Karlsruher Institut Fur Technologie

Forschungszentrum Karlsruhe Gmbh

Guenter Beuchle

Peter Stemmermann

Uwe Schweike

Krassimir Garbev

Hans Hunsinger

Karolina Giziewicz

A process for preparing dicalcium silicate includes providing a starting material comprising calcium carbonate (CaCO) and silicon dioxide (SiO), wherein a molar ratio of calcium:silicon (C:S) is from 1.5:1 to 2.5:1. At least one of an inorganic alkali metal salt and an alkaline earth metal salt is added as a mineralizing agent to the starting material in an amount of from 0.5 wt.-% to 20 wt.-%, based on a total weight of the starting material. The starting material is reacted with the mineralizing agent in a gas atmosphere having a COpartial pressure of from 0.05 MPa to 0.2 MPa at a temperature of from 900&#xb0; C. to 1100&#xb0; C. so as to obtain a dicalcium silicate product. The dicalcium silicate product comprises a content of an unreacted starting material of &#x3c;5 wt.-% and a total carbon content of &#x3c;1.5 wt.-%, each based on a weight of the dicalcium silicate product.

Method for producing dicalcium silicate

The invention relates to a monophase amorphous hydraulic binder containing silicon, calcium and oxygen atoms in an arrangement comprising silicate building units having an average connectedness of at least Q, with none or a part of the calcium atoms being substituted for by a metal atom M[6]sixfold or higher-coordinated with oxygen and/or none or no more than 45 atomic percent of the silicon atoms being substituted for by a metal atom M[4]tetrahedrally coordinated with oxygen, the molar ratio of[CaO+(/2)&#xb7;(M[6]O)]:[SiO+M[4]O]having a value of 0.2 to 1.5, and the binder having less than 3.5% by weight of water, as well as a mixture containing this binder. Furthermore, the invention relates to methods for manufacturing the binder or a mixture containing this binder by reaction grinding a starting material containing silicate building units having a connectedness of Qto Q, with a solid silicate raw material having a connectedness of the silicate building units of Qto Qand optionally drying the monophase hydraulic binder to a water content of below 3.5% by weight. Finally, the invention relates to a building material made by setting the binder or a mixture containing this binder with water and subsequent hardening.

Single-phase hydraulic binder, methods for the production thereof and building material produced therewith

The invention relates to a monophase hydraulic binder containing silicon, calcium, oxygen and hydrogen atoms in an arrangement comprising silicate building units having an average connectedness of no more than Qand silanol groups, with none or a part of the calcium atoms being substituted for by a metal atom M[6]sixfold or higher-coordinated with oxygen and/or none or a part of the silicon atoms being substituted for by a metal atom M[4]tetrahedrally coordinated with oxygen, the molar ratio of[CaO+(x/2)&#xb7;(M[6]O)]:[SiO+M[4]O]having a value of 0.75 to 2.75, and the binder containing an HO content of 3.5% by weight to 20% by weight, as well as a mixture containing this binder. Furthermore, the invention relates to methods for manufacturing the binder or a mixture containing this binder by converting calcium-containing and silicate-containing starting materials into a preproduct which at least in part contains a calcium hydroxosilicate, subsequent grinding of the calcium hydroxosilicate until the monophase hydraulic binder forms, and optionally drying the monophase hydraulic binder to an HO content of 3.5% by weight to 20% by weight. Finally, the invention relates to a building material made by setting the binder or a mixture containing this binder with water and subsequent hardening.

Single-phase hydraulic binder, methods for the production thereof and structural material produced therewith

The invention relates to a monophase hydraulic binder containing silicon, calcium, oxygen and hydrogen atoms in an arrangement comprising silicate building units having an average connectedness of higher than Qand silanol groups, with none or a part of the calcium atoms being substituted for by a metal atom M[6]sixfold or higher-coordinated with oxygen and/or none or a part of the silicon atoms being substituted for by a metal atom M[4]tetrahedrally coordinated with oxygen, the molar ratio of[CaO+(/2)&#xb7;(M[6]O)]: [SiO+M[4]O]having a value of 0.2 to 2.0, and the binder having an HO content of 3.5% by weight to 20% by weight, as well as a mixture containing this binder. Furthermore, the invention relates to methods for manufacturing the binder or a mixture containing this binder by reaction grinding a starting material of silicate building units having a connectedness of Qto Q, and optionally further materials, with a solid silicate raw material having a ceonnectedness of the silicate building units of Qto Qand optionally drying the monophase hydraulic binder to an HO content of 3.5% by weight to 20% by weight. Finally, the invention relates to a building material made by setting the binder or a mixture containing this binder with water and subsequent hardening.

A method for producing components including preparing an aqueous suspension of solids including calcium oxide CaO and silicon dioxide SiO2 with a molar ratio of Ca:Si that is between 0.5:1.0 and 2.5:1.0. Nanocrystalline C&#x2014;S&#x2014;H phases are produced by grinding the aqueous suspension and keeping its temperature at or below 100&#xb0; C. The aqueous phase is separated out from the suspension to form a residue containing the nanocrystalline C&#x2014;S&#x2014;H phases. The residued is removed and a powdery product is made by drying the residue. A mold is filled with the powdery product and pressure is applied to form the component. The component is removed from the mold.

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Karlsruhe, Germany

Guenter Beuchle