Abstract:
A method of fabricating a composite road surface in cold climates for ice roads. In one embodiment the road surface includes: a combination of water and sawdust that is placed on the road surface and frozen. The composite road surface may include a base layer of ice, a color layer over the base layer and a cover layer over the color layer, the cover layer being worn or removed exposing the color layer.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]    This is a continuation of U.S. patent application Ser. No. 11/977,325, filed Oct. 25, 2007 and entitled REINFORCED ICE FOR ROAD SURFACES AND A METHOD OF FABRICATING THEREOF. 
     
    
     TECHNICAL FIELD OF THE INVENTION  
       [0002]    The present invention is directed, in general, to the use of reinforced ice for road surfaces over water. 
       BACKGROUND OF THE INVENTION  
       [0003]    In cold climates roads are made out of ice over naturally frozen lakes and other bodies of water to permit the transport of goods and materials to outlying areas by trucks, automobiles and other vehicles. The current method making roads out of ice, or ice roads, is to allow a body of water to freeze and thereafter use the frozen surface as a roadbed without any type of reinforcement. In these same climates ice is also used to re-surface roads that are in poor driving condition. 
         [0004]    The use of natural ice for the road surface and support is subject to weather conditions and the inherent strength of the ice created from only frozen water. These ice roads are unreliable and of unknown strength. Further they require the truck and other means of transport to proceed at slow speeds, because the natural ice will bend forming a wave in front of the truck. As the trucks speed increase this wave grows and eventually caused the ice to crack. Also the trucks weight must be restricted to prevent the ice from cracking. 
         [0005]    The use of natural ice results in the natural ice melting at temperatures above freezing. 
         [0006]    Therefore, improvements in the strength of the ice roads and making the ice roads more resistant to thawing would be beneficial and to the businesses that require their products, materials and supplies to be shipped over the ice roads, and in addition will improve the safety of the vehicle drivers 
       SUMMARY OF THE INVENTION  
       [0007]    The present invention provides a method of fabricating ice roads using wood pulp mixed with water or re-surfacing roads in cold climates. Additional features of the invention will be described hereinafter that form the subject of the claims of the invention. Those skilled in the art should appreciate that they can readily use the disclosed conception and specific embodiment as a basis for designing or modifying other structures for carrying out the same purposes of the present invention. Those skilled in the art should also realize that such equivalent constructions do not depart from the spirit and scope of the invention. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS  
         [0008]    For a more complete understanding of the present invention, reference is now made to the following descriptions taken in conjunction with the accompanying drawings, in which: 
           [0009]      FIG. 1  illustrates a diagram of an embodiment of ice road constructed according to the principles of the present invention; and 
           [0010]      FIG. 2  illustrates a flow diagram of an embodiment of a method of fabricating an ice road carried out according to the principles of the present invention. 
       
    
    
     DETAILED DESCRIPTION  
       [0011]    The present invention provides a roadway that utilizes wood pulp embedded in frozen water or ice to form a composite structure. Wood pulp is used in the composite structure of the ice to assist in creating a surface with a higher compressive and tensile strength and to assist in dispersing the weight of the vehicles over a greater area. The wood pulp is in suspension in the ice to form the composite structure. The composite ice is a much stronger structure than natural ice. Research has shown that natural ice has a modulus of around 22.5 kg/cm 2  but since natural ice is very inconsistent its modulus could be as low as 5 kg/cm 2 . Where as the composite ice has a modulus that is much more consistent, that is much less variability in its strength. Its modulus is 25% higher than natural ice. Typical composites will have a modulus of 77 kg/cm 2 . Thus, the composite structure is more capable of carrying greater weight before failure. 
         [0012]    The composite structure is also much more ductile then natural ice and has been shown to be able to withstand high velocity rifle shots without shattering. The composite ice is also 4 to 5 times stronger than natural ice in tension. 
         [0013]    Additionally, the addition of the wood pulp to the ice makes the ice more resistant to thawing because of its insulating properties. 
         [0014]    The composite structure possesses properties that would allow you to build a roadway that for a given thickness could support a heavier load, withstand vehicles being driven at higher speeds and would last longer than the natural ice as the temperature rose above freezing. 
         [0015]    Also, given the fact that the composite is more consistent than natural ice, the thickness of the composite ice does not need to be as thick as natural ice to ensure the safe transport of materials across the roadway. The consistence of the composite ice reduces the cost of maintaining the roadway, since less testing and analysis has to be done to maintain the roadway. 
         [0016]    All of the advantages described above for making roads over frozen lakes also apply to using the composite ice approach to re-surface roads in poor conditions located in cold climates. 
         [0017]    Turning now to  FIG. 1 , illustrated is a diagram of an embodiment of the ice road surface, constructed according to the principles of the present invention. 
         [0018]    Once the lake  100  has frozen to the point that the natural ice  110  will support light construction equipment the construction of the composite roadway can begin. First barriers  120  must be built on each side of the roadway that will be filled with the materials used to create the composite ice road. These barriers  120  can be built using naturally available materials such as snow, or manmade materials such as plastic tubes that can be filled with water. 
         [0019]    Once the barriers  120  are in place, the mixture of water and wood pulp  130  is put between the barriers and allowed to freeze. The mixture is 14 percent wood pulp to water based upon volume. The mixture can either be pumped or sprayed in place. If additional strength members  140  are needed to support the roadway load then only part of the water and wood pulp mixture  130  is added and allowed to freeze and then the strength members  140  are added to the roadway. The additional strength members can consist of cables laid along the direction of traffic on the roadway or netting added to the road way. These cables or netting can be made of metal, synthetic or natural fibers. The choice of material will depend upon the strength needed and the cost of the materials. The remaining mixture of water and wood pulp  130  is then added to the roadway. 
         [0020]    Once the roadway freezes, water based, colored dye  150  is placed over the roadway and allowed to freeze. Then another layer of composite ice mixture  130  is placed on the roadway. This represents the wear surface for the roadway. Any time the colored dye is exposed, the road maintenance crews will know that another layer of composite ice needs to be added to the roadway to ensure that the roadway is safe. 
         [0021]    On top of this top road surface, a traction layer  160  can be added to the roadway to improve the vehicles traction. This traction surface  160  can consist of a mixture of water and gravel. The percent of gravel that is added is a function of how much traction is required and what size gravel is used. 
         [0022]      FIG. 2  illustrates a flow diagram of a method of fabricating an ice road carried out according to the principles of the present invention. This block diagram lays out the step by step procedures for building a composite ice roadway. 
         [0023]    The procedure begins in step  210 . After the lake has frozen  220  enough to support light construction equipment, construction of the road can begin. The composite road surface is built over this natural ice base. 
         [0024]    The roadway is then laid out  230  and the barriers that will hold the composite ice are constructed. Once the barriers are in place the mixture of water and wood pulp is added between the barriers  240 . If the design of the roadway requires the inclusion of additional strength members  250 , they are added at this time. Then another layer of composite ice  260  is added to the roadway. 
         [0025]    At this point the roadway would be ready for traffic, but additional features such as a safety warning layer and a traction layer can be added. 
         [0026]    After the basic roadway is formed a safety color layer is placed on the roadway. Then a wear layer of composite ice  280  is added to the roadway. Once this layer has frozen, a traction layer  290  can be added to the roadway. 
         [0027]    Although the present invention has been described in detail, those skilled in the art should understand that they can make various changes, substitutions and alterations herein without departing from the spirit and scope of the invention in its broadest form.