Methods for preparing a carbonated supplementary cementitious materials, including semi-wet carbonation, cyclic carbonation, non-slurry carbonation, high temperature carbonation and/or granular carbonation of a carbonatable material.

Methods for preparing a carbonated supplementary cementitious materials, including semi-wet carbonation, cyclic carbonation, non-slurry carbonation, high temperature carbonation and/or granular carbonation of a carbonatable material.

The invention relates to a geopolymer grout for protecting prestressing reinforcements, the geopolymer grout comprising metakaolin, fly ash and an activator mixture, the activator mixture comprising sodium hydroxide and sodium silicate, wherein the molar ratio Na.sub.2O:SiO.sub.2 of the sodium silicate is between 0.40 and 0.70.

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.

The present invention lies within the field of construction materials and concerns a process for separating the constituents of hardened concrete, with the aim of extracting the cementitious fraction to be used in the production of thermoactivated recycled cement, involving the essential steps of: (a) crushing the concrete waste; (b) screening the crushed material to separate material smaller than about 1 mm; (c) fragmenting material larger than 1 mm; (d) screening material smaller than 1 mm into various granulometric fractions; (e) high intensity magnetic separation of the material; (f) grinding of the cementitious fraction resulting from the magnetic separation in the previous step to a size that allows its efficient thermoactivation; and (g) obtaining a thermoactivated recycled cement.

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 geopolymer composite binder is provided herein, the composite binder including (i) at least one fly ash material having less than or equal to 15 wt % of calcium oxide; (ii) at least one gelation enhancer; and (iii) at least one hardening enhancer having a different composition from a composition of the at least one fly ash material.

The method is for use with a substrate having a plurality of parallel channels extending therethrough. In the method, the steps comprise: filling a selected plurality of the channels with a granular material; and consolidating the granular material through heat. The selected plurality of channels is selected to produce a wall that separates the substrate into: a first portion having a first plurality of the parallel channels extending therethrough; and a second portion having a second plurality of the parallel channels extending therethrough.

A method for the manufacture of a high alumina hydraulic binder comprising hydrating a source of aluminium ions with a source of calcium ions in the presence of water to form mineral hydrates and subsequently heating said mineral hydrates to form said high alumina hydraulic binder.

Lithium-treated calcium aluminate cement (CAC)-based products, concretes, and related techniques are disclosed. In accordance with some embodiments, a lithium-treated CAC mixture may be produced by intergrinding ground-down CAC, class C fly ash, a lithium compound, and a polycarboxylate material. In accordance with some embodiments, a cementitious material may be produced by intergrinding said lithium-treated CAC mixture with class C fly ash, sodium citrate, and a polycarboxylate material. In accordance with some embodiments, a concrete may be produced by mixing said cementitious material (including said lithium-treated CAC mixture) with rock, sand, and water.