High calcium sulfate expansive clinker

Claim 2

A CALCIUM SULFOALUMINATE CLINKER OF THE (CAO)4(AL2O3)3SO3 TYPE CONTAINING IN THE CLINKER, AND IN PARTICLES RESULTING FROM GRINDING THE CLINKER, AN AMOUNT OF CASO4 AT LEAST ABOUT 50 PERCENT AND SUBSTANTIALLY IN EXCESS OF THAT REQUIRED FOR THE PRODUCTION OF ETTRINGITE ON HYDRATION OF (CAO)4(AL2O3)3SO3.

Claim 3

As a composition of matter, a homogeneous mixture of (CaO)4(Al2O3)3SO3 and CaSO4, the latter exceeding about 50 percent of the weight of the composition.

Claim 4

As a composition of matter, a homogeneous mixture of (CaO)4(Al2O3)3SO3 and CaSO4, the latter exceeding about 50 percent of the weight of the composition.

Claim 5

The composition of claim 2 containing less than about 50 percent of total lime.

Claim 6

The composition of claim 1 ground to a fineness such that at least 70 percent is smaller than 325 mesh.

Claim 7

A process of producing an expansive (CaO)4(Al2O3)3SO3 clinker which comprises forming a mixture of materials which, on heating, provide the oxides CaO, Al2O3 and SO3 and are capable of forming (CaO)4(Al2O3)3SO3, the proportions of such materials being selected to produce an excess of CaSO4 in the resulting clinker above that required for the reaction (CaO)4(Al2O3)3SO3 + 8CaSO4 + 6CaO + 32H2O -> (CaO)6Al2O3SO3 . 32H2O and amounting to at least 50% CaSO4, such excess being substantial and enough to provide, when the resulting clinker is added to portland cement, at least a substantial proportion of the CaSO4 requirement of portland cement, said process comprising heating such mixture of materials sufficiently to form (CaO)4(Al2O3)3SO3 and CaSO4.

Claim 8

A process of producing an expansive (CaO)4(Al2O3)3SO3 clinker which comprises forming a mixture of materials which, on heating, provide the oxides CaO, Al2O3 and SO3 and are capable of forming (CaO)4(Al2O3)3SO3, the proportions of such materials being selected to produce an excess of CaSO4 in the resulting clinker above that required for the reaction (CaO)4(Al2O3)3SO3 + 8CaSO4 + 6CaO + 32H2O -> (CaO)6Al2O3SO3 . 32H2O and amounting to at least 50% CaSO4, such excess being substantial and enough to provide, when the resulting clinker is added to portland cement, at least a substantial proportion of the CaSO4 requirement of portland cement, said process comprising heating such mixture of materials sufficiently to form (CaO)4(Al2O3)3SO3 and CaSO4.

Claim 9

A process for producing a portland cement composition consisting mainly of portland cement which comprises mixing with the portland cement an expansive material consisting mainly of (CaO)4(Al2O3)3SO3 and CaSO4, the CaSO4 component of such expansive material being present in an amount not less than about 65 percent and in excess of the CaSO4 required for the reaction: (CaO)4(Al2O3)3SO2 + 8CaSO4 + 6CaO + 32 H2O -> (CaO)6 Al2O3(SO3)3 . 32H2O

Claim 10

A process for producing a portland cement composition consisting mainly of portland cement which comprises mixing with the portland cement an expansive material consisting mainly of (CaO)4(Al2O3)3SO3 and CaSO4, the CaSO4 component of such expansive material being present in an amount not less than about 65 percent and in excess of the CaSO4 required for the reaction: (CaO)4(Al2O3)3SO2 + 8CaSO4 + 6CaO + 32 H2O -> (CaO)6 Al2O3(SO3)3 . 32H2O

Claim 11

The process of claim 6 wherein the portland cement composition is formed by intergrinding portland cement clinker with the expansive material in clinker form.

Claim 12

A cement composition containing portland cement as its principal ingredient and also containing an expansive component in the form of (CaO)4(Al2O3)3SO3 plus CaSO4 in quantity not less than about 65 percent and sufficient to at least partially compensate for drying shrinkage of concrete made with the cement, the CaSO4 being also in excess of that required to react with the (CaO)4(Al2O3)3SO3 to form ettringite.

Claim 13

A cement composition containing portland cement as its principal ingredient and also containing an expansive component in the form of (CaO)4(Al2O3)3SO3 plus CaSO4 in quantity not less than about 65 percent and sufficient to at least partially compensate for drying shrinkage of concrete made with the cement, the CaSO4 being also in excess of that required to react with the (CaO)4(Al2O3)3SO3 to form ettringite.