RUBBERIZED ASPHALT PELLETS
A storage-stable rubberized asphalt paving pellet can include fines in the core. The core can be an asphalt-based binder at about 70% to about 95% by weight of the core. The asphalt-based binder can include: ground tire rubber from about 15% to about 30% by weight of the asphalt-based binder, and pavement grade asphalt from about 85% to about 70% by weight of the asphalt based binder. The core can include fines at about 30% to about 1% by weight of the core. The shell coating the core can provide the pellet with a maximum dimension of about 1/16 inch to about 2 inches. The shell can include a water-resistant polymer or wax, or a coating of fines. In one aspect, the fines are lime fines or ground asphalt pavement fines. Optionally, the fines can be mineral or rock fines as described herein.
1 . A storage-stable asphalt paving pellet, comprising:
a core comprising:
ground tire rubber from about 15% to about 30% by weight of the core; and
pavement grade asphalt from about 85% to about 70% by weight of the core; and
a shell coating the core such that the pellet has a maximum dimension of about 1/16 inch to about 2 inches, the shell comprising:
a water-resistant polymer or wax; or
fines.
2 . A pellet as in claim 1 , characterized by one or more of the following:
the ground tire rubber at about 15% to about 25% by weight of the total pellet;
the pavement grade asphalt at about 50% to about 60% by weight of the total pellet;
the core having less than about 10% by weight being sulfur;
the fines are lime fines at less than about 40% by weight of the total pellet; or
the coating is wax.
3 . A storage-stable asphalt paving pellet, comprising:
a core comprising:
an asphalt-based binder at about 70% to about 95% by weight of the core, the asphalt-based binder comprising:
ground tire rubber from about 15% to about 30% by weight of the asphalt-based binder; and
pavement grade asphalt from about 85% to about 70% by weight of the asphalt based binder; and
fines at about 1% to about 45% by weight of the core; and
a shell coating the core such that the pellet has a maximum dimension of about 1/16 inch to about 2 inches, the shell comprising:
a water-resistant polymer or wax; or
fines.
4 . A pellet as in claim 3 , wherein the fines are lime fines or ground asphalt pavement fines.
5 . A pellet as in claim 3 , characterized by one or more of the following:
the ground tire rubber at about 15% to about 25% by weight of the total pellet;
the pavement grade asphalt at about 50% to about 60% by weight of the total pellet;
the core having less than about 10% by weight being sulfur;
the fines are lime fines between about 35% to about 45% by weight of the total pellet; or
the coating is wax.
6 . A pellet as in claim 3 , characterized by one or more of the following:
the ground tire rubber from about 20% to about 26% by weight of the asphalt-based binder;
the pavement grade asphalt from about 74% to about 80% by weight of the asphalt based binder; or
the fines are lime fines at less than about 40% by weight of the total pellet.
7 . A pellet as in claim 6 , further comprising one or more of the following:
rock and/or mineral fines;
an additional bituminous binder;
a non-bituminous binder;
a structural additive;
a colorant;
a salt; or
a rheology-modifier.
8 . A pellet as in claim 7 , wherein the non-bituminous binder is selected from the group of hydrophobic binders, cellulosic binders, hydrophilic binders, organic binders, natural polymer binders, lignin and/or lignosulfonate or acid thereof, polysaccharide or modified polysaccharide binder, or combinations thereof.
9 . A method of manufacturing the pellet of claim 3 , the method comprising:
obtaining the ground tire rubber;
obtaining the pavement grade asphalt;
reacting the ground tire rubber and pavement grade asphalt for at least 45 minutes to form a reaction mixture;
combining the reaction mixture with fines to form the core; and
coating the core with a shell to form the pellet.
10 . A method as in claim 9 , wherein the reacting is conducted at about 350 to about 380 degrees F.
11 . A method as in claim 10 , characterized by one or more of the following:
reacting the ground tire rubber at about 15% to about 25% by weight of the total pellet with the pavement grade asphalt at about 50% to about 60% by weight of the total pellet;
reacting the ground tire rubber from about 20% to about 26% by weight of the asphalt-based binder with the pavement grade asphalt from about 74% to about 80% by weight of the asphalt based binder;
inhibiting the core from having more than about 10% by weight being sulfur;
inhibiting the amount of fines to be more than about 45% by weight of the total pellet;
spraying the water-resistant coating onto the pellet; or
applying the fines as a coating onto the pellet.
12 . A method as in claim 11 , further comprising one or more of the following:
combining rock and/or mineral fines with the reaction mixture with fines to form the core;
combining an additional bituminous binder with the reaction mixture with fines to form the core;
combining a non-bituminous binder with the reaction mixture with fines to form the core;
combining a structural additive the reaction mixture with fines to form the core;
combining a colorant with the pellet;
combining a salt with the reaction mixture with fines to form the core; or
combining a rheology-modifier with the reaction mixture with fines to form the core.
13 . A method pellet as in claim 12 , wherein the non-bituminous binder is selected from the group of hydrophobic binders, cellulosic binders, hydrophilic binders, organic binders, natural polymer binders, lignin and/or lignosulfonate or acid thereof, polysaccharide or modified polysaccharide binder, or combinations thereof.
14 . A method as in claim 10 , wherein the fines consist essentially of calcium hydroxide.
15 . A method as in claim 10 , wherein the fines consist essentially of calcium oxide.
16 . A method of preparing a paving asphalt composition, the method comprising:
providing the asphalt pellet of claim 1 ;
heating the asphalt pellets into a liquefied asphalt composition; and
combining the liquefied asphalt composition with aggregate.
17 . A method as in claim 16 , wherein the aggregate is at least 90% by weight of the hot mix asphalt.
18 . A method as in claim 17 , further comprising adding additional pavement grade asphalt to the liquefied asphalt composition, wherein the additional pavement grade asphalt is an amount from about 1% to about 5% of the amount of the asphalt pellet.
19 . A method of preparing hot mix asphalt, the method comprising:
providing the asphalt pellet of claim 3 ;
heating the asphalt pellets into a liquefied asphalt composition; and
combining the liquefied asphalt composition with aggregate.
20 . A method as in claim 19 , wherein the aggregate is at least 90% by weight of the hot mix asphalt.
21 . A method as in claim 20 , further comprising adding additional pavement grade asphalt to the liquefied asphalt composition, wherein the additional pavement grade asphalt is an amount from about 1% to about 5% of the amount of the asphalt pellet.
22 . A method as in claim 20 , wherein the heating is performed at a temperature lower than 325 degrees F.
23 . A method as in claim 22 , wherein the heating is performed at a temperature range from about 270 degrees F. to about 290 degrees F.
24 . A method as in claim 23 , wherein the heating is at about 280 degrees F.
25 . An asphalt pellet product, comprising:
a bag; and
about 25 to about 100 pounds of the asphalt pellet of claim 1 in the bag.
26 . An asphalt pellet product, comprising:
a bag; and
about 25 to about 100 pounds of the asphalt pellet of claim 3 in the bag.