A method of preparing a carbonated supplementary cementitious materials, includes carbonating the carbonatable mixture to obtain a first carbonated cementitious material, milling the first carbonated cementitious material, and carbonating the milled mixture to obtain the carbonated supplementary cementitious material.

Provided herein are compositions, methods, and systems related to cement blend composition comprising reactive vaterite cement and supplementary cementitious material (SCM) comprising aluminosilicate material.

Provided herein are methods and systems to form calcium carbonate comprising vaterite, comprising dissolving lime in an aqueous base solution under one or more precipitation conditions to produce a precipitation material comprising calcium carbonate and a supernatant solution, wherein the calcium carbonate comprises vaterite.

Methods and compositions are described for concrete repair using a non-naturally occurring or a synthetic catalyst. The catalyst includes an aromatic hydrocarbon having an active zinc ion configured to facilitate interaction between carbon dioxide and water and to precipitate concrete repairing calcium carbonate crystals. The catalyst is an analog of zinc cyclen, zinc and an indole-based molecule, and zinc tris(2-pyridylmethyl)amine (TPA).

A method for making a carbonated precast concrete product includes: obtaining a mixture including at least one binder material, an aggregate, and water; molding the mixture into a molded intermediate; demolding the molded intermediate to obtain a demolded intermediate, the demolded intermediate having a first water-to-binder ratio; conditioning the demolded intermediate to provide a conditioned article having a second water-to-binder ratio less than the first water-to-binder ratio of the demolded intermediate; moisturizing at least one surface of the conditioned article with an aqueous medium, thereby causing a weight gain of the conditioned article and providing a moisturized product, a first portion of the moisturized product having a third water-to-binder ratio greater than a fourth water-to-binder ratio of a remainder of the moisturized product; and curing the moisturized product with carbon dioxide to obtain the carbonated precast concrete product.

Described are cementitious reagent materials produced from globally abundant inorganic feedstocks. Also described are methods for the manufacture of such cementitious reagent materials and forming the reagent materials as microspheroidal glassy particles. Also described are apparatuses, systems and methods for the thermochemical production of glassy cementitious reagents with spheroidal morphology. The apparatuses, systems and methods make use of an in-flight melting/quenching technology such that solid particles are flown in suspension, melted in suspension, and then quenched in suspension. The cementitious reagents can be used in concrete to substantially reduce the CO.sub.2 emission associated with cement production.

A method of exhaust gas scrubbing includes providing recycled concrete fines as a waste material rich in carbonatable Ca and/or Mg phases and with d.sub.90≤1000 μm and a Rosin-Rammler slope n from 0.6 to 1.4 , injecting the waste material into an exhaust gas stream containing CO.sub.2 and/or SO.sub.x for reaction with CO.sub.2 and/or SO.sub.x at a relative humidity of 50 to 100 Vol.-% and a temperature from 40 to 130° C. in an amount of dry waste material ranging from 5 to 30 kg/m.sup.3, withdrawing a partly carbonated and/or sulphurized waste material and purified exhaust gas, and recycling a part of the partly carbonated and sulphurized waste material while the remainder is discharged, as well as use of a waste material slurry for exhaust gas cleaning of CO.sub.2 and/or SO.sub.x.

A method of sequestering gas-phase materials, hempcrete formed using the method, and methods of using hempcrete are disclosed. An exemplary method includes providing a mixture of hempcrete compound material within a chamber and exposing the mixture within the chamber to a gas for a period of time to form hempcrete, wherein the hempcrete exhibits net-negative life cycle carbon emissions. A model to predict net life cycle carbon emission of hempcrete is also disclosed.

A method for producing a carbonate-containing species-rich, nitrogen-containing species-free solution from a urea-rich solution is proposed. The method comprising the steps of: providing a first reservoir comprising a first mixture including urea and a catalyser comprising an enzymatic catalyser and/or a microorganism; allowing an enzymatic reaction catalysed by the catalyser to decompose urea, thereby obtaining a second mixture comprising nitrogen-containing species and carbonate-containing species; converting at least some of the nitrogen-containing species into gaseous nitrogen-containing species to obtain a third mixture comprising the gaseous nitrogen-containing species and the carbonate-containing species; filtering the third mixture by a gas- permeable filter, thereby separating at least some of the gaseous nitrogen-containing species from the carbonate-containing species while keeping the catalyser away from the gas-permeable filter; and collecting the so-obtained carbonate-containing species-rich, nitrogen-containing species-free solution.

A cement admixture containing one kind or two or more kinds of non-hydraulic compound(s) selected from γ-2CaO.Math.SiO.sub.2, 3CaO.Math.2SiO.sub.2, α-CaO.Math.SiO.sub.2, and calcium magnesium silicate, wherein the non-hydraulic compound contains Li, and the content rate of the Li is 0.001 to 1.0% by mass in terms of oxide. Such admixtures may contain, as chemical components, 0.001 to 1.0 parts by mass of Li.sub.2O, 45 to 70 parts by mass of CaO, 30 to 55 parts by mass of SiO.sub.2, and 0 to 10 parts by mass of Al.sub.2O.sub.3 in 100 parts by mass of the cement admixture.