Road making material, a method of producing a road making material and a road made therefrom

Abstract

The present invention relates to a road making material comprising aggregate, bitumen, and a plastics material, wherein: (a) when the road making material is 10 mm stone mastic asphalt, the bitumen comprises at least 4.7% but no more than 5.69% by weight of the aggregate, bitumen, and plastics material mix; (b) when the road making material is 6 mm, 10 mm, or 20 mm asphaltic concrete, the bitumen comprises at least 3.1% but no more than 4.09% by weight of the aggregate, bitumen, and plastics material mix; (c) when the road making material is hot rolled asphalt, the bitumen comprises at least 4.9% but no more than 5.89% by weight of the aggregate, bitumen, and plastics material mix; or (d) when the road making material is heavy duty 32 mm, the bitumen comprises at least 2.4% but no more than 3.39% by weight of the aggregate, bitumen, and plastics material mix.

What is claimed is: 
     
         1 . A method of producing a road making material comprising:
 (a) heating aggregate;   (b) heating bitumen;   (c) mixing aggregate and bitumen to form an aggregate and bitumen mixture;   (d) after mixing the aggregate and bitumen, adding plastics material to the aggregate and bitumen mixture; and   (e) mixing to incorporate the plastics material with the aggregate and bitumen;   wherein the plastics material comprises high density polyethylene (HDPE) or low density polyethylene (LDPE).   
     
     
         2 . The method of  claim 1 , wherein the aggregate is heated to 130° C.-180° C. 
     
     
         3 . The method of  claim 1 , wherein the bitumen is heated to 130° C.-180° C. 
     
     
         4 . The method of  claim 1 , wherein the aggregate is heated to 165° C. 
     
     
         5 . The method of  claim 1 , wherein the bitumen is heated to 165° C. 
     
     
         6 . The method of  claim 1 , wherein the plastics material is at ambient temperature when added to the aggregate and bitumen mixture. 
     
     
         7 . The method of  claim 1  further comprising heating the plastics material to 120° C.-180° C. before mixing with aggregate and bitumen. 
     
     
         8 . The method of  claim 1 , wherein the plastics material is heated to 165° C. 
     
     
         9 . The method of  claim 1 , wherein the aggregate, bitumen, and plastics material are mixed for at least 30 seconds. 
     
     
         10 . The method of  claim 1 , wherein the aggregate, bitumen, and plastics material are mixed for at least 45 seconds. 
     
     
         11 . The method of  claim 1 , wherein the plastics material is a blend comprising high density polyethylene (HDPE) and low density polyethylene (LDPE). 
     
     
         12 . The method of  claim 11 , wherein said blend comprises 50% high density polyethylene (HDPE) by weight and 50% low density polyethylene (LDPE) by weight, with no other plastics materials or contaminants present in the blend. 
     
     
         13 . The method of  claim 1 , wherein the plastics material is a blend comprising polyvinyl butyral (PVB). 
     
     
         14 . The method of  claim 1 , wherein the plastics material is a blend comprising styrene isoprene styrene (SIS). 
     
     
         15 . The method of  claim 1 , wherein 3 kg of the plastics material is present per 1 tonne of roadmaking material. 
     
     
         16 . The method of  claim 1 , wherein:
 (a) the road making material is 10 mm stone mastic asphalt, the bitumen comprises at least 4.7% but no more than 5.69% by weight of the aggregate, bitumen, and plastics material mix;   (b) the road making material is 6 mm, 10 mm, or 20 mm asphaltic concrete, the bitumen comprises at least 3.1% but no more than 4.09% by weight of the aggregate, bitumen, and plastics material mix;   (c) the road making material is hot rolled asphalt, the bitumen comprises at least 4.9% but no more than 5.89% by weight of the aggregate, bitumen, and plastics material mix; or   (d) the road making material is heavy duty 32 mm, the bitumen comprises at least 2.4% but no more than 3.39% by weight of the aggregate, bitumen, and plastics material mix.   
     
     
         17 . A road making material comprising aggregate, bitumen, and a plastics material, wherein:
 (a) when the road making material is 10 mm stone mastic asphalt, the bitumen comprises at least 4.7% but no more than 5.69% by weight of the aggregate, bitumen, and plastics material mix;   (b) when the road making material is 6 mm, 10 mm, or 20 mm asphaltic concrete, the bitumen comprises at least 3.1% but no more than 4.09% by weight of the aggregate, bitumen, and plastics material mix;   (c) when the road making material is hot rolled asphalt, the bitumen comprises at least 4.9% but no more than 5.89% by weight of the aggregate, bitumen, and plastics material mix; or   (d) when the road making material is heavy duty 32 mm, the bitumen comprises at least 2.4% but no more than 3.39% by weight of the aggregate, bitumen, and plastics material mix.   
     
     
         18 . A method for making a road surface, the method comprising laying a road making material to form a road surface, wherein the road making material comprises aggregate, bitumen, and a plastics material, wherein:
 (a) when the road making material is 10 mm stone mastic asphalt, the bitumen comprises at least 4.7% but no more than 5.69% by weight of the aggregate, bitumen, and plastics material mix;   (b) when the road making material is 6 mm, 10 mm, or 20 mm asphaltic concrete, the bitumen comprises at least 3.1% but no more than 4.09% by weight of the aggregate, bitumen, and plastics material mix;   (c) when the road making material is hot rolled asphalt, the bitumen comprises at least 4.9% but no more than 5.89% by weight of the aggregate, bitumen, and plastics material mix; or   (d) when the road making material is heavy duty 32 mm, the bitumen comprises at least 2.4% but no more than 3.39% by weight of the aggregate, bitumen, and plastics material mix.   
     
     
         19 . A method for making a road surface, the method comprising producing a road making material and laying the road making material to form a road surface, wherein the step of producing comprises:
 (a) heating aggregate;   (b) heating bitumen;   (c) mixing aggregate and bitumen to form an aggregate and bitumen mixture;   (d) adding a plastics material to the aggregate and bitumen mixture; and   (e) mixing to incorporate the plastics with the aggregate and bitumen;   wherein the plastics material comprises high density polyethylene (HDPE) or low density polyethylene (LDPE); and   wherein:   (a) when the road making material is 10 mm stone mastic asphalt, the bitumen comprises at least 4.7% but no more than 5.69% by weight of the aggregate, bitumen, and plastics material mix;   (b) when the road making material is 6 mm, 10 mm, or 20 mm asphaltic concrete, the bitumen comprises at least 3.1% but no more than 4.09% by weight of the aggregate, bitumen, and plastics material mix;   (c) when the road making material is hot rolled asphalt, the bitumen comprises at least 4.9% but no more than 5.89% by weight of the aggregate, bitumen, and plastics material mix; or   (d) when the road making material is heavy duty 32 mm, the bitumen comprises at least 2.4% but no more than 3.39% by weight of the aggregate, bitumen, and plastics material mix.