A Study on Influence of Zinc Oxide in Cement Composite Materials

In this research, the influence of zinc oxide (ZnO) on the phase compositions and crystalline structure and microstructure of cement composite was studied. ZnO powder (0.5-1 wt% of cement) was used as an additive material. The Portland cement and ZnO powder were blended and mixed with water at the ratio constant (W/C) of 0.4. Then, the paste was cast into the molded for 24 hours. After these periods, the samples were dried at temperature 50°C for 24 hours. Those of samples were analyzed of crystalline structure and phase compositions by using X-ray diffraction technique (XRD). Microstructure analysis by using field emission scanning electron microscopy (SEM). It was found that the XRD spectra showed phases of calcium hydroxide (CH) and calcium silicate hydrated (CS), which were hydration products of cementitious material. Moreover, phase of zinc hydroxide (Zn(OH)2) is detected. Zn(OH)2have affected on the retardation of hydration reaction (more than 48 h). Zn(OH)2phase was formed on the surface of anhydrous tricalcium silicate (C3S) main compound in cement. The intensity of un-hydration products (C3S and C2S) increased with increasing content of ZnO nanoparticle in cement composites.