Abstract:
The invention provides compositions and methods directed to carbonation of a cement mix during mixing. The carbonation may be controlled by one or more feedback mechanisms to adjust carbon dioxide delivery based on one or more characteristics of the mix or other aspects of the mixing operation.
Abstract:
The invention provides methods and compositions for treating wash water from concrete production with carbon dioxide. The treated wash water can be reused as mix water in fresh batches of concrete.
Abstract:
The invention provides methods and compositions for increasing stiffness or rate of stiffening of concrete mixes by carbonation of the mix, preferably while viscosity remains at a level suitable for the intended use of the concrete mix.
Abstract:
Compositions and methods are provided for a system in which liquid carbon dioxide, or a mixture of liquid and gaseous carbon dioxide, is converted to solid carbon dioxide by exiting an orifice at a sufficient pressure drop, e.g., for delivery of carbon dioxide to a concrete mixture in a mixer.
Abstract:
Provided herein are compositions and methods for carbonating wash water (reclaimed water) produced in the manufacture and use of concrete, and subsequent uses of the carbonated reclaimed water, including its use in production and use of further batches of concrete.
Abstract:
The invention provides methods and compositions for carbonation of a wet cement mix. The wet cement mix may be carbonated prior to addition of aggregates, admixture, SCM, and/or other components to produce a carbonated concrete mix. The methods and compositions may include high shear mixing of a cement or concrete mix, either during or before carbonation.
Abstract:
A process for producing a blended binder material containing high calcium fly ash, in particular ASTM Class C fly ash, is provided. The process comprises: (i) carbonating the fly ash with carbon dioxide; and (ii) combining the carbonated fly ash with a cement binder such as Portland cement. The carbonation process improves the performance of the high calcium fly ash and thus allows for higher amounts of the fly ash to be used with the cement binder in cement mix compositions such as concrete. The results presented herein demonstrate the benefits of the carbonation process on the rate of cement hydration, and on the compressive strength and the dimensional stability of the resulting cement products.
Abstract:
The invention provides compositions and methods directed to carbonation of a cement mix during mixing. The carbonation may be in a stationary mixer or a transportable mixer, such as a drum of a ready-mix truck.