Waste to energy ash and engineered aggregate in road construction

Abstract

Described herein are compositions and methods for waste-to-energy ash in engineered aggregate in road construction.

At least the following is claimed: 
     
         1 . A composition comprising waste-to-energy bottom ash (WTE BA) aggregates sized about 9.5 mm to about 19.05 mm, wherein the composition has an aluminum content of about 25,000 mg/kg dry or less. 
     
     
         2 . The composition of  claim 1 , wherein the aluminum content is determined using EPA testing method  3050   b.    
     
     
         3 . The composition of  claim 1 , wherein the composition further comprises about 12% to about 20% of total WTE BA that passes through a 3/8 inch sieve. 
     
     
         4 . The composition of  claim 1 , further comprising water, wherein the WTE BA aggregates and water form an aqueous suspension, wherein the aqueous suspension has a pH of about 11 or less basic. 
     
     
         5 . The composition of  claim 1 , wherein the composition has reacted with CO 2  from a CO 2  source. 
     
     
         6 . A composition of Portland cement concrete, comprising:
 Portland cement concrete; and   a WTE BA aggregate fraction, wherein the WTE BA aggregate fraction contains 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.   
     
     
         7 . The composition of  claim 6 , wherein the aluminum content is determined using EPA testing method  3050   b.    
     
     
         8 . The composition of  claim 6 , wherein the WTE BA aggregate fraction is about 50% or less of the total composition. 
     
     
         9 . The composition of  claim 6 , further comprising coal fly ash. 
     
     
         10 . The composition of  claim 6 , 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. 
     
     
         11 . The composition of  claim 6 , wherein the WTE BA aggregate fraction has reacted with CO 2  from a CO 2  source. 
     
     
         12 . The composition of  claim 6 , wherein the Portland cement concrete comprises:
 tricalcium silicate, dicalcium silicate, tricalcium aluminate, tetracalcium aluminoferrite, free calcium oxide, and sulfur trioxide, individually or in combination.   
     
     
         13 . A composition of hot mix asphalt (HMA), comprising:
 hot mix asphalt; and   a WTE BA aggregate fraction, wherein the WTE BA aggregate fraction contains WTE BA aggregates between 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.   
     
     
         14 . The composition of  claim 13 , wherein the aluminum content is determined using EPA testing method  3050   b.    
     
     
         15 . The composition of  claim 13 , wherein a WTE BA aggregate fraction is about 50% or less of the total composition. 
     
     
         16 . The composition of  claim 13 , wherein a WTE BA aggregate fraction has been mixed with water to form an aqueous suspension, wherein the aqueous suspension has a pH of about 11 or less basic. 
     
     
         17 . The composition of  claim 13 , further comprising coal fly ash. 
     
     
         18 . The composition of  claim 13 , wherein the WTE BA aggregate fraction has reacted with CO 2  from a CO 2  source. 
     
     
         19 . The composition of  claim 13 , wherein the hot mix asphalt comprises: sand, RAP, course aggregate, and screenings, individually or in combination. 
     
     
         20 . A method for altering a composition of waste-to-energy bottom ash (WTE BA), comprising:
 separating WTE BA with a first separation device to isolate a first WTE BA aggregate fraction, wherein the first aggregate fraction contains WTE BA aggregates about 9.5 mm or larger in size; and   separating the first WTE BA aggregate fraction with a second separation device to isolate a second aggregate fraction, wherein the second aggregate fraction contains WTE BA aggregates of about 9.5 mm to about 19.05 mm in size, wherein the second aggregate fraction has an aluminum content of about 25,000 mg/kg dry or less.   
     
     
         21 . The method of  claim 20 , wherein the aluminum content is determined using EPA method  3050   b.    
     
     
         22 . The method of  claim 20 , wherein the first separation device is a 3/8 inch sieve. 
     
     
         23 . The method of  claim 20 , wherein the second separation device is a 3/4 inch sieve. 
     
     
         24 . The method of  claim 20 , further comprising reacting the second aggregate fraction with CO 2  from a CO 2  source. 
     
     
         25 . The method of  claim 20 , further comprising aging the second aggregate fraction after separating the first WTE BA aggregate fraction, wherein aging the second aggregate fraction comprises:
 placing the second aggregate fraction in a lined unit;   adding water to the second aggregate fraction to form an aqueous suspension; and   reacting the aqueous suspension with CO 2  from a CO 2  source over a period of time until the pH of the second aggregate in aqueous suspension is between about 8.0 to about 11.0.