Characteristics of the Porous Structure of Cement Stone

The complex study of filtration and electric properties of the samples of cement stone with different water-cement ratios is performed. It is established that filtration coefficient decreases by 4–6 times with an increase in a pressure drop and becomes constant at pressure drops above 3–3.5 MPa. The observed effect is interpreted as a reversible change in the internal structure of cement stone upon the filtration of a liquid through the stone. It is revealed that the filtration coefficient and porosity of samples decrease with time. Total open porosity and the most probable pore radius are determined by mercury porosity technique. Coefficients of structural resistance and pore tortuosity of the samples are determined from the comparison of through and total porosity. The values of streaming potential are measured and values of surface charge and potential of the samples of cement stone are calculated.