Abstract:
An aerated composite material produced from carbonatable calcium silicate compositions (carbonation cured AAC) that has a compressive strength equivalent to autoclaved aerated concrete (ordinary AAC) at substantially the same density and a process of production of the same are provided. The composite material of the present invention comprises: a plurality of bonding elements, each including a core comprising calcium silicate, a first layer which partially or fully surrounds the core and is rich in SiO2, and a second layer which partially or fully surrounds the first layer and is rich in CaCO3; a plurality of filler particles having their particle sizes ranging from 0.1 μm to 1000 μm; and a plurality of voids; wherein the plurality of bonding elements and plurality of filler particles together form a bonding matrix and are substantially evenly dispersed in the matrix and bonded together, the plurality of voids are bubble-shaped and/or interconnected channels, a pore volume with a radius of 0.004 μm to 10.0 μm in the plurality of voids is 0.30 ml/composite material 1 g or less, and a estimated compressive strength expressed by the following formula (1): estimated compressive strength (absolute dry density=0.50)=compressive strength×(0.50÷absolute dry density)2 is 2.0 N/mm2 or greater.
Abstract:
A method of making a carbonated supplementary cementitious material is described that includes: selecting a raw material; reacting the raw material to form a synthetic formulation that can undergo a carbonation reaction; reacting the synthetic formulation with CO2 in the presence of water to form a carbonated supplemental cementitious material comprising calcium silicate and amorphous silica; subjecting the supplemental cementitious material to one or more of deagglomeration and grinding to produce a particle size distribution having a d10 of 1-5 μm and a d50 of 8-15 μm.
Abstract:
Synthetic pozzolans are produced using local materials to provide a cementitious material that is uniform in chemistry and properties independent of the location where the materials are obtained. Two methods of production are described. One is a high temperature process in which materials are processed in a semi-molten or molten state. The second process is a low temperature aqueous process.
Abstract:
Synthetic pozzolans are produced using local materials to provide a cementitious material that is uniform in chemistry and properties independent of the location where the materials are obtained. Two methods of production are described. One is a high temperature process in which materials are processed in a semi-molten or molten state. The second process is a low temperature aqueous process.
Abstract:
Calcium silicate-based cements and concretes are disclosed, which result in concrete compositions that have an increased durability. A cement product includes a plurality of particles of a carbonatable calcium silicate cement and a hydrophobic organic acid, or a salt thereof, or a silane, or a polysiloxane.
Abstract:
A method of making a supplementary cementitious material is described that includes: forming a slurry comprising water and a carbonatable material powder, wherein a weight ratio of water to the carbonatable material powder is at least 1; and flowing a gas comprising carbon dioxide into the slurry for 0.5 to 24 hours while maintaining the slurry at a temperature of 1° C. to 99° C. to form a carbonated slurry comprising CaCO3 and amorphous silica. A method of forming cement or concrete using the supplemental cementitious material is also described.
Abstract:
A method of producing a carbonated composite material is described that 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, 0.75 or less, 0.5 or less, 0.25 or less, or about 0.0. A calcium silicate composition including solid components and liquid components having improved pore solution pH stability is also disclosed.
Abstract:
Synthetic pozzolans are produced using local materials to provide a cementitious material that is uniform in chemistry and properties independent of the location where the materials are obtained. Two methods of production are described. One is a high temperature process in which materials are processed in a semi-molten or molten state. The second process is a low temperature aqueous process.
Abstract:
A method of curing a low Ca/Mg cement composition is described that includes providing a predetermined quantity of the low Ca/Mg cement composition in uncured form; and reacting the uncured low Ca/Mg cement composition with a reagent chemical for a time sufficient to cure said cementitious material, wherein said reagent chemical is a compound synthesized from CO2 and comprises dicarboxylic acids, tricarboxylic acids, or alpha-hydroxycarboxylic acids.
Abstract:
The invention provides methods and compositions that prevent, mitigate or delay the onset of corrosion of iron or steel (e.g., plain carbon steel) components used as reinforcement or otherwise at least partially embedded in carbonated concrete composite materials and objects based on carbonatable calcium silicate cement.