ANALYSIS OF THE PHYSIOMECHANICAL PROPERTIES OF PORTLAND CEMENT BASED ON THE PARTICLE SIZE DISTRIBUTION AND CHEMICAL OXIDE COMPOSITION

The physiomechanical properties of Portland cement mortar paste was studied based on the particle size distribution and the chemical oxide composition using standard experimental procedures. The X-ray florescence (XRF) was used to determine the composition of the chemical oxides. The cement particle sizes of 45, 63, 90, 180 and 212µm were used to produce cement paste and mortar with water-cement ratio of 1:2 and cement-sand ratio of 1:3. The cement paste was subjected to test to determine the setting times and soundness values. The cement mortar was used to produce cement cubic blocks of 40 x 40 x 160mm size which were tested for compressive strength at various aging times of 2, 7 and 28 days. Results obtained showed that the predominant oxides were CaO, SiO2, Al2O3 and FeO3 which were at the respective percentage compositions of 60.0, 20.6, 5.5, and 3.84%. Other alkali oxides such as K2O, NaO and MgO were obtained in trace quantities. These values compare well with standard values for Portland cement composition. It was found that particle size distribution and chemical oxide composition have significant effect on setting times and compressive strength. However, soundness was found to be dependent on the chemical oxide composition of the cement. It was therefore concluded that the non-linear relationship obtained between the particle size and the compressive strength shows that the property is function of other multiple factors such as chemical oxide composition, like burning condition or cooling rate affect the strength of cement mortar.