A high performance concrete composition comprising: (i) at least one Class C fly ash, (ii) at least one calcium aluminate cement, (iii) at least one aggregate, and (iv) water.

Disclosed are a polymer cement-granite composite tomb box and a preparation method thereof. The tomb box has a layered structure or an upper-lower composite structure, where the layered structure is composed of one or two layers of granite slabs and one layer of the polymer cement, and an upper portion of the upper-lower composite structure is made of granite slabs, and an lower portion of the upper-lower composite structure is made of the polymer cement or a combination of the polymer cement and the granite slabs.

Disclosed are a polymer cement-granite composite tomb box and a preparation method thereof. The tomb box has a layered structure or an upper-lower composite structure, where the layered structure is composed of one or two layers of granite slabs and one layer of the polymer cement, and an upper portion of the upper-lower composite structure is made of granite slabs, and an lower portion of the upper-lower composite structure is made of the polymer cement or a combination of the polymer cement and the granite slabs.

A cement admixture containing free lime, gypsum, Ye’elimite, and ternesite, wherein the cement admixture has a mass ratio of the Ye’elimite to the ternesite (Ye′elimite/ternesite) of from 0.5 to 40. The cement admixture contains 20 to 80 mass% of the free lime. The cement admixture has a total mass ratio of the free lime and the gypsum anhydride to the ternesite ((free lime + gypsum anhydride)/ternesite) from 20 to 90. An expansive material which contains the cement admixture. A cement composition which contains the cement admixture.

A cement admixture containing free lime, gypsum, Ye’elimite, and ternesite, wherein the cement admixture has a mass ratio of the Ye’elimite to the ternesite (Ye′elimite/ternesite) of from 0.5 to 40. The cement admixture contains 20 to 80 mass% of the free lime. The cement admixture has a total mass ratio of the free lime and the gypsum anhydride to the ternesite ((free lime + gypsum anhydride)/ternesite) from 20 to 90. An expansive material which contains the cement admixture. A cement composition which contains the cement admixture.

A process for producing cement includes combining a cement precursor and a wax, wherein the wax includes alkyl ketene dimer wax and/or alkenyl ketene dimer wax, grinding the cement precursor and the wax to yield cement grains coated with the wax. A cement includes cement powder grains and a coating of wax on the Portland cement powder grains, wherein the wax includes alkyl ketene dimer wax and/or alkenyl ketene dimer wax. A process for making cementitious material includes combining a cement with water to yield a slurry, wherein the cement includes cement powder grains and a coating of wax on the cement powder grains, wherein the wax includes alkyl ketene dimer wax and/or alkenyl ketene dimer wax, and allowing the slurry to set.

A process for producing cement includes combining a cement precursor and a wax, wherein the wax includes alkyl ketene dimer wax and/or alkenyl ketene dimer wax, grinding the cement precursor and the wax to yield cement grains coated with the wax. A cement includes cement powder grains and a coating of wax on the Portland cement powder grains, wherein the wax includes alkyl ketene dimer wax and/or alkenyl ketene dimer wax. A process for making cementitious material includes combining a cement with water to yield a slurry, wherein the cement includes cement powder grains and a coating of wax on the cement powder grains, wherein the wax includes alkyl ketene dimer wax and/or alkenyl ketene dimer wax, and allowing the slurry to set.

To provide a prestressed concrete which can be used for non-primary structural members such as general building members by using a chemical stress induced by an expansive material and a mechanical stress induced by a rust-resistant wire together and achieving reduction in weight and suppression of cracking. A prestressed concrete for non-primary structural members is characterized in that a mechanical stress induced by a tensional material and a chemical stress induced by an expansive material for a concrete are introduced and that the tensional material is a rust-resistant continuous fiber reinforcing wire.

To provide a prestressed concrete which can be used for non-primary structural members such as general building members by using a chemical stress induced by an expansive material and a mechanical stress induced by a rust-resistant wire together and achieving reduction in weight and suppression of cracking. A prestressed concrete for non-primary structural members is characterized in that a mechanical stress induced by a tensional material and a chemical stress induced by an expansive material for a concrete are introduced and that the tensional material is a rust-resistant continuous fiber reinforcing wire.

A method of designing a cement slurry may include: (a) selecting at least a cement and concentration thereof, water and concentration thereof, and, optionally, at least one supplementary cementitious material and a concentration thereof, such that a cement slurry comprising the cement, the water, and, if present, the at least one supplementary cementitious material, meet a density requirement; (b) calculating a thickening time of the cement slurry using a thickening time model; (c) comparing the thickening time of the cement slurry to a thickening time requirement, wherein steps (a)-(c) are repeated if the thickening time of the cement slurry does not meet or exceed the thickening time requirement, wherein the selecting comprises selecting different concentrations and/or different chemical identities for the cement and/or the supplementary cementitious material than previously selected, or step (d) is performed if the thickening time of the cement slurry meets or exceeds the thickening time requirement; and preparing the cement slurry.