| 摘要 |
Cured cement matrices are exposed to dense-phase or supercritical CO2 which enters the matrix through passages therein to neutralize the natural alkalinity of the cement so that alkali-intolerant materials can be incorporated in the cement. The CO2 converts calcium hydroxide in the cement to calcium carbonate and water, and the high pressure of the dense-phase or supercritical CO2 forms rounded, closely packed and aligned crystals with few or no visible pores or capillaries to enhance the homogeneity and strength of the cured cement and its bonding with, for example, uncoated reinforcing glass fibers. The supercritical CO2 can be used to transport other organic or inorganic materials, including pulverized metal, in solution or suspension into the interior of the cement matrix to alter its chemical and/or physical characteristics. The supercritical CO2 can further be used to quickly determine if a particular cement specimen comes from a wet cement mix to which a material has been added which prevents or hinders cement carbonation. |
