Hardened hydraulic cement, ceramic or coarse concrete aggregate treated with high pressure fluids

Abstract

The properties of cement matrices are improved by one or more of the three processes which can be performed individually, sequentially, or in any desired combination. In each instance a supercritical fluid including at least one substance other than CO.sub.2 is flowed through the matrix and the matrix is contacted by the substance to change, e.g. react, constituents of the two with each other. Alternatively, the supercritical fluid can be used as a solvent, itself or by combining it with a solvent which itself may or may not be supercritical, and the fluid is infused into the matrix to carry into the matrix and there deposit the dissolved material. This step can be repeated with another supercritical fluid which has a reactant for the material dissolved so that, upon the infusion of the second supercritical fluid, the initially deposited material and the reactant react to provide the matrix with desired characteristics. In a third alternative the supercritical material includes a solvent which itself may or may not be supercritical and which, upon infusion into the matrix passages, dissolves a selected material which can then be flowed out of the matrix.

Dependencies are inferred from the claim text.