Abstract:
The invention provides novel paving stones and construction block composite materials and methods for preparation thereof. The paving stones and construction block composite materials can be readily produced from widely available, low cost precursor materials by a production process that involves compacting in a mold that is suitable for large-scale production. The precursor materials include calcium silicate, for example, wollastonite, and particulate filler materials which can comprise silicon dioxide-rich materials. Additives can include calcium carbonate-rich and magnesium carbonate-rich materials. Various additives can be used to fine-tune the physical appearance and mechanical properties of the composite material, such as colorants such as particles of colored materials, such as, and pigments (e.g., black iron oxide, cobalt oxide and chromium oxide). These paving stones and construction block composite materials exhibit visual patterns similar to stone as well as display compressive strength and water absorption equal to or better than that of stone.
Abstract:
The invention provides novel apparatus and processes for gas flow and conditioning to achieve optimal CO2 curing of articles of composite materials (e.g., precast objects made of carbonatable calcium silicate-based cements), with solid interior or having hollow interior ducts, channels and chambers or otherwise being hollowed out, as well as the precast objects so made, which are suitable for a variety of applications in construction, pavements and landscaping, and infrastructure.
Abstract:
The invention provides novel articles of composite materials having hollow interior channels or passageways, or otherwise being hollowed out, and formulations and methods for their manufacture and uses. These hollow core objects are suitable for a variety of applications in construction, pavements and landscaping, and infrastructure.
Abstract:
Apparatus and methods for improving the curing process of materials that cure under reaction with CO2 and that do not cure in the presence of water alone are described, and examples are given.
Abstract:
The invention encompasses methods to control the curing of a CO2 Composite Material (CCM) and processes that use such equipment to cure the CCM. The method provides a way to compute the expected water distribution in an uncured porous concrete product based on a set of environmental conditions on.
Abstract:
A cementitious composition comprising a crystalline phase and an amorphous phase, and an activator selected from the group of materials comprising inorganic bases. In some cases the crystalline phase is gehlenite. In some cases the crystalline phase is anorthite. In some cases the amorphous phase is amorphous calcium aluminum silicate. In some cases the activator is elected from OPC (1-70 wt %), free lime (1-20 wt %), calcium hydroxide (1-20 wt %), and alkali hydroxides (NaOH, KOH 1 to 10 wt %), individually or in combination. A low lime cementitious material is cured by reaction with a curing reagent that includes a reagent chemical that is synthesized from CO2. Examples of such a reagent are oxalic acid and tartaric acid.
Abstract:
A cementitious composition comprising a crystalline phase and an amorphous phase, and an activator selected from the group of materials comprising inorganic bases. In some cases the crystalline phase is gehlenite. In some cases the crystalline phase is anorthite. In some cases the amorphous phase is amorphous calcium aluminum silicate. In some cases the activator is elected from OPC (1-70 wt %), free lime (1-20 wt %), calcium hydroxide (1-20 wt %), and alkali hydroxides (NaOH, KOH 1 to 10 wt %), individually or in combination. A low lime cementitious material is cured by reaction with a curing reagent that includes a reagent chemical that is synthesized from CO2. Examples of such a reagent are oxalic acid and tartaric acid.
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.