Stability-enhancing admixture and improved base stabilization process for use in roadway construction and reconstruction

Abstract

The present invention provides a process for stabilizing the base course of a roadway through steps including admixing an asphalt emulsion and Portland cement with granulated base materials. The base course formed through this process is stronger and less permeable than base materials stabilized with either Portland cement or an asphalt emulsion alone. The method of base stabilization includes the steps of evaluating the base materials, designing a proportional mixture of the base materials and stabilizing agents, and forming a stabilized base course.

1 . A method of stabilizing base material for use in the construction of the base course of a roadway comprising: 
 providing granulated base material;    admixing between approximately 1.0% and approximately 12.0% by weight of Portland cement into the granulated base material; and,    admixing between approximately 0.5% and approximately 6.0% of an asphalt emulsion by weight in o the granulated base materials.    
   
   
       2 . (canceled)  
   
   
       3 . A stabilized admixture for use in the construction of the base course of a roadway comprising: 
 granulated base material;    a predetermined amount of Portland cement; and,    a predetermined amount of an asphalt emulsion.    
   
   
       4 . The stabilized admixture of  claim 3 , wherein the asphalt emulsion includes at least one asphalt, at least one emulsifier, and water.  
   
   
       5 . A method of forming a stabilized base course during roadway construction comprising the steps of: 
 providing granulated base material;    admixing a between approximately 1.0% and approximately 12.0% by weight of Portland cement into granulated base material;    admixing between approximately 0.5% and approximately 6.0% of an asphalt emulsion by weight of an asphalt emulsion into the granulated base material;    mixing the granulated base material, asphalt emulsion and Portland cement to form an evenly distributed mixture of stabilized base materials;    spreading the stabilized base course materials onto a roadway construction site; and,    compacting the stabilized base course materials.    
   
   
       6 . The method of  claim 5 , further comprising the step of reclaiming and pulverizing the pavement course of a roadway to form granulated base material.  
   
   
       7 . A method of making a stabilized base course during roadway construction comprising the steps of: 
 evaluating the base material;    designing and testing a proportional mixture of the base materials, Portland cement and an asphalt emulsion; and,    forming a stabilized base course through the addition of with a predetermined amount of Portland cement and a predetermined amount of asphalt emulsion.    
   
   
       8 . A method of improving base course stability during construction of a roadway comprising: 
 forming a stabilized base course through admixing granulated base material to a predetermined amount of Portland cement and a predetermined amount of asphalt emulsion.    
   
   
       9 . The method of  claim 8 , wherein the predetermined amount of Portland cement is between approximately 1.0% and approximately 12.0% of Portland cement by weight of the granulated base materials.  
   
   
       10 . The method of  claim 8 , wherein approximately 3.0% and approximately 10.0% of Portland cement by weight of the granulated base material.  
   
   
       11 . The method of  claim 8 , wherein the predetermined amount of Portland cement is between approximately 4.0% and approximately 8.0% by weight of the granulated base material.  
   
   
       12 . The method of  claim 8 , wherein the predetermined amount of an asphalt emulsion is between approximately 0.5% and approximately 6.0% of by weight of the granulated base materials.  
   
   
       13 . The method of  claim 8 , wherein the predetermined amount of an asphalt emulsion is between approximately 0.75% and approximately 4.0% of an asphalt emulsion by weight of the granulated base materials.  
   
   
       14 . The method of  claim 8 , wherein the predetermined amount of an asphalt emulsion is between approximately 1.0% and approximately 3.0% of an asphalt emulsion by weight of the granulated base materials.  
   
   
       15 . The method of  claim 8 , wherein the asphalt emulsion includes between approximately 50.0% and approximately 70.0% of asphalt solids, by weight, and between approximately 0.3% and approximately 6.0% of emulsifier, by weight.  
   
   
       16 . A method of increasing the strength and decreasing the permeability of a base course during roadway construction comprising: 
 forming a stabilized base course through combining granulated base material with a predetermined amount of Portland cement and a predetermined amount of asphalt emulsion.