Abstract: The claimed subject matter relates to a novel cement comprising Portland cement clinker and a supplementary cementitious material. The supplementary cementitious material comprises a heat treated clay material and an optionally heat treated carbonate material, wherein the clay material has been heat treated optionally together with the carbonate material in such a way that the heat treated clay material is substantially dehydroxylated while the optionally heat treated carbonate material remains substantially carbonated. This can be achieved by premixing the carbonate and clay materials before heat treating to 400-700 C, or heat treating the clay material separately to a temperature of up to 900 C. When used in the final application the cement results in much higher strengths than would be predict from any other combination of these materials.

Abstract: The claimed subject matter relates to a novel cement comprising Portland cement clinker and a supplementary cementitious material. The supplementary cementitious material comprises a heat treated clay material and an optionally heat treated carbonate material, wherein the clay material has been heat treated optionally together with the carbonate material in such a way that the heat treated clay material is substantially dehydroxylated while the optionally heat treated carbonate material remains substantially carbonated. This can be achieved by premixing the carbonate and clay materials before heat treating to 400-700 C, or heat treating the clay material separately to a temperature of up to 900 C. When used in the final application the cement results in much higher strengths than would be predict from any other combination of these materials.

Abstract: A shaped article, at least one domain of which has a three-dimensionally reinforced composite structure comprising of a matrix and a reinforcing system (2, 4, 5, 6), the reinforcing system comprising bodies such as bars, wires, cables, or plates embedded in the matrix and extending three-dimensionally in first (4, 5) second (2) and third (6) dimensions therein, the reinforcing system being tension interlocked in at least one dimension in that reinforcement components extending in the first and/or second dimension are tension interlocked to reinforcement components extending in the same dimension(s), but at a transverse distance therefrom, by transverse reinforcement components extending in a dimension transverse, to a plane or surface defined by the reinforcement in the first and/or second dimension. The matrix is preferably a dense cement-based matrix prepared from cement, microsilica, a concrete superplaticiser and water, or a metallic matrix.

Abstract: A cement composition consists essentially of (a) from 50% to 97% by weight (calculated on the total composition) of a Portland cement clinker, the sulfur content of which is from 0.5% to 10% by weight expressed as SO.sub.3 and the fluorine content of which is from 0.13% to 1.00% by weight expressed as F, and (b) from 3% to 50% by weight (calculated on the total composition) of an extender containing a carbonate selected from calcium carbonate, magnesium carbonate, calcium magnesium carbonate and mixtures thereof as its main constituent and having a median particle size (d.sub.50) of below 14 .mu.m. Preferably, the total content of C.sub.3 S and C.sub.2 S in the Portland cement clinker is at least 65%. A preferred carbonate is electrostatic precipitator dust extracted from cement kiln exhaust gases. The cement composition may be mixed with further components such as other extenders, retarding agents and aggregate.

Abstract: A cement composition comprising 1) a cement containing water-soluble chromate and 2) at least one manganese(II) compound in an amount sufficient to reduce the amount of water-soluble chromate to at the most 2 mg of Cr(VI) per kg of the cement, the determination of the chromate content being carried out by elution of the composition in water for 15 minutes at a water/cement ratio 1, filtration and determination of the chromate content in the filtrate.