Patent Publication Number: US-2002001506-A1

Title: Method of resurfacing roads and bridge decks

Description:
SUMMARY OF THE INVENTION  
       [0001] The invention relates to the field of road surface repair and in particular the repair of concrete bridge decks.  
       BACKGROUND OF THE INVENTION  
       [0002] It is a common occurrence for roads to become worn due to traffic. Wearing of roads can cause the concrete and asphalt road surfaces to become smooth and slick. Asphalt road surfaces can become rutted due to the combination of high temperatures and heavy trucks. These factors cause unsafe driving conditions. Other factors such as oil or other fluids leaking from vehicles can also create slick surfaces even when the smooth surfaces are otherwise dry. Concrete bridge decks also are subject to transverse cracking which allows water to seep in and corrode the steel reinforcing within the concrete bridge deck. Spalling is another defect in concrete bridge decks which causes the surface of the concrete to crumble leaving the aggregate exposed.  
       [0003] Resurfacing of worn bridge decks has utilized various methods. One expensive and time consuming method includes shot blasting the top portion of the concrete pavement to create high friction surface. This procedure involved causes damage to the concrete. Another repair method is the application of a thin coating of epoxy resin mixed with aggregate. Neither method is effective in filling in ruts or potholes or cracks.  
       [0004] Prior methods of road resurfacing and bridge deck repair are not as readily adaptable to providing added improvements to the pavement such as anti-ponding lines or ice preventing devices.  
       [0005] In view of the forgoing it can be seen that there is a need for a new method of road surface repair that is suitable for use in repair of bridge decks that avoids long traffic delays and provides a long lasting repair.  
       OBJECTS AND SUMMARY  
       [0006] One object of the invention is to provide a bridge deck resurfacing material formed of a layer or layers of cementitious material and rock chips to provide a long lasting and high friction surface.  
       [0007] Another object of the invention is to provide a method of applying the materials to the road surface quickly to avoid long traffic delays.  
       [0008] Yet another object of the invention is to provide a method of filling in potholes prior to resurfacing the road.  
       [0009] Still another object of the invention is to provide a high friction road surface.  
       [0010] Yet another object of the invention is to provide anti-ponding lines in the road surface.  
       [0011] Another object of the invention is to provide anti-icing devices embedded in the road surface.  
       [0012] In summary, this invention is directed to the resurfacing of roads and in particular bridge decks. The invention includes spreading with a squeegee a thin layer of polymer modified concrete over a bridge deck surface and then applying by broadcasting a layer of granite rock chips to the wet concrete to provide a high friction surface. An optional second layer of the polymer modified concrete is then applied over the first layer of rock chips using the squeegee and an optional second layer of rock chips is then broadcast over that layer and then heavy quartz sand may be applied. If spalling or potholes are present in the road surface, these defects are repaired prior to the road resurfacing. Repair of potholes is accomplished by mixing granite aggregate rock chips with polymer modified concrete to form a putty which is then screeded into the potholes.  
       [0013] Other improvements can be added to the bridge deck during the resurfacing process such as anti-ponding lines to facilitate runoff of water from the road surface and reduce hydroplaning. The lines create a series of grooves in the pavement surface extending from the centerline to the edge of the road perpendicular to the direction of travel.  
       [0014] De-icing devices may also be added during the resurfacing project to prevent snow and ice from building up on the road surface. Electric resistance heating elements are placed on the highway surface and covered with polymer modified concrete. The heating elements are preferably connected to solar cells and/or batteries or an electric generator to provide electricity to heat the road surface to sufficient temperature to prevent ice and snow from accumulating on the heated road surface. 
     
    
    
     [0015] Other objects, uses and advantages will be apparent from a reading of this description which proceeds with reference to the accompanying drawings forming a part thereof.  
     BRIEF DESCRIPTION OF THE DRAWINGS  
     [0016]FIG. 1 is a perspective view of a bridge deck in need of repair.  
     [0017]FIG. 2 is a view of the bridge deck of FIG. 1 having potholes, spalling and cracks repaired prior to application of the resurfacing material.  
     [0018]FIG. 3 shows the application of the polymer modified cement to the bridge deck;  
     [0019] FIGS.  4 - 7  show the repair of a road surface in sequential cross-sections.  
     [0020]FIG. 8 shows a bridge deck having sections broken away to reveal layers.  
     [0021]FIG. 9 shows a bridge deck having heating wires placed in the wheel lanes prior to application of the resurfacing materials. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION  
     [0022]FIG. 1 shows a bridge deck  10  having defects  12  therein. Prior to resurfacing the bridge deck  10  these defects  12  (i.e. potholes, spalling, transverse cracks or popouts, etc.) must first be repaired. This is accomplished by filling in the defects with a mixture of polymer modified concrete and rock chips. The polymer modified concrete is preferably made by mixing  330  resin manufactured by Rohm &amp; Haas with Quik Krete cement powder at a ratio of two gallons of resin per sixty pound bag of powder. The rock chips are preferably granite chips in sieve size “0” (¼″×⅛″) and in the defect repair portion of the bridge deck resurfacing project are mixed with the Quik Krete and resin to form a putty  14  and screeded into the defects  12  to form a level road surface  16  as shown in FIG. 2. The rock chip and resin mixture is then allowed to set up. The time to set up will vary depending on weather conditions, but will generally be less than an hour.  
     [0023] Next the polymer modified concrete  18  is applied to the road surface  16  of the bridge deck  10  as shown in FIG. 3. The polymer modified concrete layer  18  is applied to the road surface  16  using a squeegee machine  20  such as that described in my prior U.S. Pat. No. 5,735,952. The squeegee machine  20  preferably uses a  12  foot wide squeegee  22  as shown which can cover an entire traffic lane in one pass with a thin coating of ⅛ inches to {fraction (1/16)} inches of polymer modified concrete.  
     [0024] Still looking at FIG. 3, a layer of rock chips  24  is applied while the polymer modified concrete layer  18  is still wet. The rock chips  24  are applied by broadcasting using an air blower  26  giving the rock chips  24  enough velocity to embed into the polymer modified concrete layer  18 . The rock chips  24  are preferably applied by using a blower on the shoulder lane next to the lane on which the polymer modified concrete layer  18  has been laid and blowing the rock chips  24  onto the polymer modified concrete layer  18 . The polymer modified concrete layer  18  is then allowed to dry. This period may vary according to weather conditions, but generally is about  1  and ½ to 2 hours. Any loose rock chips are then blown off by an air blower  27 .  
     [0025] FIGS.  4 - 7  show sequential cross-sections of the road surface  16  as first the putty  14  is applied, then the polymer modified concrete layer  18  and finally the rock chips  24 .  
     [0026]FIG. 8 shows a completed bridge deck resurfacing with portions broken away to reveal the layers  18 ,  24 ,  28  and  30  of resurfacing material. A second layer of polymer modified concrete  28  is applied over the first layer of rock chips  24 . The second layer of polymer modified concrete  28  is of the same thickness as the first layer  18 . Next a second layer of rock chips and optionally heavy quartz sand  30  is applied to the second layer of polymer modified concrete  28  using the blower technique described above.  
     [0027] The process is repeated for each travel lane until the entire bridge deck  10  is resurfaced. The resurfaced lanes can be driven on in about 1 ½ to 2 hours, but the polymer modified concrete layers  18  and  28  will continue to cure for about seven days.  
     [0028] Referring now to FIG. 9, resurfacing bridge decks in this manner provides an ideal opportunity to install de-icing devices in the pavement  32 . Prior to my invention applications of de-icing devices could be installed only as part of new construction. Now, with my invention, de-icing devices may be installed on existing bridge decks and road surfaces.  
     [0029] As shown in FIG. 6, heating elements  34 , preferably in the form of copper wires of sufficient diameter to be durable and produce heat to warm the pavement  32  enough to melt ice and snow are placed on the wheel lanes  36  of the pavement  32  after application of the first polymer modified concrete layer  38 . Layer  38  is shown as applied in three foot wide stripes covering the wheel lanes  36  of the pavement  32 . However, it should be understood that the first layer  38  could cover the entire lane and the heating elements  34  could also be applied across the whole lane. The heating elements  34  are preferably laid in a grid pattern as shown in FIG. 6, but could also be placed in a zigzag pattern. Preferably, power is provided to the copper wires by batteries  40  and photovoltaic solar cells  42 . However, power could also be provided by conventional power lines or a generator (both not shown). A thermostat may be applied to the heating elements  34  to maintain a desired temperature of the road surface during sub-freezing weather. Preferably, the thermostat would be set at a temperature of about 40 degrees Fahrenheit so that the heating elements  34  will be activated when the surface temperature dips below 40 degrees.  
     [0030] After the heating elements  34  are installed and first polymer modified concrete layer  38  is allowed to dry, a second layer of polymer modified concrete  44  is applied over the entire wheel lane  36  covering the heating elements  34 . Layer  44  may also be applied to the entire road surface. Then a layer  46  of rock chips and heavy sand is broadcast by blowing onto the polymer modified concrete layer  44  to embed the rock chips and sand into the top of the wet concrete. The concrete layer  44  is allowed to dry prior to traffic being allowed to travel over the roadway.  
     [0031]FIG. 3 also shows the application of anti-ponding lines  48  to the polymer modified concrete layer  18 . The anti-ponding lines  48  are formed in the polymer modified concrete layer  18  immediately after the application of the layer  24  of rock chips is broadcast onto the polymer modified concrete layer  18  but while the polymer modified cement  18  is still wet. The polymer modified concrete layer  18  is preferably one-eighth to one -quarter inches in thickness which will facilitate deeper lines  48 . The lines  48  are formed simply by drawing a rake  50  across the travel lane  52  to provide evenly spaced lines  48  perpendicular to the direction of travel. The lines  48  create parallel shallow grooves  54  spaced approximately three-fourths of an inch to one inch apart which facilitate water flow off the bridge deck  16  and helps prevent ponding.  
     [0032] While this invention has been described as having a preferred design, it is understood that it is capable of further modifications, uses and/or adaptations of the invention following in general the principle of the invention and including such departures from the present disclosure as come within the known or customary practice in the art to which the invention pertains and as maybe applied to the central features hereinbefore set forth, and fall within the scope of the invention and the limits of the appended claims.