A method of forming a concrete product includes directly capturing CO.sub.2 from a gas source, the capturing comprising contacting the gas source with an absorption solution having a solvent and a solute, wherein the solvent and/or the solute are capable of reacting with CO.sub.2 to form an anionic compound, adjusting the pH of the absorption solution electrochemically to less than about 7 to release the CO.sub.2 as a concentrated vapor containing CO.sub.2, collecting the concentrated vapor containing CO.sub.2, regenerating the solvent and/or the solute, and optionally collecting the regenerated solvent and/or solute; flowing the concentrated vapor containing CO.sub.2 through a gas processing unit to adjust at least one of a temperature, a relative humidity, or a flow rate of the concentrated vapor containing CO.sub.2; and contacting the concentrated vapor containing CO.sub.2 with a concrete component.

Materials and methods for a rapid and effective way to create a carbon negative self-healing construction material are described. The construction material uses sand aggregates, a trace amount of catalyst, a small dosage of scaffolding material with a crosslinking agent, and a calcium source. The curing is performed at a high temperature for a short period or at room temperature for a long period. The catalyst-driven method to bridge the sand particles results in a dense, stiff, strong, and tough structural material, which upon exposure to calcium source and CO.sub.2 heals itself repeatably.

The present disclosure concerns an aluminosilicate having a Blaine fineness of about 500 m.sup.2/kg to about 3000 m.sup.2/kg and/or a specific surface area of about 4 m.sup.2/g to about 20 m.sup.2/g, as well as the uses thereof. The present disclosure also comprises a dry cementing composition and a mortar or concrete composition, the compositions comprising said aluminosilicate. The present disclosure also comprises a process for the manufacture of aluminosilicate. The process comprises: roasting a spodumene concentrate in an acid medium; leaching the acidic roast spodumene concentrate so as to obtain a mixture comprising a solid comprising the aluminosilicate and a leachate; and separating the aluminosilicate from the leachate in an acid medium, wherein said aluminosilicate contains a calcium concentration of less than about 5%.

A cement composition including a hydraulic cement material, a latent-hydraulic cement material, and a non-hydraulic cement material. Also provided is a method including combining, at a jobsite, the cement composition comprising the hydraulic cement material, the latent-hydraulic cement material, and the non-hydraulic cement material with water to provide a cement slurry, and allowing the cement slurry to harden in the presence of carbon dioxide (CO.sub.2) to provide a hardened cement.

A method including entraining carbon dioxide (CO.sub.2) in a cement slurry composition and subjecting the cement slurry composition to conditions under which the CO.sub.2 achieves and maintains a supercritical state; and allowing the cement slurry composition to harden to form a hardened cement having CO.sub.2 sequestered therein.

The invention provides methods and compositions for treating wash water from concrete production with carbon dioxide. The treated wash water can be reused as mix water in fresh batches of concrete.

Divalent ions are extracted from solids by leaching to form a divalent ion-containing solution. The divalent ion-containing solution is subjected to concentration to form a concentrated divalent ion-containing solution. Precipitation of a divalent ion hydroxide salt is induced from the concentrated divalent ion-containing solution. In other cases, the concentrated divalent ion-containing solution is exposed to carbon dioxide to induce precipitation of a divalent ion carbonate salt.

Methods of processing magnesium silicate materials are described to produce a number of products including magnesium hydroxide. Related methods of use of processed magnesium silicate and other reaction products are described for energy production, cement manufacture and carbon sequestration. In one embodiment the method comprises subjecting a magnesium silicate source to an acid digestion; increasing the digested liquid pH to produce a magnesium salt solution; subjecting the magnesium salt solution to electrolysis; and recovering magnesium hydroxide produced from electrolysis. By-products such as silica, iron oxy(oxides) and others are also described along with further reaction products such as magnesium oxide and magnesium carbonate.

The present invention relates to construction material compositions comprising at most 55% by dry weight of Portland cement with a high early and late compressive strength. The other main components in the cement are SCMs, limestone, sulfate source and accelerator.

Some implementations herein described improvements to concrete products and processes for producing concrete products that may provide a positive environmental impact and that can be stronger relative to the percent of cement used. Particular examples include improvements to zero-slump to near-zero-slump concrete mixture design, material storage and handling, batching, mixing, sequencing and curing processes, as well as forming and curing techniques.