Methods and formulations for sealing structural leaks

Abstract

A method for sealing a leaking crack in a structure includes drilling a delivery channel into the structure adjacent to the crack, flowing toward and into the crack. A delivery nozzle is inserted into the delivery channel, and a sealant containing latex and water is injected into the crack under pressure. The sealant is injected until it forms a weep on the outer surface of the crack, and may be sprayed with a reactive agent to cure the sealant and form a film. Additional sealant may then be injected through the delivery channel after the film has formed to enhance penetration of the sealant into the crack.

Description

[Technical Field]

[0001] The present invention relates generally to methods and formulations for sealing structural leaks. [Background technology]

[0002] Structural leaks are traditionally sealed by injecting polyurethane foam, however polyurethane has poor durability, deteriorates in salt water, and is difficult to apply.

[0003] Latex-based sealing compositions have been proposed, including by WO 2019 / 169423 (RELBORGN PTY ​​LTD. AND TRIOMVIRI PTY LTD) dated September 12, 2019, which describes a variety of mining to civil engineering sealing applications for structures that may include tunnel repair or the formation of containment barriers for spills or waste storage facilities.

[0004] The present invention seeks to provide a way to overcome or substantially ameliorate at least some of the deficiencies of the prior art, or at least to provide an alternative.

[0005] Where any prior art information is referred to herein, it should be understood that such reference is not an admission that the information forms part of the common general knowledge in the art in Australia or anywhere else. Summary of the Invention

[0006] Provided herein is a method for sealing leaking cracks in a structure using a latex-based sealant that is subsequently cured with a reactive agent, thereby providing a durable seal, including a seal that is resistant to salt water. The method for sealing structural leaks according to the invention is outlined by claim 1. Further features are outlined by the dependent claims.

[0007] The method comprises the steps of drilling a delivery channel into the structure adjacent the crack and drilling the delivery channel toward the crack until it meets the crack.

[0008] A delivery nozzle, such as an injection packer, is then inserted into the delivery channel and a sealant containing latex and water is injected under pressure through the delivery nozzle into the crack.

[0009] The sealant is injected until it forms a weep on the outer surface of the crack, after which a reactive agent is sprayed onto the weep, such as with a spray gun, to cure the sealant over the entire surface of the crack and form a film over the entire outer surface of the crack.

[0010] Additional sealant is then injected through the delivery channels after the coating has formed, and may be injected at high pressures, such as above 500 psi.

[0011] The coating forms an outer barrier that holds the sealant further injected into the crack under pressure, thereby enhancing penetration of the sealant throughout the crack.

[0012] A reactive agent may be further injected through the delivery nozzle to cure the sealant within the crack, and further delivery channels may be drilled along the length of the crack for further application of the sealant.

[0013] Our trials and experiments have shown that the sealant may initially have a pH of about 10 or above, and that once the reactive agent is applied, the pH is lowered, preferably to about 7-7.5, resulting in optimal sealant properties.

[0014] The formulation of the reactive agent may be selected depending on the pH of the water seeping through the crack. If the pH is less than 7, which is typically a groundwater leak, typically freshwater, the first formulation of the reactive agent may contain sodium chloride, which may be varied depending on the pH range of the water. Conversely, if the pH is greater than 7, which is typically a saltwater leak, the second formulation of the reactive agent may contain calcium chloride, which may be varied based on the measured pH of the leaking water.

[0015] An injection packer may be used to inject the sealant, which includes interchangeable sleeves of different diameters to match the diameter of the delivery channel. The injection packer is designed so that there is no need to drain the pump or delivery hose between applications, thereby eliminating product waste and maximizing time spent on the task.

[0016] As such, with the foregoing in mind, and according to an embodiment, there is provided a method of sealing a leaking crack in a structure, the method comprising the steps of: drilling a delivery channel in the structure adjacent to the crack toward and into the crack; inserting a delivery nozzle into the delivery channel and injecting a sealant comprising latex and water into the crack under pressure through the delivery nozzle; injecting the sealant until it forms a weep on an outer surface of the crack; spraying a reactive agent into the weep to cure the sealant over the entire surface of the crack and form a coating over the entire outer surface of the crack; and injecting additional sealant through the delivery channel after the coating is formed.

[0017] The step of injecting additional sealant may further include increasing the pressure of the sealant after the coating is formed.

[0018] The pressure may be increased to greater than 500 psi.

[0019] The pressure may be increased to less than 2500 psi.

[0020] The method may further comprise injecting a reactive agent through the delivery channel to cure the sealant within the crack.

[0021] The reactive agent may be injected after the coating is formed.

[0022] The method may further comprise drilling an additional delivery channel along the length of the crack and injecting additional sealant through the additional delivery channel.

[0023] The method may include using an injection packer comprising a delivery conduit, a small diameter sleeve slidable over the delivery conduit, and a large diameter sleeve slidable over the small diameter sleeve, and the method may include retaining or removing the large diameter sleeve based on a diameter of the delivery channel.

[0024] The injection packer may further include a large diameter distal collar and a small diameter distal collar attachable to the distal end of the delivery conduit, and the method may include attaching the large diameter distal collar to the large diameter sleeve.

[0025] The method may include using an injection packer comprising a proximal annulus, an inner conduit, and a collar attachable to a distal end of the inner conduit, the proximal annulus and the distal collar each being supported on either end of an outer sleeve, and the method may include tightening the proximal annulus to bear the weight of the outer sleeve on the distal collar, causing the distal collar to expand within the delivery conduit.

[0026] The sealant may include a ratio of latex and water of about 3:2.

[0027] The method may further include a base that maintains the pH of the sealant above 7.5 prior to application.

[0028] The base may maintain the pH of the sealant at a pH greater than 10.

[0029] The base may comprise a weak base.

[0030] The base may comprise ammonia.

[0031] One liter of sealant may contain about 600 mL of latex, about 398 ml of water, and about 2 mL of ammonia.

[0032] The water may have a neutral pH.

[0033] The reactive agent may be formulated to lower the pH of the sealant to 7-8.

[0034] The reactive agent may be formulated to lower the pH of the sealant to about 7 to 7.5.

[0035] The method may comprise selecting a formulation of the reactive agent depending on the pH of the reactive agent and the pH of water leaking through the crack.

[0036] The method may comprise a litmus test of water leaking through the crack before application.

[0037] If the pH of the water leaking through the crack is less than 7, a first formulation of reactive agent comprising water and sodium chloride may be selected.

[0038] The first formulation of reactive agent may comprise, for each liter it comprises, about 995 ml of water, about 3 mm of calcium chloride, and about 2 ml of sodium chloride.

[0039] The amount of sodium chloride may be varied depending on the pH of the water leaking through the crack.

[0040] For each liter comprising the first formulation of reactive agent, sodium chloride may be varied between 2 and 0 mL for a pH range of 6 to 6.8.

[0041] If the pH of the water leaking through the crack is greater than 7, a second formulation of reactive agent comprising water and calcium chloride may be selected.

[0042] The second formulation of reactive agent may comprise, for each liter it comprises, about 995 mL of water and about 5 mL of calcium chloride.

[0043] The amount of calcium chloride may be varied depending on the pH of the water leaking through the crack.

[0044] For each liter comprising the second formulation of reactive agent, calcium chloride may be varied between 0 and 6 ml for a pH range of 7.0 to 8.8.

[0045] The first formulation of reactive agent may be used on freshwater spills.

[0046] The second formulation of reactive agent may be used for saltwater leaks.

[0047] The delivery nozzle may have a diameter in the range of 10 mm to 50 mm.

[0048] The delivery channel may start between 50 and 75 mm from the crack.

[0049] The delivery channel may have a diameter of between 10 mm and 50 mm.

[0050] The delivery channel may extend at an angle of about 45 degrees.

[0051] The delivery channel may extend to a depth of 100-200mm.

[0052] According to a further aspect, there is provided a two-part formulation for sealing structural leaks, the formulation comprising a sealant comprising latex and water, a base that raises the pH of the sealant to above about 10, and a selection of reactive agent agents that, when applied to the sealant, lowers the pH of the sealant to about 7-7.5, the selection of reactive agent agents being selected from first and second reactive agent formulations depending on the pH of water seeping through the crack.

[0053] The first formulation may include water and sodium chloride.

[0054] The amount of sodium chloride can be varied between 2 and 0 mL for a pH range of 6 to 6.8 of the water seeping through the cracks.

[0055] The second formulation may include water and calcium chloride.

[0056] The amount of calcium chloride can be varied between 0 and 6 mL for a pH range of 7 to 8.8 of the water seeping through the cracks.

[0057] Other aspects of the invention are also disclosed. [Brief explanation of the drawings]

[0058] Notwithstanding other forms which may fall within the scope of the present invention, preferred embodiments of the present disclosure will now be described, by way of example only, with reference to the accompanying drawings in which:

[0059] [Figure 1] FIG. 1 illustrates sealing a leak crack in a structure according to one embodiment. [Figure 2] FIG. 2 illustrates sealing a leak crack in a structure according to one embodiment. [Figure 3] FIG. 3 illustrates sealing a leak crack in a structure according to one embodiment. [Figure 4] FIG. 4 illustrates sealing a leak crack in a structure according to one embodiment. [Figure 5]FIG. 5 illustrates sealing a leak crack in a structure according to one embodiment. [Figure 6] FIG. 6 illustrates sealing a leak crack in a structure according to one embodiment.

[0060] [Figure 7A] FIG. 7A shows one of two configurations of an injection packer according to one embodiment. [Figure 7B] FIG. 7B illustrates one of two configurations of the injection packer according to one embodiment.

[0061] [Figure 8] FIG. 8 illustrates steps in a method for sealing a leakage crack in a structure according to one embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0062] Referring to FIG. 8, a method 130 for sealing a leaking crack 101 in a structure 102 such as that shown in FIG. 1 may include determining the pH of water leaking from the crack 101 in step 117 for selection of an appropriate reactive agent 115 in step 118.

[0063] The method 130 comprises using a drill bit 130 to drill a delivery channel 104 near a leaking crack 101 in a structure 102, which is typically concrete, towards the crack 101 until the delivery channel 104 merges into it.

[0064] Typically, the delivery channel 104 may start between 50 and 75 mm from the crack 101, may have a diameter of 10 mm to 50 mm to accommodate an injection packer 105 as shown in Figure 7, and may extend at an angle of approximately 45° to a depth of 100 to 200 mm. Additional delivery channels 104 may be drilled along the length of the crack 101.

[0065] 3, in step 120, the delivery nozzle 131 of the injection packer 105 is inserted into the delivery channel 104. The delivery nozzle 131 may have a diameter selected for a desired flow rate of the sealant and may have an outer diameter in the range of 10 mm to 50 mm.

[0066] 7A and 7B illustrate an embodiment of a packer 105, and more particularly, how the packer 105 can be reconfigured to fit delivery channels 104 of various diameters.

[0067] Specifically, the delivery nozzle 131 may include an inner conduit 109 through which the sealant is injected into the delivery channel 104 and a replaceable outer sleeve 108 .

[0068] The packer 105 may further include distal retention collars 106, each fitting the outer diameter of a corresponding sleeve 108. Each retention collar 106 may include internal threads that engage with external threads on the distal end of the inner conduit 109. The retention collars 106 may be threaded onto and off the external threads of the inner delivery conduit by hand.

[0069] The delivery nozzle 131 may further include a distal expanding seal 135, such as rubber. While Figures 7A and 7B show the distal expanding seal 135 as being the same size, in embodiments, the packer 105 may include a similar expanding seal 135 with an outer diameter that fits the corresponding sleeve 108 and retaining collar 106.

[0070] The expanding seal 135 is compressed between the collar 106 and the sleeve 108 , causing the collar 106 to expand and seal against the inner surface of the delivery channel 104 .

[0071] FIG. 7 shows an outer sleeve 108A and corresponding retaining collar 106A having a smaller diameter than the larger sleeve 108B and retaining collar 106B shown in FIG. 7B.

[0072] For example, outer sleeve 108A and retaining collar 106A may have a 14 mm outer diameter suitable for a 14 mm delivery channel 104, while outer sleeve 108B and retaining collar 106B may have an 18 mm outer diameter suitable for an 18 mm delivery channel. Each expanding seal 135 may likewise have a corresponding diameter.

[0073] A proximal annulus 110 having a pivot handle 111 may be supported on the proximal end of the outer sleeve 108 and may urge the outer sleeve 108 along the inner conduit 109 toward the distal end to compress the expanded seal 135 against the retaining collar 106. The annulus 110 may include internal threads that engage external threads 132 on the proximal end of the inner conduit 109.

[0074] The packer 105 may have a main cylindrical handle 133 connected to the internal conduit 109 .

[0075] The main cylindrical handle 133 may have a bore 134 therethrough that fluidly connects the internal conduit 109. The internal bore 134 may have suitable internal threads for connecting a delivery hose thereto.

[0076] Thus, during use, the main cylindrical handle 133 may be held in one hand while the pivot handle 111 is rotated.

[0077] For example, a delivery hose may be connected to bore 134 in main handle 133 and the distal end of delivery nozzle 131 may be inserted into delivery channel 104 to inject sealant in step 121 as shown in FIG.

[0078] Once the required insertion depth is reached, while firmly holding the main handle 133, the pivot handle 111 may be rotated clockwise to urge the outer sleeve 108 towards the distal retention collar 106, causing the expanding seal 135 to expand against the inner surface of the delivery conduit 104, forming a tight seal and allowing the sealant to be injected under pressure into the crack 101.

[0079] If desired, a hex nut 136 or similar may be used to move the handle 133 using a wrench.

[0080] To remove the delivery nozzle 131, the reverse procedure may be followed, rotating the pivot handle 111 counterclockwise to loosen the expansion seal 135 and allow the delivery nozzle 131 to be removed.

[0081] Assuming that the expanding seal 135A and the retaining collar 106A are engaged with the 14 mm diameter outer sleeve 108A, reconfiguring the packer 105 for the 18 mm diameter delivery channel 104 may include manually loosening the retaining collar 106 and then sliding the expanding seal 135A and the outer sleeve 108A from the inner conduit 109. The outer sleeve 108A and the expanding seal 135A may have an inner diameter that clears the distal threads of the inner conduit 109 for engaging the retaining collar 106A.

[0082] An 18 mm diameter outer sleeve 108B may then be slid onto the inner conduit 109, followed by an 18 mm diameter expansion seal 135B, followed by an 18 mm diameter retaining collar 106B, which may then be threaded onto the threads at the distal end of the inner conduit 109.

[0083] In step 122, water may be injected via injection packer 105 to assess the extent of crack 101.

[0084] As shown in FIG. 5, in step 123, a sealant 113 is injected into the crack 101.

[0085] A sealant pump may supply sealant 113 from the sealant reservoir through hose connector 112. A compressor may supply air at the volume and pressure required to pressurize the sealant reservoir to pump sealant 113 through hose connector 112. The compressor may be adjustable to vary the amount and pressure of sealant 113 supplied.

[0086] The sealant 113 comprises latex and water, preferably in a ratio of about 3:2. The sealant 113 may also include a base to maintain the pH of the sealant 113 above 7.5 (preferably a pH of about 10-10.5) prior to application to allow for its long-term storage. The base may include a weak base such as ammonia.

[0087] Care must be taken not to inject the sealant 113 at too much pressure as it will thicken under shear. Care must also be taken to avoid aeration.

[0088] In one embodiment, 1 L of sealant 113 contains about 600 ml of latex, about 398 mL of water, and about 2 mL of ammonia. The water for sealant 113 may be tested before mixing to ensure that it has a neutral pH.

[0089] In step 124, a reactive agent 115 is applied which cures the sealant 113. The reactive agent 115 is applied to reduce the pH of the sealant 113 from a pH of about 10-10.5 to about 7-7.5, which has been shown through trial and experimentation to be the optimum pH for the sealing properties of the resulting sealant 113.

[0090] The formulation of the reactive agent 115 may be selected depending on the pH of the reactive agent 115 and the pH of the water seeping from the crack 101, resulting in an optimal sealant pH of about 7 to 7.5.

[0091] For example, for water having a pH of less than 7-7.5, a first formulation of reactive agent 115 may be selected, comprising 1 L of approximately 995 mL of water, approximately 3 mL of calcium chloride, and approximately 2 mL of sodium chloride.

[0092] The amount of sodium chloride may be varied according to the table below depending on the pH of the water. [Table 1]

[0093] For water having a pH greater than 7, a second formulation of reactive agent 115 may be selected, comprising 1 L of approximately 995 mL of water and approximately 5 mL of calcium chloride.

[0094] The amount of calcium chloride may be varied according to the table below depending on the pH of the water. [Table 2]

[0095] The first formulation of reactive agent 112 may be selected for application to freshwater or groundwater, typically having a pH in the range of 6 to 8.5. The second formulation of reactive agent 115 may be used for saltwater, typically having a pH in the range of about 7.6 to 8.4.

[0096] As shown in FIG. 5, sealant 113 may be injected until it forms a weep 114 on the outer surface of crack 101 .

[0097] As shown in FIG. 6, in step 125, a spray gun 107 may be used to spray a reactive agent 115 onto the exudate 114, which causes the exposed sealant 113 to harden and form a coating 116.

[0098] Once the coating 116 is formed, thereby sealing the entrance to the crack 101, additional sealant 113 may be injected through the injection packer 105, which is forced deeper into the crack 101 by being blocked by the barrier formed by the outer coating 116. At this time, the sealant 113 may be injected under higher pressure, which may range from 500 to 2500 psi, in step 127.

[0099] If desired, a reactive agent may be injected through delivery channel 104 to cure sealant 113 from the rear.

[0100] Sealant 113 may be similarly injected through the other delivery channel 104 to seal the crack 101 .

[0101] Once a sufficient amount of sealant 113 has been injected, in step 128 , the sealant 113 may be allowed to cure to form a firm but flexible seal, which effectively seals the crack 101 .

[0102] In the foregoing description, for purposes of explanation, specific nomenclature was used to provide a thorough understanding of the invention. However, it will be apparent to those skilled in the art that specific details are not required in order to practice the present invention. Thus, the foregoing descriptions of specific embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise forms disclosed, as many modifications and variations are obviously possible in light of the above teachings. The embodiments were chosen and described to best explain the principles of the invention and its practical application, thereby enabling those skilled in the art to best utilize the various embodiments and variations thereof with various modifications as may be suited to the particular use contemplated. It is intended that the following claims and their equivalents define the scope of the invention.

[0103] As used herein, "about" or similar terms should be interpreted as within 10% of the stated value, unless otherwise specified.

Claims

1. 1. A method of sealing a leaking crack in a structure, comprising: drilling a delivery channel in the structure adjacent to the leaking crack toward the leaking crack so as to merge with the leaking crack; inserting a delivery nozzle into the delivery channel and injecting a sealant comprising latex and water into the leaking crack under pressure through the delivery nozzle; injecting the sealant until the sealant forms a weep on the outer surface of the leak crack; spraying the seepage with a reactive agent to cure the sealant over the entire surface of the leaking crack and form a coating over the entire outer surface of the leaking crack that is continuous with and synonymous with the sealant in the leaking crack; injecting additional sealant through the delivery channel after the coating is formed; and allowing the sealant to cure to provide a flexible, durable seal for the leak crack; A method for providing the above.

2. 10. The method of claim 1, wherein injecting the additional sealant through the delivery channel after the coating is formed further comprises increasing the pressure of the sealant to a range of 500 to 2500 psi.

3. 10. The method of claim 1, further comprising the step of injecting additional reactive agent through the delivery channel after injecting additional sealant to allow the sealant to cure into a flexible, durable seal within the leak crack.

4. drilling additional delivery channels along the length of the leaking crack; and The method of claim 1 , further comprising injecting additional sealant through the additional delivery channel.

5. The method further comprises using an injection packer comprising the delivery nozzle having an internal conduit through which sealant is injected into the delivery channel and at least one replaceable external sleeve retainable around the internal conduit; The method of claim 1 , wherein the interchangeable outer sleeves have different outer diameters that correspond to the inner diameters of the respective delivery channels.

6. 6. The method of claim 5, wherein the injection packer further comprises at least one replaceable distal retention collar retainable around the inner conduit at the distal end of the delivery nozzle and cooperating with respective outer sleeves of the same diameter to compress an expanding seal therebetween, thereby expanding the expanding seal to seal the delivery channel.

7. 7. The method of claim 6, wherein the inner conduit threadably engages an annular body having a pivot handle that, when rotated in a first direction, urges an attached outer sleeve toward the distal end to compress the expanded seal against an attached distal retention collar.

8. The method further comprises using an injection packer comprising a proximal annulus, an inner conduit, and a distal collar attachable to a distal end of the inner conduit; the proximal annulus and the distal collar are each supported on either end of an outer sleeve; The method of claim 1 , wherein the method comprises tightening the proximal annulus to bear the weight of the outer sleeve on the distal collar, causing the distal collar to expand within the delivery channel.

9. 10. The method of claim 1 further comprising a weak base such as ammonia that maintains the pH of the sealant above 7.5 prior to application.

10. 10. The method of claim 9, wherein the water contained in the sealant is tested to ensure it has a neutral pH before mixing.

11. The method of claim 10, wherein the reactive agent is formulated to lower the pH of the sealant to about 7 to 7.

5.

12. The method comprises: Determining the pH of water leaking from the leak crack; and selecting a reactive agent formulation that results in an optimal sealant pH of about 7.0 to 7.5 depending on the pH of the reactive agent and the pH of the water leaking through the leaking crack; The method of claim 11 further comprising:

13. 13. The method according to claim 12, wherein when the water leaking from the leaking crack has a pH of less than 7 to 7.5, such as fresh water or groundwater, a first formulation of a reactive agent containing sodium chloride is selected, and the amount of sodium chloride is changed according to the pH of the water leaking from the leaking crack.

14. 13. The method according to claim 12, wherein when the water leaking from the leaking crack has a pH greater than 7, such as saltwater, a second formulation of reactive agent containing calcium chloride is selected, and the amount of calcium chloride is changed according to the pH of the water leaking from the leaking crack.

15. 10. The method of claim 1, wherein the delivery channel extends at an angle of about 45 degrees to a depth of 100-200 mm.

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