Method for beneficiating recycled concrete aggregate and paste, and recycled concrete aggregate and recycled cementitious materials produced thereby
AssigneeUrban Mining Industries, LLC
InventorsLouis P. Grasso, JR., Dale Hauke
Life of this patent
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Abstract
Methods and systems are provided for processing post-consumer waste concrete into a usable recycled aggregate and supplementary cementitious material. The concrete is crushed and tumbled under heat and optional watering to liberate unreacted hardened cement paste. The aggregate is then screened for size for application, and the hardened cement paste is milled into a supplementary cementitious material, which can be used alone or blended with other supplementary cementitious materials such as ground glass pozzolan.
Claims30
A method for removing hardened cement paste from aggregate in a post-consumer crushed concrete material, comprising:
- obtaining a post-consumer crushed concrete material including aggregate coated with residual hardened cement paste of a surface area of the aggregate;
- and
- processing the post-consumer crushed concrete material in a rotary drum with lifters,
- whereby the processing exposes at least 30% more of the surface area of the aggregate in the sample of the post-consumer crushed concrete material to be free of residual paste.
A method of manufacturing a supplementary cementitious material, comprising:
- liberating hardened cement paste from the surface of post-consumer recycled concrete aggregate;
- and
- fine grinding the hardened cement paste to liberate unreacted cement.
A post-consumer recycled aggregate having a surface with a surface area that is at least 30% free of hardened cement paste.
A post-consumer recycled aggregate made by the process of:
- obtaining post-consumer crushed concrete material;
- and
- abrading the post-consumer crushed concrete material in a rotary drum with lifters, the rotary drum having a first end, a second end, a longitudinal axis extending between the first and second ends, an entrance at the first end, and an exit at the second end such that the post-consumer crushed concrete material is moved from the entrance toward the exit during the processing,
- whereby the processing while in the rotary drum results in removal of at least 30% percent of the hardened cement paste from the surface of the aggregate.
A supplementary cementitious material (SCM) made by the process of:
- processing waste recycled concrete to liberate the unreacted cement;
- and
- milling the unreacted cement.
Dependencies are inferred from the claim text.