Optimization of self-healing additives dispersity in cement

Abstract

The article reflects results of the experimental studies on the modifying agent’s dispersion to affect the nature of its distribution in the total volume of cement stone. An attempt was made to evaluate the strength and filtration properties of the cement stone with respect to the heterogeneity of its structure. The effect of a character of the modifying additive distribution on the permeability and strength of the cement stone was investigated, as a result it was clarified that the zone of influence of the applied dynamic load does not depend on the heterogeneity of the plugging material, and the values ​​of deformation in the cement stone depend on the dispersion, the nature of the distribution of the additive in the volume of the cement stone, the period of the modifying agent activation. The dynamic loads, which most strongly provoke the destruction of cement stone under the influence of high stresses, are considered. Using the finite element method (FEM), the ANSYS application program evaluated stresses in a cemented column, describes the process of deformation of cement stone, taking into account the heterogeneity of its structure. Based on the variability of the additive location, channel models for the most preferred localization of the modifying additive have been determined as open through cracks. The application of the mathematical model, which was elaborated, demonstrates a possibility of the maximum reduction of the water conductivity if the optimal distribution of the modifying additive in the matrix of the cement stone provided.

Keywords

• modifying additive
• crack
• “self-healing” cement
• dynamic loads
• shear stresses
• cement stone bending strength