Abstract:
Disclosed is a method, process and system for sealing cracks in concrete substrates such as walls and floors. A plurality of holes are drilled through the concrete substrate, with at least one hole on each opposing side of the crack. Then a polymer rubber gel that is thick enough to not flow at room temperature (e.g. comprising 99% solids) is heated in a tank to an elevated temperature (e.g. 120-200° F.). Next, the heated polymer rubber gel is pumped in the heated state through one of the holes in the concrete. The pumping continues until the polymer rubber gel is observed exiting a second drilled hole that is spaced apart from the injecting hole. The polymer rubber gel rapidly cools and solidifies, thereby forming a waterproofing membrane that seals the crack(s).

Description:
PRIORITY 
       [0001]    This application claims the priority benefit of U.S. Provisional Application No. 62/159,207 filed on May 8, 2015, which is hereby incorporated herein by reference in its entirety. 
     
    
     FIELD 
       [0002]    The present invention relates generally to systems and methods for repairing water leaks in concrete substrates, such as in walls and floors. 
       BACKGROUND 
       [0003]    Concrete is widely used to form building structures such as walls and floors. When these concrete building structures are below grade, they are susceptible to water infiltration. Water seeks to penetrate via a path of least resistance, so cracks in the concrete wall or floor provide an easy path for water to penetrate and reach the interior space of the structure. 
         [0004]    Attempts have been made to patch cracks in concrete with mortar or the like, but the patch material is difficult to apply due to the presence of water in the location to be patched. Thus, the patch is susceptible to failure. 
         [0005]    Other known solutions are to drill holes in the concrete substrate and inject mud, concrete or a chemical grout under pressure in order to cause the material to flow behind the substrate and hopefully seal the crack(s). One injected chemical grout attempted is a room-temperature flowable polymer rubber gel with the brand name TURBOSEAL. This material is composed of approximately 78% solids, so it will flow at room temperature. These methods have had some measure of success, but there is a continuing need to find even better solutions to seal concrete cracks. 
       SUMMARY 
       [0006]    The present invention provides a method and system for sealing cracks in concrete substrates such as walls and floors. A plurality of holes are drilled through the concrete substrate, with at least one hole on each opposing side of the crack. Then a polymer rubber gel that is thick enough that it does not flow at room temperature (e.g. comprising 99% solids) is heated in a tank to an elevated temperature (e.g. 120-200° F.). Next, the heated polymer rubber gel is pumped in the heated state through one of the holes in the concrete. The pumping continues until the polymer rubber gel is observed exiting a second drilled hole that is spaced apart from the injecting hole. The polymer rubber gel rapidly cools and solidifies, thereby forming a waterproofing membrane that seals the crack(s). 
         [0007]    The disclosure includes a method of providing a restorative waterproofing membrane to a distal side of a concrete substrate that includes a crack through the substrate from a proximal side to the distal side. The method includes forming a first hole through the concrete substrate from the proximal side that communicates with the distal side. A second hole is formed through the concrete substrate from the proximal side that communicates with the distal side. The second hole is laterally displaced from the first hole along the proximal side such that the crack lies between the first hole and the second hole. An injection valve is coupled to the first hole. A distal end of a heated hose is coupled to the injection valve. A proximal end of the heated hose is coupled to a heated hopper. The heated hopper includes a pump. A polymer rubber gel material is introduced into the heated hopper. The temperature of the polymer rubber gel in the hopper is elevated until the polymer rubber gel material can flow under pressure through the heated hose. The polymer rubber gel material is pumped at the elevated temperature through the injection valve until the polymer rubber gel material can be observed exiting the second hole. 
         [0008]    The disclosure also includes a process for repairing a water leak through a concrete substrate. The method includes forming a first hole through the concrete substrate from the proximal side that communicates with the distal side. A second hole is formed through the concrete substrate from the proximal side that communicates with the distal side. The second hole is laterally displaced from the first hole. A polymer rubber gel material is pumped at an elevated temperature through the first hole until the polymer rubber gel material can be observed exiting the second hole. The polymer rubber gel is sufficiently viscous that the polymer rubber gel cannot be pumped when at room temperature. 
         [0009]    The disclosure further includes a system for repairing a water leak through a concrete substrate. The system includes an injection valve, a polymer rubber gel material that comprises 99% solids, a heated tank configured to heat the polymer rubber gel material to a temperature range of 120-200° F., a pump coupled to the heated hopper and a heated delivery hose coupled to the hopper. An end of the heated delivery hose is configured to couple to an end of the injection valve. 
         [0010]    The above summary is not intended to limit the scope of the invention, or describe each embodiment, aspect, implementation, feature or advantage of the invention. The detailed technology and preferred embodiments for the subject invention are described in the following paragraphs accompanying the appended drawings for people skilled in this field to well appreciate the features of the claimed invention. It is understood that the features mentioned hereinbefore and those to be commented on hereinafter may be used not only in the specified combinations, but also in other combinations or in isolation, without departing from the scope of the present invention. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]      FIG. 1  is a schematic perspective cross-sectional view of a restorative waterproofing system according to certain example embodiments. 
           [0012]      FIG. 2  is a schematic side cross-sectional view of a restorative waterproofing system according to certain example embodiments. 
           [0013]      FIG. 3  is an image of a portion of a concrete floor having received a restorative waterproofing membrane according to certain example embodiments. 
           [0014]      FIG. 4  is an image of a portion of a concrete wall having received a restorative waterproofing membrane according to certain example embodiments. 
       
    
    
       [0015]    While the invention is amenable to various modifications and alternative forms, specifics thereof have been shown by way of example in the drawings and will be described in detail. It should be understood, however, that the intention is not to limit the invention to the particular example embodiments described. On the contrary, the invention is to cover all modifications, equivalents, and alternatives falling within the scope of the invention as defined by the appended claims. 
       DETAILED DESCRIPTION 
       [0016]    In the following descriptions, the present invention will be explained with reference to various exemplary embodiments. Nevertheless, these embodiments are not intended to limit the present invention to any specific example, environment, application, or particular implementation described herein. Therefore, descriptions of these example embodiments are only provided for purpose of illustration rather than to limit the present invention. 
         [0017]    Referring to  FIG. 1 , the hot injection concrete repair system is shown according to one example embodiment. The system is used to provide a restorative waterproofing membrane that seals cracks in the concrete where the injected material is applied or flows. In this embodiment, the system is being applied to a below-grade concrete wall. However, it should be recognized that the present system can be applied to any concrete or masonry substrate in any orientation or location. 
         [0018]    The concrete wall substrate  100  shown in  FIG. 1  functions to retain soil  102  and define an interior space of a structure. The concrete substrate can be a retaining wall, a basement wall, a tunnel wall or any other concrete structure that retains earth. The concrete substrate can be formed as a poured concrete, one or more precast segments, dry cast blocks (e.g. segmental wall blocks or grey block), brick and mortar, or any other structure that is intended to retain earth. 
         [0019]    The present system and method can be applied to repair one or more cracks in the concrete wall  100  or the membrane can be established prophylactically to guard against leakage through future cracks that may form in the concrete wall  100 . 
         [0020]    Another way that a concrete wall  100  can fail and leak is where the protective layer(s) between the wall and the soil are compromised. For example, between the concrete substrate  100  and the soil  102  is a sandwich of a protective layer  104  and waterproofing material  106 . If the waterproofing sandwich  104 ,  106  is compromised or is inadequate to prevent water passage from the soil to the concrete substrate  100 , there is a substantial chance that water will penetrate through the concrete wall  100 . The penetration will be even worse where the concrete wall  100  is cracked as the water will attempt to escape into the interior through the crack(s). 
         [0021]    In order to remedy the water intrusion, a series or array of holes  101  are drilled through the concrete wall  100  as shown in  FIG. 1 . Preferably multiple holes  101  are drilled. At least one hole is formed on each side of the crack to be sealed. This allows flow of the chemical grout (polymer rubber gel) through a first hole (via an injection valve  110 ) to be monitored to ensure that the grout flows over the crack across the back side (soil facing side) of the wall  100 . If the crack runs vertical, then it is particularly advantageous to have a water exit hole  112  vertically below the hole where the grout is being injected. This is because the injection volume will displace water located behind the wall and that water needs somewhere to go so that it does not form pockets within the grout region. 
         [0022]    As shown in  FIG. 1 , a volume of polymer rubber gel  108  is injected through the holes  101  made in the wall  101  to form a sealed region behind the wall  100  between the concrete and the existing insulation  106  or protective layer  104 . 
         [0023]    The chemical grout in one embodiment can be a polymer rubber gel material  108 . In particular, it is preferred that the polymer rubber gel comprises a sufficient solids percentage such that it is not flowable at room temperature. Most preferably, the polymer rubber gel comprises 99% solids. 
         [0024]    Polymer rubber gel is a non-curing rubber emulsion with adhesive and cohesive physical characteristics. Polymer rubber gel never completely cures and remains in a flexible state. Since it never cures, it is capable of self-healing under application of hydrostatic pressure. Also, due to Polymer rubber gel&#39;s responsiveness to substrate movement and vibration, it makes for an excellent substance to repair cracks in concrete and/or separations in waterproofing layers. 
         [0025]    In contrast, other chemical grouts cure and crack, leading to renewed water intrusion. The non-curing property of polymer rubber gel can weather the constant stress of thermal expansion/contraction, seismic activity and vibration that might be experienced in a wide variety of applications. The polymer rubber gel layer  108  also provides for creation of a seamless or continuous layer. Thus, there are no seams or gaps where water can easily penetrate. 
         [0026]    Not all polymer rubber gels are the same. For example, different gels have widely differing amounts of solids in their content. Thus, any two given gels will have very different material properties. The higher the solids content, the more viscous the polymer rubber gel material will be at room temperature. 
         [0027]    To achieve flowability (and injectability) at room temperature, a relatively thin gel such as TURBOSEAL has been conventionally used. TURBOSEAL polymer rubber gel is approximately 78% solids and can flow at room temperature. This allows the gel to be injected at typical room temperature and up to about 90° F. But such gel cannot be heated to an elevated temperature without the gel breaking down. As a result, only a modest waterproofing membrane can be formed behind the concrete wall  100 . Also, the room temperature flowability means that the injected polymer rubber gel material can migrate over time, which may cause the water leakage to reoccur. 
         [0028]    In contrast, the present invention utilizes a polymer rubber gel with a much higher solids content than TURBOSEAL polymer rubber gel and the like. The preferred gel material is not flowable at room temperature (e.g. 99% solids). That also means it is not injectable at room temperature. 
         [0029]    One example polymer rubber gel can have the physical properties noted in the following Table 1: 
         [0000]    
       
         
               
               
             
           
               
                 TABLE 1 
               
               
                   
               
             
             
               
                 Solids Content 
                 99% (ASTM D 1353) 
               
               
                 Resistance to Decay 
                 0% moisture permeation &amp; weight 
               
               
                   
                 change (ASTM E 154-88) 
               
               
                 Hardness 
                 80 (ASTM C836-89) 
               
               
                 Puncture Resistance 
                 102 lbf (ASTM E-154) 
               
               
                 Flash Point 
                 &gt;228° C. (ASTM D56) 
               
               
                 Tensile Strength 
                 190 +/− 0.11 lbf (ASTM D-412-98) 
               
               
                 Elongation % 
                 394% (ASTM C1135) 
               
               
                 Hydrostatic Pressure Resistance 
                 169 3 lbf/in2 (ASTM D-751) 
               
               
                 Adhesion to Concrete 
                 Rating of 1—Excellent (ASTM D- 
               
               
                   
                 412-98) 
               
               
                 Crack Bridging Flexibility 
                 No cracks (ASTM C-836-89) 
               
               
                 Moisture Permeability 
                 0.0185 perms (ASTM E-96-80) 
               
               
                 Peel Resistance 
                 1.01 lbf/in (ASTM D1876-08) 
               
               
                   
               
             
          
         
       
     
         [0030]    In order to address the need for the preferred polymer rubber gel material to be flowable in order to be injected, the invention includes heating of the polymer rubber gel to an elevated temperature range of 120-200° F. and most preferably 150-200° F. The preferred polymer rubber gel does not break down because it is almost entirely solids. 
         [0031]    The heating of the polymer rubber gel can be accomplished by providing a heated hopper  114  or tank where the solid blocks of gel material are deposited after removing them from their packaging. The hopper  114  then heats the solid blocks to lower the viscosity of the polymer rubber gel, which allows it to flow. 
         [0032]    A heated hose  116  is coupled to the hopper  114  to be a conduit between the hopper  114  and the injection valve  110 . The heated hose  116  helps maintain the elevated temperature of the polymer rubber gel until it reaches the point of injection because the polymer rubber gel will quickly cool upon injection. 
         [0033]    An injection pump  118  is provided to the hopper  114  to pressurize the flow of heated polymer rubber gel from the hopper  114  and through the hose  116  so that the polymer rubber gel can be injected through the valve  110  with pressure. The flow of the heated polymer rubber gel can be regulated by operation of the injection valve  110 . 
         [0034]    Arrows are provided in  FIG. 1  to indicate the direction of gel material flow during an injection process. 
         [0035]    In use, the injection valve  110  is inserted into a first hole  101  on a first side of a crack. The hose  116  is attached to the injection valve  110 . The heated polymer rubber gel is pumped under pressure through the injection valve which causes the polymer rubber gel to flow along the back side of the concrete wall  100 . Once the polymer rubber gel begins to exit the second hole in the concrete wall located on an opposite side of the crack, the injection valve is closed to stop the material flow. This process can be repeated for additional spaced-apart holes until a desired restorative membrane is formed behind the wall (soil side). 
         [0036]    After injection, the polymer rubber gel material  108  flows for a short time until it cools back to ambient temperature, which effectively solidifies the polymer rubber gel so that it cannot flow or migrate further. This solidification property at room temperature provides a far stronger water barrier and seal as compared to use of the room temperature flowable gel material. Moreover, the higher solids content of the invention combined with heating allows for better spreading and filling of cracks since the heated polymer rubber gel is less viscous at the elevated temperature as compared to the prior art polymer rubber gel at room temperature. Thus, a stronger final sealing effect can be achieved as compared to the use of room temperature flowable gel material. The increased flowability due to elevated material temperatures of the invention also makes for a quicker restoration process because the heated gel material flows quicker than the room temperature flowable gel material. The self-healing ability of the polymer rubber gel of the invention and its non-migration characteristics can also provide a permanent repair in many applications. 
         [0037]    A waterproofing method can include injecting the heated polymer rubber gel material in more than one hole  101  separately, or simultaneously. The number of injection holes or sites employed depends on the size of the area needing to receive the restorative waterproofing membrane. 
         [0038]      FIG. 2  illustrates the present invention as being applied to a concrete floor slab embodiment of a concrete substrate  100 . As with the vertical wall, a plurality of holes  101  are drilled through the substrate so that the injected polymer rubber gel material  108  can reach behind the slab. One hole receives the injection valve  110  and a hole on an opposite side of a crack is monitored for the injected polymer rubber gel material to appear, which indicates that the polymer rubber gel  108  has spread at least to such radius. The plurality of holes can include at least one water escape hole  112  so that water pockets do not form within the restorative membrane. The same hopper  114  and hose  116  are used as in the wall embodiment, and the same material  108  and elevated temperature are employed. 
         [0039]      FIG. 3  illustrates an injection valve  110  in a first hole  101   a  drilled into a concrete floor substrate  100 . A second hole  101   b  is spaced away from the injection site  101   a  and is showing the polymer rubber gel material  108  having slightly exited the hole  101   b . This showing at the second hole  101   b  indicates that the polymer rubber gel  108  has spread behind the substrate  100  at least as far as the monitoring/water exit hole  101   b.    
         [0040]      FIG. 4  illustrates an injection valve  110  disposed in an injection hole  101  in a concrete wall substrate  100 . Note that the delivery hose has been removed. Some of the polymer rubber gel  108  that was in the valve  110  upstream of the shutoff is shown oozing from the valve opening since the gel  108  is still sufficiently heated to slightly flow. 
         [0041]    While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiments, it will be apparent to those of ordinary skill in the art that the invention is not to be limited to the disclosed embodiments. It will be readily apparent to those of ordinary skill in the art that many modifications and equivalent arrangements can be made thereof without departing from the spirit and scope of the present disclosure, such scope to be accorded the broadest interpretation of the appended claims so as to encompass all equivalent structures and products. Moreover, features or aspects of various example embodiments may be mixed and matched (even if such combination is not explicitly described herein) without departing from the scope of the invention.