A non-conforming (or barely conforming) fly ash is converted into conforming (or better conforming) fly ash by: (1) obtaining an initial fly ash with at least one non-conforming (or barely conforming) characteristic selected from excess carbon content, low strength activity index, or low SAF as defined by ASTM C-618 and having a D10, D50 and D90; (2) classifying the initial fly ash using one or more air classifiers to produce at least two separate fly ash streams, including fine fly ash and coarse fly ash; (3) collecting the fine fly ash and the coarse fly ash, the fine fly ash having a D90 less than the D90 of the initial fly ash; (4) combining the fine fly ash with an aluminosilicate source to form a modified fly ash having a conforming carbon content, a conforming reactivity index, and a conforming SAF as defined by ASTM C-618.

A non-conforming (or barely conforming) fly ash is converted into conforming (or better conforming) fly ash by: (1) obtaining an initial fly ash with at least one non-conforming (or barely conforming) characteristic selected from excess carbon content, low strength activity index, or low SAF as defined by ASTM C-618 and having a D10, D50 and D90; (2) classifying the initial fly ash using one or more air classifiers to produce at least two separate fly ash streams, including fine fly ash and coarse fly ash; (3) collecting the fine fly ash and the coarse fly ash, the fine fly ash having a D90 less than the D90 of the initial fly ash; (4) combining the fine fly ash with an aluminosilicate source to form a modified fly ash having a conforming carbon content, a conforming reactivity index, and a conforming SAF as defined by ASTM C-618.

A method for controlling the volume expansion of a hydraulically setting composition including steel making slag, the method including a step of adding a silica source to the composition. Furthermore, hydraulically setting compositions obtained by such methods and their uses.

A method for controlling the volume expansion of a hydraulically setting composition including steel making slag, the method including a step of adding a silica source to the composition. Furthermore, hydraulically setting compositions obtained by such methods and their uses.

Disclosed herein are mineral-based composites that comprise gypsum, syngenite, brucite and a hydrated magnesium sulphate mineral, and which are adapted to degrade when buried. Also disclosed herein are mineral mixtures which can be used to produce the mineral-based composites, as well as products, such as plantable containers, formed from the mineral-based composites and which degrade when buried.

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.

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.

The present invention has solved the problems of conventional molding materials, and provides a hydraulic composition for additive manufacturing devices having high strength development, particularly high early strength development, and less generation of gas defect and graphite spheroidization defect. Specifically, the hydraulic composition for additive manufacturing devices of the present invention at least contains calcium aluminate. It is preferable that the hydraulic composition contain 0.5-10 parts by mass of gypsum with respect to 100 parts by mass of the calcium aluminate.

The present invention has solved the problems of conventional molding materials, and provides a hydraulic composition for additive manufacturing devices having high strength development, particularly high early strength development, and less generation of gas defect and graphite spheroidization defect. Specifically, the hydraulic composition for additive manufacturing devices of the present invention at least contains calcium aluminate. It is preferable that the hydraulic composition contain 0.5-10 parts by mass of gypsum with respect to 100 parts by mass of the calcium aluminate.

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.