An activated pozzolan composition includes a fine interground particulate blend of an initially unactivated natural pozzolan and a supplementary cementitious material (SCM) different than the initially unactivated natural pozzolan. The initially unactivated natural pozzolan may include volcanic ash or other natural pozzolanic deposit having a moisture content of at least 3%, and the activated pozzolan composition can have a moisture content less than 0.5% The initially unactivated natural pozzolan may have a particle size less than 1 mm before intergrinding with the SCM. The SCM used to activate the initially unactivated natural pozzolan can be initially coarse or granular with a size greater than 1-3 μm and may include granulated blast furnace slag, steel slag, other metallurgical slag, pumice, limestone, fine aggregate, shale, tuff, trass, geologic material, waste glass, glass shards, basalt, sinters, ceramics, recycled bricks, recycled concrete, refractory materials, other waste industrial products, sand, or natural mineral.

According to some embodiments, a curable mixture configured to set in the presence of water, wherein the mixture comprises magnesium oxide, a primary cementitious component and at least one accelerant. A proportion by weight of the primary cementitious component is 80% to 120% of a proportion of magnesium oxide by weight.

According to some embodiments, a curable mixture configured to set in the presence of water, wherein the mixture comprises magnesium oxide, a primary cementitious component and at least one accelerant. A proportion by weight of the primary cementitious component is 80% to 120% of a proportion of magnesium oxide by weight.

A method of producing a carbonated composite material includes: providing a carbonatable cementitious material in particulate form; mixing the carbonatable cementitious material with water to produce a mix; forming a predetermined shape with the mix, wherein the predetermined shape has an initial pore structure containing an initial pore solution having a first pH; pre-conditioning the predetermined shape to remove a predetermined amount of the water from the predetermined shape to produce a pre-conditioned shape; carbonating the pre-conditioned shape in an environment comprising carbon dioxide to produce a modified pore structure containing a modified pore solution having and a second pH, wherein the difference between the first pH and the second pH is represented by a ΔpH, and the ΔpH is 1.0 or less.

A method of producing a carbonated composite material includes: providing a carbonatable cementitious material in particulate form; mixing the carbonatable cementitious material with water to produce a mix; forming a predetermined shape with the mix, wherein the predetermined shape has an initial pore structure containing an initial pore solution having a first pH; pre-conditioning the predetermined shape to remove a predetermined amount of the water from the predetermined shape to produce a pre-conditioned shape; carbonating the pre-conditioned shape in an environment comprising carbon dioxide to produce a modified pore structure containing a modified pore solution having and a second pH, wherein the difference between the first pH and the second pH is represented by a ΔpH, and the ΔpH is 1.0 or less.

Provided herein are compositions, methods, and systems related to bimodal, trimodal, and/or multi-modal distribution of reactive vaterite cement particles.

An accelerator powder for cement and also rapid-setting binder compositions which contain the accelerator powder and the use in mortar or concrete. The accelerator powder includes from 10 to 99.7% by weight of a water-insoluble mineral powder P and from 0.3 to 90% by weight of at least one compound V selected from the group consisting of alkali metal halides and alkaline earth metal halides, alkali metal nitrates and alkaline earth metal nitrates, alkali metal nitrites and alkaline earth metal nitrites, alkali metal thiocyanates and alkaline earth metal thiocyanates and hydroxyalkylamines or salts thereof, and mixtures thereof.

An accelerator powder for cement and also rapid-setting binder compositions which contain the accelerator powder and the use in mortar or concrete. The accelerator powder includes from 10 to 99.7% by weight of a water-insoluble mineral powder P and from 0.3 to 90% by weight of at least one compound V selected from the group consisting of alkali metal halides and alkaline earth metal halides, alkali metal nitrates and alkaline earth metal nitrates, alkali metal nitrites and alkaline earth metal nitrites, alkali metal thiocyanates and alkaline earth metal thiocyanates and hydroxyalkylamines or salts thereof, and mixtures thereof.

A manufacturing method includes: (1) incorporating at least one soluble, calcium, magnesium, or other divalent cation-containing additive into a concrete mixture including aggregates prone to alkali-silica reaction; and (2) curing the concrete mixture to form a concrete product.

In some variations, the disclosure provides a renewable biocarbon composition comprising from 50 wt% to 99 wt% total carbon, wherein the biocarbon composition is characterized by a base-acid ratio selected from 0.1 to 10, an iron-calcium ratio selected from 0.05 to 5, iron-plus-calcium parameter selected from 5 to 50 wt%, a slagging factor selected from 0.001 to 1, and/or a fouling factor or modified fouling factor selected from 0.1 to 10. Some variations provide a process comprising: providing a biomass feedstock; pyrolyzing the biomass feedstock to generate an intermediate biocarbon stream; washing or treating the intermediate biocarbon stream with an acid, a base, a salt, a metal, H.sub.2, H.sub.2O, CO, CO.sub.2, or a combination thereof, and/or introducing an additive in the process, to adjust a base-acid ratio or other compositional parameter; and recovering a biocarbon composition comprising from 50 wt% to 99 wt% total carbon and optimized for a compositional parameter.