Mechanical properties and microstructure of oil well cement stone enhanced with Tetra-needle like ZnO whiskers

To fully utilize the Tetra-needle like ZnO whiskers (T-ZnO whiskers) and improve the mechanical properties of oil well cement, the cement composites with different addition of T-ZnO-w were prepared, and also analyzed by means of scanning electron microscopy (SEM), mechanical testing, X-ray diffraction (XRD), Infrared spectrum analysis, Thermal stability analysis and 29Si NMR analysis. The compressive, tensile and flexural strength has been increased by 8.96%, 137.44% and 27.96% respectively with the addition of 2% T-ZnO whisker, which demonstrated that the T-ZnO-w could reinforce the mechanical properties of oil well cement by the hydration product as dendritic crystals, resulting in the decrease of permeability and porosity. A new hydration named CaZn2(OH)6·2H2O generated during hydration process, and brittle phase Ca(OH)2 consumed during the hydration. Moreover, 29Si NMR analysis indicates that zincate whiskers can affect the chemical environment of Si element and structure of tobermorite chains. Thus, the current paper has some meaning to promote the study on solving the brittleness of oil-well cement.