Two Layer Pavement Preservation System

Abstract

A pavement preservation system comprises two layers of specialized chip seal applications. The first layer is a Polymer Modified Asphalt Rubber chip seal application. This layer is composed of an application of Polymer Modified Asphalt Rubber binder followed by a hot pre-coated ⅜ or ½ inch aggregate placed at 28 to 34 pounds per square yard and rolled into the binder material. The second layer is a Rubberized Asphalt Binder chip seal application. This layer is composed of an application of Rubberized Asphalt Binder followed by a hot pre-coated ⅛ inch aggregate placed at 10 to 14 pounds per square yard and rolled into the binder material.

1 . A method for installing a dual layer pavement preservation system, comprising the steps of
 preparing the pavement to receive an asphalt surface;   applying a layer of hot polymer modified asphalt rubber binder;   applying a layer of ⅜ inch or ½ inch aggregate that is hot pre-coated with 0.5 to 1.0 percent asphalt cement;   rolling the aggregate into the binder material;   allowing the combined binder and aggregate to cure;   removing any loose aggregate;   applying a layer of hot rubberized asphalt binder;   applying a layer of ⅛ inch aggregate that is hot pre-coated with 0.5 to 1.0 percent asphalt cement;   rolling the ⅛ inch aggregate into the rubberized asphalt binder material;   allowing the combined binder and ⅛ inch aggregate to cure; and   removing any loose aggregate.   
     
     
         2 . The method of  claim 1  wherein the polymer modified asphalt rubber binder is applied at a rate of about 0.60 to 0.70 gallons per square yard. 
     
     
         3 . The method of  claim 1  wherein the ⅜ or ½ inch aggregate is placed at about 28 to 34 pounds per square yard. 
     
     
         4 . The method of  claim 1  wherein the rubberized asphalt binder is applied at a rate of about 0.20 to 0.23 gallons per square yard. 
     
     
         5 . The method of  claim 1  wherein the ⅛ inch aggregate is placed at about 10 to 14 pounds per square yard. 
     
     
         6 . The method of  claim 1  wherein the polymer modified asphalt rubber binder comprises about 15 to 18 percent by weight of reclaimed tire rubber crumb rubber modifier and about 2 percent by weight of SBS polymer, and the rubberized asphalt binder comprises about 5 to 10 percent by weight of reclaimed tire rubber crumb rubber modifier and about 2 to 4 percent by weight of SBS polymer. 
     
     
         7 . The method of  claim 6  wherein the polymer modified asphalt rubber binder is prepared in a blender unit in which asphalt cement is combined with crumb rubber modifier and SBS polymer at a temperature between about 375° F. and 450° F., reacted in a distributor truck or reaction vessel at a temperature between about 375° F. and 425° F., and applied to the pavement at a temperature between about 375° F. and 400° F. 
     
     
         8 . The method of  claim 6  wherein the rubberized asphalt binder is prepared in a blender unit in which asphalt cement is combined with crumb rubber modifier and SBS polymer at a temperature between about 375° F. and 450° F., reacted in a distributor truck or reaction vessel at a temperature between about 375° F. and 425° F., and applied to the pavement at a temperature between about 375° F. and 400° F. 
     
     
         9 . A dual layer pavement preservation system comprising a polymer modified asphalt rubber chip seal layer in contact with the pavement; and a rubberized asphalt binder chip seal layer on top of the polymer modified asphalt rubber chip seal layer. 
     
     
         10 . The system of  claim 9  wherein the polymer modified asphalt rubber chip seal layer includes a binder comprising performance graded asphalt cement and about 15 to 18 percent by weight of reclaimed tire rubber crumb rubber modifier and about 2 percent by weight of SBS polymer. 
     
     
         11 . The system of  claim 10  wherein the rubberized asphalt binder comprises performance grade asphalt cement and about 5 to 10 percent by weight of reclaimed tire rubber crumb rubber modifier and about 2 to 4 percent by weight of SBS polymer.