摘要 |
Methods for forming very early setting, ultra high strength cements and the cements so produced are claimed. The methods comprise forming a mixture of raw materials containing SiO2, Al2O3, CaO, Fe2O3, and SO3, respectively designated S, A, C, F, and &upbar& S such that the overall molar ratio of A/F exceeds approximately 0.64 and the overall molar ratio of &upbar& S/A+F is between approximately 0.35 and 0.25. This mixture is heated to n elevated temperature between 1,000 DEG C. and 1,200 DEG C. for a sufficient period of time to produce a clinker containing high concentrations of C4A3 &upbar& S. The average amount of C4A3 &upbar& S is then determined and a final mixture is formed utilizing the high C4A3 &upbar& S clinker, C containing hydraulic or portland type cement and soluble C &upbar& S anhydride to produce a final cement mixture having a C4A3 &upbar& S content of approximately 10% to 30% by weight, a soluble C &upbar& S anhydride content of approximately 5% to 20% by weight, and the remainder being hydraulic or portland type cement. The cements so produced exhibit very early, ultra high strength ranging from 3,000 psi to 5,000 psi in one hour, 6,000 psi in one day, and 11,000 psi in 28 days.
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