Provided are cementitious mixtures and processes for reinforcing a cementitious matrix. In one form of the process for reinforcing a cementitious matrix includes the steps of mixing a mineral cement and one or more populations of synthetic copolymer microfibers including about 1 mol. % to about 25 mol. % and from about 75 mol. % to about 99.5 mol. % of propylene monomeric units.

The invention discloses an in-situ high-strength gradient carbonized material and the preparation method thereof. The in-situ high-strength gradient carbonized material includes a core structure composed of partially calcined calcium carbonate and a shell structure; the shell structure comprises calcium hydroxide and calcium carbonate and covers the outer layer of partially calcined limestone. The invention utilizes an in-situ carbonization reaction to recycle a large amount of low-grade limestone stored or discarded in industry, providing a new technological route for solid waste disposal and resource utilization; this method not only has a green and low-carbon process but also can be widely applied in carbon dioxide capture/collection technology, as well as the preparation of new low-carbon gel materials and concrete.

The invention discloses an in-situ high-strength gradient carbonized material and the preparation method thereof. The in-situ high-strength gradient carbonized material includes a core structure composed of partially calcined calcium carbonate and a shell structure; the shell structure comprises calcium hydroxide and calcium carbonate and covers the outer layer of partially calcined limestone. The invention utilizes an in-situ carbonization reaction to recycle a large amount of low-grade limestone stored or discarded in industry, providing a new technological route for solid waste disposal and resource utilization; this method not only has a green and low-carbon process but also can be widely applied in carbon dioxide capture/collection technology, as well as the preparation of new low-carbon gel materials and concrete.

Disclosed herein are cement compositions and methods of using cement compositions in subterranean formations. An embodiment comprises a method of cementing in a subterranean formation comprising: providing a cement composition comprising water, a pozzolan, hydrated lime, and a zeolite activator; introducing the cement composition into a subterranean formation; and allowing the cement composition to set in the subterranean formation, wherein the zeolite activator accelerates compressive strength development of the cement composition.

Disclosed herein are cement compositions and methods of using cement compositions in subterranean formations. An embodiment comprises a method of cementing in a subterranean formation comprising: providing a cement composition comprising water, a pozzolan, hydrated lime, and a zeolite activator; introducing the cement composition into a subterranean formation; and allowing the cement composition to set in the subterranean formation, wherein the zeolite activator accelerates compressive strength development of the cement composition.

Cementitious compositions comprising lime, which may be foamed or non-foamed compositions, may increase carbon dioxide uptake of the cementitious compositions. Said cementitious compositions may be used in various cementing methods including pre-casting methods, cast-in-place methods, and primary or secondary cementing operations in a wellbore. The carbon dioxide may be added to the cementitious compositions during mixing, during pre-conditioning, during curing, or any combination thereof. Further, the carbon dioxide may be delivered as a gas (e.g., a gas that includes 1 vol % to 100 vol % carbon dioxide) or as a gas-entrained admixture that includes the gas, water, and a foaming agent.

Cementitious compositions comprising lime, which may be foamed or non-foamed compositions, may increase carbon dioxide uptake of the cementitious compositions. Said cementitious compositions may be used in various cementing methods including pre-casting methods, cast-in-place methods, and primary or secondary cementing operations in a wellbore. The carbon dioxide may be added to the cementitious compositions during mixing, during pre-conditioning, during curing, or any combination thereof. Further, the carbon dioxide may be delivered as a gas (e.g., a gas that includes 1 vol % to 100 vol % carbon dioxide) or as a gas-entrained admixture that includes the gas, water, and a foaming agent.

A composition configured to be mixed with cement, and associated systems and methods are disclosed herein. In some embodiments, the composition includes at least 10% by weight lime particles, and at least 35% by weight pozzolan particles. Properties of the composition can include a magnesium oxide concentration of at least 0.5%, and an iron oxide concentration of at least 0.5-2.0%, an aluminum oxide concentration of 2-8%, a silicon dioxide concentration of 20-40%, a potassium oxide concentration of 20,000-30,000 ppm, and a sodium oxide concentration of 10,000-20,000 ppm. In some embodiments, the lime-based cement extender composition, or product, is combined with cement to produce a cement blend for use in the mining industry as mine backfill.

A composition configured to be mixed with cement, and associated systems and methods are disclosed herein. In some embodiments, the composition includes at least 10% by weight lime particles, and at least 35% by weight pozzolan particles. Properties of the composition can include a magnesium oxide concentration of at least 0.5%, and an iron oxide concentration of at least 0.5-2.0%, an aluminum oxide concentration of 2-8%, a silicon dioxide concentration of 20-40%, a potassium oxide concentration of 20,000-30,000 ppm, and a sodium oxide concentration of 10,000-20,000 ppm. In some embodiments, the lime-based cement extender composition, or product, is combined with cement to produce a cement blend for use in the mining industry as mine backfill.

The invention is directed to kits, compositions, tools and methods comprising a cyclic industrial process to form biocement. In particular, the invention is directed to materials and methods for decomposing calcium carbonate into calcium oxide and carbon dioxide at an elevated temperature, reacting calcium oxide with ammonium chloride to form calcium chloride, water, and ammonia gas; and reacting ammonia gas and carbon dioxide at high pressure to form urea and water, which are then utilized to form biocement. This cyclic process can be achieved by combining industrial processes with the resulting product as biocement. The process may involve retention of calcium carbonate currently utilized in the manufacture of Portland Cement.