Method for producing a track superstructure which underwent partial foaming

Abstract

The invention relates to a method for introducing a flowable and foamable reaction mixture from the top into a ballast body having sleepers embedded therein, in which method said mixture is introduced into the ballast body laterally of the sleepers, notably preferably depending on the height of the ballast body at the point of application, and in a quantity that is all the larger the more upwards in the ballast body the application point is situated, wherein the mixture is adjusted in such a way that the foam formation process will begin only when the front of the mixture flowing downwards inside the ballast body has reached the bottom side or the region in the vicinity thereof of the ballast body so that the foam formation is carried out within the ballast body from the bottom towards the top.

1 . A method comprising:
 introducing a flowable and foamable reaction mixture from the top into a ballast body having sleepers embedded therein, wherein the mixture is introduced into the ballast body at the top of the ballast body and laterally of the sleepers, and wherein the mixture is adjusted in such a way that the foam formation process begins only when the front of the mixture flowing downwards inside the ballast body has reached the bottom side or the region in the vicinity thereof of the ballast body so that the foam formation is carried out within the ballast body from the bottom towards the top.   
     
     
         2 . The method of  claim 1 , wherein, prior to the introduction of the mixture, the ballast is first removed between the sleepers and outside the load transfer regions of the ballast body and, after foam formation, is applied again onto the ballast body between the sleepers for UV protection of the surface-near region of the foam. 
     
     
         3 . The method of  claim 1 , wherein the method is used for conditioning a ballast bed, and wherein hot air is introduced from above into the ballast body, which air will laterally emerge from the ballast body, while the relative humidity of the emerging air is detected and the process of heating the ballast body will be terminated when the average humidity of the air is below a presettable threshold value. 
     
     
         4 . The method of  claim 3 , wherein the humidity of the air laterally exiting from the ballast body is detected at a plurality of sites and an average value is obtained from these individual air-humidity values, and that the heating the ballast body is terminated when the average humidity of the air is below a presettable threshold value. 
     
     
         5 . The method of  claim 1 , wherein the mixture is introduced, depending on the height of the ballast body at the point of application, in a quantity that is all the larger the more upwards in the ballast body the application point is situated. 
     
     
         6 . The method of  claim 3 , wherein the mixture is introduced, depending on the height of the ballast body at the point of application, in a quantity that is all the larger the more upwards in the ballast body the application point is situated. 
     
     
         7 . The method of  claim 1 , wherein the mixture comprises a selection of suitable components and additives to cause the foam formation to occur upon a lapse of a certain time after introduction of the mixture into the ballast bed. 
     
     
         8 . The method of  claim 1 , wherein the foam comprises at least one of a polyurethane foam, a polyester foam, a polystyrene foam, or a polyvinyl chloride foam. 
     
     
         9 . The method of  claim 1 , wherein the foam is formed in a load transfer zone that is described by an angle of about 60° beneath the sleepers. 
     
     
         10 . The method of  claim 9 , wherein the foam is formed throughout substantially all of the load transfer zone. 
     
     
         11 . The method of  claim 9 , wherein the load transfer zone comprises a first load transfer zone formed under a first sleeper, further comprising:
 forming the foam in a second load transfer zone formed under a second sleeper adjacent to the first sleeper; and   providing an inclination along an interface between the first load transfer zone and the second load transfer zone to enhance drainage of moisture from the ballast body.   
     
     
         12 . The method of  claim 1 , further comprising bonding surfaces of the ballast body between the sleepers with an ultraviolet-radiation-resistant material. 
     
     
         13 . The method of  claim 1 , wherein introducing the flowable and foamable reaction mixture from the top into the ballast body having sleepers embedded therein comprises pouring the flowable and foamable reaction mixture onto the ballast body.