Asphalt composition containing ground tire rubber
We disclose a method of making an asphalt composition containing large quantities of ground tire rubber. Over 20% GTR by weight can be used in the asphalt composition without the GTR settling out. The method comprises a series of heating and blending and using a GTR stabilizer.
1. A method for making an asphalt composition containing ground tire rubber comprising the steps of:
a. heating asphalt;
b. blending ground tire rubber with asphalt to form an asphalt and ground tire rubber blend; and
c. adding ground tire rubber stabilizer to the asphalt and ground tire rubber blend,
wherein said ground tire rubber stabilizer comprises a blend of oil, approximately 5-15% diethylenetriamine (DETA) and sodium hydroxide, wherein a 1% solution of said ground tire rubber stabilizer in water has a pH of 11, that allows ground tire rubber particles to remain suspended in the asphalt and ground tire rubber blend.
2. The method of claim 1 wherein said asphalt is heated between 300 and 400 degrees Fahrenheit.
3. The method of claim 1 wherein the ground tire rubber has a particle size of between 30 and 140 mesh.
4. The method of claim 1 wherein final concentration of ground tire rubber is in the range of 1% to 20% by weight.
5. The method of claim 1 wherein the concentration of ground tire rubber stabilizer is in the range of 1% to 3% by weight.
6. An asphalt composition containing suspended ground tire rubber comprising:
a. asphalt;
b. 1% to 20% ground tire rubber by weight; and
c. ground tire rubber stabilizer, wherein the ground tire rubber stabilizer comprises a blend of oil, approximately 5-15% diethylenetriamine (DETA), and sodium
hydroxide, wherein a 1% solution of said ground tire rubber stabilizer in water has a pH of 11.
7. The asphalt composition of claim 6 wherein the concentration of ground tire rubber stabilizer is between 0.1% and 10% by weight.
8. The asphalt composition of claim 6 further comprising an additive to facilitate the action of the ground tire rubber stabilizer.
9. A pavement structure comprising:
a. asphalt;
b. ground tire rubber stabilizer, wherein the ground tire rubber stabilizer comprises a blend of oil, approximately 5-15% diethylenetriamine (DETA), and sodium hydroxide, wherein a 1solution of said ground tire rubber stabilizer in water has a pH of 11; and
c. ground tire rubber in the range of 5% to 20% by weight.