Reduced-carbon footprint concrete compositions
Reduced-carbon footprint concrete compositions, and methods for making and using the same, are provided. Aspects of the reduced-carbon footprint concrete compositions include CO 2 -sequestering carbonate compounds, which may be present in the hydraulic cement and/or aggregate components of the concrete. The reduced-carbon footprint concrete compositions find use in a variety of applications, including use in a variety of building materials and building applications.
1. A method comprising:
a) producing synthetic carbonates from a divalent cation-containing solution and an industrial waste gas comprising CO 2 ;
b) producing from the synthetic carbonates
i) a first material comprising a supplementary cementitious material comprising carbonates, bicarbonates, or a combination thereof, wherein the supplementary cementitious material reacts with a hydraulic cement composition, and additionally
ii) a second material comprising a concrete component comprising carbonates, bicarbonates, or a combination thereof selected from the group consisting of cement, aggregate, and pozzolanic material; and
c) incorporating the supplementary cementitious material into a concrete composition.
2. The method of claim 1 , wherein at least one of the synthetic carbonates comprise aragonite, hydromagnesite, monohydrocalcite, or a combination thereof.
3. The method of claim 1 , wherein the synthetic carbonates have a δ 13 C less than −10‰.
4. The method of claim 1 , wherein the synthetic carbonates have a δ 13 C less than −20‰.
5. The method of claim 1 , wherein the synthetic carbonates have a δ 13 C less than −30‰.
6. The method of claim 1 , further comprising incorporating the concrete component into the concrete composition.
7. The method of claim 6 , wherein the concrete component comprises aggregate.
8. The method of claim 1 or claim 6 , further comprising determining a carbon footprint for the concrete composition, wherein determining the carbon footprint consists essentially of the steps of
i) multiplying the number of pounds of a concrete component per cubic yard of the concrete component by the number of pounds of carbon dioxide per pound of the concrete component to obtain a multiplication product;
ii) repeating step i) for each concrete component in the concrete composition;
iii) summing the one or more multiplication products corresponding to the concrete composition to obtain the carbon footprint for the concrete composition.
9. The method of claim 8 wherein the concrete composition is a reduced-carbon concrete composition, such that a cubic yard of the reduced-carbon footprint concrete composition has a carbon footprint that is less than a carbon footprint of a cubic yard of an ordinary Portland concrete composition consisting essentially of ordinary Portland cement produced by a process of calcining a carbonate source, water, fine aggregate, and coarse aggregate, the carbon footprint for the ordinary Portland concrete composition being as determined in steps i)-iii) of claim 8 .
10. The method of claim 9 , wherein the reduced-carbon footprint concrete composition has a carbon footprint that is at least 25% less than the carbon footprint of the ordinary Portland concrete composition.
11. The method of claim 9 , wherein the reduced-carbon footprint concrete composition has a carbon footprint that is at least 50% less than the carbon footprint of the ordinary Portland concrete composition.
12. The method of claim 9 , wherein the reduced-carbon footprint concrete composition has a carbon footprint that is at least 75% less than the carbon footprint of the ordinary Portland concrete composition.
13. The method of claim 8 , wherein the reduced-carbon footprint concrete composition has a carbon footprint that is neutral.
14. The method of claim 8 , wherein the reduced-carbon footprint concrete composition has a carbon footprint that is negative.
15. The method of claim 14 , wherein the negative carbon footprint is −250 lbs CO 2 /yd 3 or less.
16. The method of claim 14 , wherein the negative carbon footprint is −500 lbs CO 2 /yd 3 or less.