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US 2026/0296967 A1Published application
Recycled Concrete Aggregates Carbonation Treatment
AssigneesHawkins Construction Company, NUtech Ventures
InventorsChris Hawkins, Jim Ball, Nate Harper, Seunghee Kim, Jiong Hu, Amin Hosseini Zadeh, Miras Mamirov
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Abstract
A method of treating recycled concrete aggregates (RCA) that includes constructing a chamber configured to form a hermetic seal, loading the RCA into the chamber, hermetically sealing the chamber, pressurizing the interior of the chamber with carbon dioxide gas, monitoring a pressure and a relative humidity in the interior of the chamber, and controlling the pressure and the relative humidity until a predetermined condition is met.
Claims20
Treated recycled concrete aggregates (RCA), comprising:
- waste concrete that has been collected, crushed, and screened to create the RCA, the RCA being hardened concrete comprising natural aggregates bound together by cement paste, wherein the cement paste comprises calcium hydroxide and calcium silicate hydrate;
- the RCA loaded into and hermetically sealed within a chamber;
- the RCA treated by exposure to carbon dioxide gas within the chamber, the chamber being pressurized with the carbon dioxide gas;
- a pressure, a temperature and a relative humidity of the atmosphere inside the chamber during treatment of the RCA having been monitored and controlled until certain predetermined conditions are met;
- the predetermined conditions comprising:
- a) a treatment time less than approximately 12 hours, wherein the treatment time comprises exposure to pressurized carbon dioxide gas;
- b) a pressure greater than 50 psig;
- c) a temperature between approximately 0° C. and 80° C.;
- and
- d) a relative humidity between approximately 10% and 75%;
- wherein mechanical and chemical properties of the RCA are improved through the treatment.
8 more elements
A method of carbonation of recycled concrete aggregates (RCA), the method comprising:
- collecting, crushing, and screening waste concrete to create the RCA, the RCA being hardened concrete comprising natural aggregates bound together by cement paste, wherein the cement paste comprises calcium hydroxide and calcium silicate hydrate;
- loading the RCA into a hermetically sealed chamber;
- pressurizing an interior of the chamber with carbon dioxide gas;
- monitoring a pressure, a temperature, and a relative humidity in the interior of the chamber;
- controlling the pressure, the temperature, and the relative humidity until certain predetermined conditions are met;
- meeting the predetermined conditions, comprising:
- a) a treatment time less than approximately 12 hours, wherein the treatment time comprises exposure to pressurized carbon dioxide gas;
- b) a pressure greater than 50 psig;
- c) a temperature between approximately 0° C. and 80° C.;
- and
- d) a relative humidity between approximately 10% and 75%;
- wherein mechanical and chemical properties of the RCA are improved through the treatment.
9 more elements
A system for treating recycled concrete aggregates (RCA), the system comprising:
- a chamber configured to form a hermetic seal, the chamber comprising:
- a volume of at least 10 L and no greater than 3×104 L;
- and
- a door configured to form a hermetic seal;
- at least one dehumidifier installed in the chamber and configured to maintain a relative humidity in the chamber;
- at least one fan installed in the chamber and configured to circulate carbon dioxide gas and moisture within the chamber;
- at least one heating element;
- at least one pressure sensor installed and configured to measure a pressure within the chamber;
- at least one relative humidity sensor installed and configured to measure a relative humidity within the chamber;
- at least one temperature sensor installed and configured to measure a temperature within the chamber;
- a supply of carbon dioxide gas operatively connected to the chamber via an injection valve;
- an ejection valve installed on the chamber and configured to allow gas to exit the chamber;
- the system configured to treat the RCA by exposure to carbon dioxide gas within the chamber, the chamber pressurized with the carbon dioxide gas;
- and
- the system configured to monitor and control a pressure, a temperature and a relative humidity of the atmosphere inside the chamber during treatment of the RCA until certain predetermined conditions are met, the predetermined conditions comprising:
- a) a treatment time less than approximately 12 hours, wherein the treatment time comprises exposure to pressurized carbon dioxide gas;
- b) a pressure greater than 50 psig;
- c) a temperature between approximately 0° C. and 80° C.;
- and
- d) a relative humidity between approximately 10% and 75%;
- wherein the system improves mechanical and chemical properties of the RCA through the treatment.
18 more elements
Dependencies are inferred from the claim text.