structure of the cement matrix by increasing the reactivity of the cement particles as a result of their transfer to the nano level. Moreover, the microstructural analysis highly confirmed the determined mechanical properties.