Waste to energy ash and engineered aggregate in road construction
Described herein are compositions and methods for waste-to-energy ash in engineered aggregate in road construction.
1. A composition comprising:
Portland cement concrete; and
a waste-to-energy bottom ash (WTE BA) aggregate fraction, wherein the WTE BA aggregate fraction consists of WTE BA aggregates of about 9.5 mm to about 19.05 mm in size, wherein the aggregate fraction has an aluminum content of about 25,000 mg/kg dry or less.
2. The composition of claim 1 , wherein the Portland cement concrete comprises Type I Portland cement, Type II Portland cement, or a combination thereof.
3. The composition of claim 1 , wherein the Portland cement concrete comprises tricalcium silicate, dicalcium silicate, tricalcium aluminate, tetracalcium aluminoferrite, free calcium oxide, sulfur trioxide, or any combination thereof.
4. The composition of claim 1 , wherein the aluminum content is determined using EPA testing method 3050b.
5. The composition of claim 1 , wherein the WTE BA aggregate fraction is about 50% or less of the total composition.
6. The composition of claim 1 , wherein the WTE BA aggregate fraction is from about 25% to about 50% of the total composition.
7. The composition of claim 1 , wherein from about 12% to about 20% of the WTE BA aggregate fraction passes through a ⅜ inch sieve.
8. The composition of claim 1 , further comprising coal fly ash.
9. The composition of claim 8 , wherein the Portland cement concrete comprises from about 2% to about 4% coal fly ash by weight.
10. The composition of claim 1 , further comprising silica fume.
11. The composition of claim 10 , wherein the Portland cement concrete comprises from about 0.5% to about 1.5% of the silica fume by weight.
12. The composition of claim 1 , wherein the WTE BA aggregate fraction has been mixed with water to form an aqueous suspension, wherein the aqueous suspension has a pH of about 8 to about 11.
13. The composition of claim 1 , wherein the WTE BA aggregate fraction has reacted with CO 2 from a CO 2 source.
14. The composition of claim 1 , further comprising lime rock, sand, water, crushed stone, gravel, recycled concrete aggregate, recycled asphalt pavement, or any combination thereof.
15. An ash-amended pavement comprising the composition of claim 1 .
16. The ash-amended pavement of claim 15 , wherein the ash-amended pavement leaches a lower amount of molybdenum relative to an identical pavement that has not been ash-amended.
17. The ash-amended pavement of claim 15 , wherein the ash-amended pavement has a compressive strength of at least about 20 MPa.
18. The ash-amended pavement of claim 15 , wherein the ash-amended pavement exhibits a wet length change after 110 days of less than 0.1%.
19. The ash-amended pavement of claim 15 , wherein the ash-amended pavement exhibits a dry length change after 110 days of less than 0.1%.
20. The ash-amended pavement of claim 15 , wherein the ash-amended pavement comprises a difference in surface resistivity difference of less than or equal to about 5 kΩ·cm compared to an identical pavement that has not been ash-amended.