A study on the manufacturing of energetically-modified reject fly ash and the characteristics of mortar

Energetically-modified material using reject fly ash (RFA), generated from thermal power plants, was manufactured to investigate the effect of the material on the physical and chemical characteristics of cement mortar. In order to modify reject fly ash, a vibration mill was used. Particle size, grain shape, and crystal structure of the ash were analyzed. Then, the compressive strength of the mortar using energetically-modified reject fly ash (ERFA) was measured. Microstructure and X-ray diffraction (XRD) patterns were also used in the analysis. As the replacement rate of ERFA increased, the value of the compressive strength tended to decrease. However, it was found that the compressive strength values of 7 and 28 days-cured specimens were higher than those of conventional ordinary Portland cement (OPC) mortar with 10 % replacement rate condition.