AU665479B2 - Method of sealing concrete structure - Google Patents
Method of sealing concrete structure Download PDFInfo
- Publication number
- AU665479B2 AU665479B2 AU53851/94A AU5385194A AU665479B2 AU 665479 B2 AU665479 B2 AU 665479B2 AU 53851/94 A AU53851/94 A AU 53851/94A AU 5385194 A AU5385194 A AU 5385194A AU 665479 B2 AU665479 B2 AU 665479B2
- Authority
- AU
- Australia
- Prior art keywords
- face
- seepage
- concrete structure
- aqueous
- region
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Ceased
Links
- 238000000034 method Methods 0.000 title claims description 30
- 238000007789 sealing Methods 0.000 title claims description 13
- 239000000243 solution Substances 0.000 claims description 50
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 37
- BHPQYMZQTOCNFJ-UHFFFAOYSA-N Calcium cation Chemical compound [Ca+2] BHPQYMZQTOCNFJ-UHFFFAOYSA-N 0.000 claims description 31
- 229910001424 calcium ion Inorganic materials 0.000 claims description 31
- BPQQTUXANYXVAA-UHFFFAOYSA-N Orthosilicate Chemical compound [O-][Si]([O-])([O-])[O-] BPQQTUXANYXVAA-UHFFFAOYSA-N 0.000 claims description 24
- 239000007864 aqueous solution Substances 0.000 claims description 7
- 239000000080 wetting agent Substances 0.000 claims description 5
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical compound [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 claims description 4
- 239000011575 calcium Substances 0.000 claims description 4
- 229910052791 calcium Inorganic materials 0.000 claims description 4
- 230000002706 hydrostatic effect Effects 0.000 claims description 4
- 239000004115 Sodium Silicate Substances 0.000 claims description 3
- VSGNNIFQASZAOI-UHFFFAOYSA-L calcium acetate Chemical compound [Ca+2].CC([O-])=O.CC([O-])=O VSGNNIFQASZAOI-UHFFFAOYSA-L 0.000 claims description 3
- 229960005147 calcium acetate Drugs 0.000 claims description 3
- 235000011092 calcium acetate Nutrition 0.000 claims description 3
- 239000001639 calcium acetate Substances 0.000 claims description 3
- 238000012544 monitoring process Methods 0.000 claims description 3
- NTHWMYGWWRZVTN-UHFFFAOYSA-N sodium silicate Chemical compound [Na+].[Na+].[O-][Si]([O-])=O NTHWMYGWWRZVTN-UHFFFAOYSA-N 0.000 claims description 3
- 229910052911 sodium silicate Inorganic materials 0.000 claims description 3
- 238000002347 injection Methods 0.000 description 7
- 239000007924 injection Substances 0.000 description 7
- 239000000378 calcium silicate Substances 0.000 description 4
- 229910052918 calcium silicate Inorganic materials 0.000 description 4
- OYACROKNLOSFPA-UHFFFAOYSA-N calcium;dioxido(oxo)silane Chemical compound [Ca+2].[O-][Si]([O-])=O OYACROKNLOSFPA-UHFFFAOYSA-N 0.000 description 4
- 230000000694 effects Effects 0.000 description 4
- 239000000356 contaminant Substances 0.000 description 3
- 239000000203 mixture Substances 0.000 description 3
- 238000005086 pumping Methods 0.000 description 3
- -1 sulphate ions Chemical class 0.000 description 3
- 230000015572 biosynthetic process Effects 0.000 description 2
- 230000009977 dual effect Effects 0.000 description 2
- 238000005755 formation reaction Methods 0.000 description 2
- 239000002244 precipitate Substances 0.000 description 2
- 238000001556 precipitation Methods 0.000 description 2
- 230000003014 reinforcing effect Effects 0.000 description 2
- OXIDJYIUYWHJRZ-UHFFFAOYSA-N 1-[[2-(2,4-dichlorophenyl)-4-propyl-1,3-dioxolan-2-yl]methyl]-1,2,4-triazole;methyl n-(1h-benzimidazol-2-yl)carbamate Chemical compound C1=CC=C2NC(NC(=O)OC)=NC2=C1.O1C(CCC)COC1(C=1C(=CC(Cl)=CC=1)Cl)CN1N=CN=C1 OXIDJYIUYWHJRZ-UHFFFAOYSA-N 0.000 description 1
- VEXZGXHMUGYJMC-UHFFFAOYSA-M Chloride anion Chemical compound [Cl-] VEXZGXHMUGYJMC-UHFFFAOYSA-M 0.000 description 1
- 230000015556 catabolic process Effects 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 239000000470 constituent Substances 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 239000003822 epoxy resin Substances 0.000 description 1
- LNEPOXFFQSENCJ-UHFFFAOYSA-N haloperidol Chemical compound C1CC(O)(C=2C=CC(Cl)=CC=2)CCN1CCCC(=O)C1=CC=C(F)C=C1 LNEPOXFFQSENCJ-UHFFFAOYSA-N 0.000 description 1
- 238000002386 leaching Methods 0.000 description 1
- 230000007774 longterm Effects 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 229920000647 polyepoxide Polymers 0.000 description 1
- 239000011148 porous material Substances 0.000 description 1
- 230000001737 promoting effect Effects 0.000 description 1
- 230000001681 protective effect Effects 0.000 description 1
- 229920006395 saturated elastomer Polymers 0.000 description 1
- 229910021653 sulphate ion Inorganic materials 0.000 description 1
- 238000009736 wetting Methods 0.000 description 1
Landscapes
- Building Environments (AREA)
Description
I~
665479
AUSTRALIA
Patents Act 1990 COMPLETE SPECIFICATION For a Standard Patent
ORIGINAL
400004 0o I a i ea o o 0 0 00 0 0 ^0 os oo o a a 0 a a 0 04 00 00 oae 0404 0 00 0 O B 0 4 00 0 TO BE COMPLETED BY APPLICANT Name of Applicant: Actual Inventor(s): Address for Service: NOTWHEAT PTY LTD BRIAN CUTLER WRAY ASSOCIATES, Primary Industry House, Terrace, Perth, Wester- Australia, 6000.
239 Adelaide Attorney code: WR 1 1 0 4 0 Invention Title: "METHOD OF SEALING CONCRETE STRUCTURE" 1: Details of Associated Provisional Application: No: PL6838 The following statement is a full description of this invention, including the best method of performing it known to us:- -1- I -2- THIS INVENTION relates to a method of sealing concrete structures.
In particular the invention has application to the sealing of concrete structures which are located in a water bearing medium and which are required to provide a protective environment from the water bearing medium. Such structures can comprise underwater tunnels, caissons, pylons, walls, slabs and building foundations which may be located underwater or in water bearing ground formations.
Throughout the specification the term "concrete structure" is to be taken to include the abovementioned structures.
The previous methods of sealing concrete structures have comprised the application of sealing composition to the "dry" side of the structure. Such compositions have generally comprised epoxy resins, caulking compositions j °and the like which are applied over the "dry" surface in the region of the ,seepage and in some cases over the whole of the "dry" surface. While such S, methods have in some cases been satisfactory in the short term in preventing any further seepage of water from the concrete structure in the region of the seepage it has been found that such a method has not provided a long term solution to the problem. The difficulty with such previous systems is that the concrete structure in the region of the seepage remains saturated. As a result the contaminants contained in the water, such as sulphate ions and chloride ions, in the water can effect the integrity of the concrete structure by promoting o or facilitating corrosion of the reinforcing within the concrete structure and the breakdown of the bonding between the particles of the concrete.
Accordingly the invention resides in a method of sealing a concrete structure of the form described above where one face is in contact with the water bearing medium, the -3method comprising monitoring the presence of calcium ions in water flowing to the other face of the structure at seepage locations in the structure, and where the calcium ions are of a predetermined concentration, introducing an aqueous silicate solution to the one face in the region of the seepage location, maintaining the delivery of the aqueous silicate until the passage of water through to the other face at the seepage locations is substantially eliminated.
According to a preferred feature where the concentration of calcium ions is less than the predetermined concentration, said method further comprising introducing an aqueous solution containing calcium ions at the one face in the region of the seepage location, prior to and/or in conjunction with the application of the aqueous silicate solution maintaining the delivery of the calcium ion solution, if required, and/or the aqueous silicate solution, to the one face until the passage of water through to the other face at the seepage locations is substantially eliminated.
.0 According to a further preferred feature of the invention, a set of pipes or e e 4 S: conduits or the like are located in the region of the seepage location for the 0 0° delivery of aqueous silicate solution to the one face of the concrete structure in the region of the seepage location.
0*0: According to a further preferred feature of the invention, a second set of pipes or conduits or the like are located in the region of the seepage location for the delivery of aqueous calcium solution to the one face of the concrete structure in the region of the seepage location.
According to a further preferred feature of the invention the set of pipes or conduits are located within the one face of the concrete structure.
4 According to yet another preferred feature of the invention, the set of pipes or conduits or the like are located adjacent the external surface of the one face of the concrete structure in the region of the seepage location to allow for direct delivery of solutions to the one face of the concrete structure.
According to another preferred feature of the invention at least one passage is formed through the concrete structure in the region of the seepage location, where the passage extends to the one face of the concrete structure, and the solutions are delivered through said passage.
According to another preferred feature of the invention a passage is formed in the water bearing medium to terminate adjacent the one face in the region of the seepage location and said solutions are delivered through the passage.
According to yet another preferred feature of the invention the aqueous solutions are applied to the one face of the concrete structure, in the region of the seepage location, under pressure at least equal to the hydrostatic pressure of the one face.
According to yet another preferred feature of the invention the aqueous silicate solution is applied in association with an appropriate wetting agent or wetting agents.
According to another preferred feature of the invention the pipes or conduits can be isolated into sections to allow selective delivery of the aqueous solutions to various locations along the concrete structure.
According to another preferred feature of the invention the aqueous calcium solution is calcium acetate.
I
-t 5 According to another preferred feature of the invention the aqueous silicate solution is sodium silicate.
The invention will be more fully understood in the light of the following description of several specific embodiments.
The embodiment relates to a r.ethod for preventing the seepage of water through a concrete structure where one face of the concrete structure is in contact with a water bearing medium.
It is an important feature of the embodiment that the concentration of calcium ions contained within the water seeping through the concrete structure is of a predetermined concentration. Therefore it is necessary to measure the concentration of calcium ions in the water seeping through to the other face of the concrete structure at the seepage location.
The method comprises forming a series of holes through the concrete structure in the region of the seepage location where the holes extend through to the one face of the concrete structure which is located in the water bearing medium. Suitable pipes or conduits are located in each of the holes and each of the conduits are connected to a pump.
Where it is found that the concentration of calcium ions in the water being carried through the concrete structure is sufficiently high, an aqueous solution of sodium silicate is introduced through the pipes or conduits into the region surrounding the seepage location at the one face.
As a result the silicate solution is dispersed into the water surrounding the seepage location at the one face and is carried through the seepage locations in the concrete structure through to the other face. Due to the presence of the calcium ions, calcium silicate will precipitate from 6 solution in the seepage flow paths and become deposited in the seepage flow paths in the concrete structure. Due to the presence of calcium ions, in the region of the one face, calcium silicate may also precipitate from solution and become deposited on the one face thus adding further to the sealing effect.
During the injection process the water seeping to the other face of the concrete structure is monitored to monitor the concentration of calcium ions in the water being carried through the structure. In the event that there is insufficient calcium ions in the water which is being carried through the concrete structure to guarantee the precipitation of calcium silicate, an aqueous solution containing calcium ions in the form of a solution of calcium acetate is injected through the pipes into the region surrounding the seepage locations together with the solution of silicate ions in order to increase the concentration of calcium ions.
The injection of the calcium ion solution and the silicate solution is effected through separate series of conduits surrounding the leakage or seepage points and the solutions are delivered to the conduits through a dual action pump.
The ratio of the calcium ion solution and silicate solution being delivered to the one face of the concrete structure is adjusted according to the concentration of calcium ions contained in the water being carried to the other face of the concrete structure through the seepage flow paths. The injection of the calcium ion solution and the silicate solution into the concrete structure is maintained until there is no further seepage of water at the location.
The silicate solution is associated with appropriate wetting agents to ensure that the silicate solution passes through and into all of the interstices surrounding the seepage locations for reaction with calcium ions which may o Q o 00 0 0000 00 00 -7 be present as a result of the injection of the calcium ion solution or as a result of leaching the calcium ions from the concrete structure.
The dual action pump which is utilised in the delivery of the calcium ion solution and the silicate solution comprises a pair of pumps which are driven from a common drive shaft where each pumping chamber is provided with a diaphragm which is caused to move to increase and decrease the volume of the pumping chamber through the application of hydraulic pressure. The required ratio of solutions passing from each pump is varied by varying the degree of diaphragm travel in each pumping chamber. The pump is capable of producing a wide variety of pressures in order to be able to counteract the hydrostatic pressure which may exist at the one face of the concrete structure to ensure the injection of each solution into the region surrounding the one face. By utilisation of the pump a very accurate control is maintained of the ratio of calcium ions to silicate ions being introduced into the region surrounding 20 the seepage location and the pressure of injection into that face can be controlled to match the hydrostatic pressure.
The method of controlling seepage and leakage through a concrete structure can be utilised in existing concrete structures by the formation of passageways through the concrete structure and installing of pipes through those passageways for connection to the pump. In addition the method can be utilised in new concrete structures by installing outside the concrete structure a network of conduits which have delivery outlets opening into the one face of the new concrete structure where the network may comprise a number of circuits which can be isolated from each other for the delivery of the appropriate solutions to specific locations at the one face of the concrete
I_
-8structure in the event of a leakage occurring in the concrete structure due to subsequent structural movement.
In some instances it is not possible or appropriate to gain access to the one face of the concrete structure by forming holes through the concrete structure from the other face. In such instances the injection of the calcium ion solution (if required) and the silicate solution can be effected by direct application to the one face. This can be effected by locating the pipe work delivering the solution in the water bearing medium around the exterior of the concrete structure such that the delivery point of the conduit is located adjacent the seepage location.
In the case of an underground tunnel or building foundation, holes are bored through the ground to the location adjacent the concrete structure through which pipes are passed for delivering of the solutions to the desired locations.
If the concrete structure is located underwater delivery pipes can be mounted to the exterior of the structure such that the outlets are located directly adjacent the structure in the region of the seepage locations whereby the solutions will be delivered to the surface of the structure in the region of the seepage and be drawn into the concrete structure as a result of the water flow therethrough. If a general application is to be applied over the whole of a concrete structure which may have suffered significant deterioration, a network of conduits can be located adjacent the exterior face of the structure for the application of the cc r the whole of the exterior face.
The effect of the method according to the embodiment is that the sealing action is effected by materials which are carried by the water as it enters the structure and therefore any pores, microcracks or other minute interstices have the sealing agent delivered into them by the water. On the precipitation of calcium silicate in
Q
k -9such spaces in the concrete no further water is permitted to pass through those locations which prevents any further wetting or saturation of the concrete structure and contaminant damage to the integrity of the concrete structure by the presence of water and any undesirable contaminants which may effect the reinforcing and/or the bonding between the constituents of the concrete.
It should be appreciated that the scope of the present invention need not be limited to the particular scope of the embodiment described above.
qta tilt C It ct 1 i cI L.it
Claims (14)
1. A method of sealing a concrete structure where one face of the structure is in contact with a water bearing medium comprising monitoring the presence of calcium ions in water flowing to the other face of the structure at seepage locations in the structure, and where the calcium ions are of a predetermined concentration, introducing an aqueous silicate solution to the one face in the region of the seepage location maintaining the delivery of the aqueous silicate until the passage of water through to the other face at the seepage locations is substantially eliminated.
2. A method of sealing a concrete structure as claimed at claim 1 where the concentration of calcium ions is less than the predetermined concentration, said method further comprising introducing an aqueous solution containing calcium ions at the one in the region of the seepage location, prior to and/or in conjunction with the application of the aqueous silicate solution, maintaining the delivery of the calcium ion solution, if required, and/or the aqueous silicate solution, to the one face until the passage of water through to the other face at the seepage locations is substantially eliminated.
3. A method as claimed in claim 1 or 2 where a set of pipes or conduits or the like are located in the region of the seepage location for the delivery of aqueous silicate solution to the one face of the concrete structure in the region of the seepage location.
4. A method as claimed in claim 3 as dependant on claim 2 wherein, a second set of pipes or conduits or the like are provided for the delivery of aqueous calcium solution, to the one face of the concrete structure in the region of the seepage location.
Ii A method as claimed in claim 3 where the set of pipes or conduits are located within the one face of the concrete structure.
6. A method as claimed in claim 3 only where the set of pipes or conduits are located adjacent the external surface of the one face of the concrete structure.
7. A method as claimed in any one of claims 1 to 3 comprising forming at least one passage through the concrete structure in the region of the seepage location where the passage extends to the one face of the concrete structure, and delivering the solutions through said passage.
8. A method as claimed in any one of claims 1 to 3 wherein a passage is formed in the water bearing medium to terminate adjacent the one face in the region of the seepage location and said solutions are delivered through the passage.
9. A method as claimed in claims 1 to 8 where the aqueous solutions are delivered to the one face under pressure at least equal to the hydrostatic S* pressure at said face.
I o oe A method as claimed in any one of claims 1 to 9 where the aqueous silicate solution is associated with an appropriate wetting agent or wetting agents.
11. A method as claimed in any one of claims 1 to 10 where the sets of pipes or conduits can be isolated into sections.
12. A method as claimed in anyone of claims 1 to 11 wherein the aqueous calcium solution is calcium acetate. 11 -P~-XUCII: 12
13. A method as claimed in any one of claims 1 to 12 wherein the aqueous silicate solution is sodium silicate.
14. A method substantially as herein described. DATED this EIGHTEENTH day of NOTWHEAT PTY LTD Applicant. JANUARY 1994 0I 0 ow t 09 I 9 0I 000 WRAY ASSOCIATES, Perth, Western Australia, Patent Attorneys for the Applicant. 0600 a 41 011440e J, I e e L~, S13 jABSTRACT A method of sealing a concrete structure where one face of the structure is in contact with a water bearing medium comprising monitoring the presence of calcium ions in water flowing to the other face of the structure at seepage o locations in the structure, and where the calcium ions are :.00 of a predetermined concentration, introducing an aqueous 00o silicate solution to the one face in the region of the 0 00 :0"0o seepage location maintaining the delivery of the aqueous oo silicate until the passage of water through to the other face at the seepage locations is eliminated. lo
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| AU53851/94A AU665479B2 (en) | 1993-01-18 | 1994-01-18 | Method of sealing concrete structure |
| AU60715/96A AU718099B2 (en) | 1994-01-18 | 1996-07-25 | Method of sealing non-cementitious structures |
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| AUPL683893 | 1993-01-18 | ||
| AUPL6838 | 1993-01-18 | ||
| AU53851/94A AU665479B2 (en) | 1993-01-18 | 1994-01-18 | Method of sealing concrete structure |
Related Child Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| AU60715/96A Addition AU718099B2 (en) | 1994-01-18 | 1996-07-25 | Method of sealing non-cementitious structures |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| AU5385194A AU5385194A (en) | 1994-07-21 |
| AU665479B2 true AU665479B2 (en) | 1996-01-04 |
Family
ID=25630221
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| AU53851/94A Ceased AU665479B2 (en) | 1993-01-18 | 1994-01-18 | Method of sealing concrete structure |
Country Status (1)
| Country | Link |
|---|---|
| AU (1) | AU665479B2 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| SE512797C2 (en) * | 1998-09-18 | 2000-05-15 | Penecrete Sverige Ab | Method, liquid composition and use of such liquid composition in sealing water-bearing capillaries in rock |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0121808A2 (en) * | 1983-04-12 | 1984-10-17 | Hüls Aktiengesellschaft | Isolation of noxious matters in soil layers |
| DD252030A1 (en) * | 1986-08-11 | 1987-12-02 | Freiberg Bergakademie | INJECTION METHOD FOR SEALING POROESEM AND A CRUCIBLE SALT CELERY |
| AU2056892A (en) * | 1991-07-31 | 1993-02-04 | Raw Patents S.A. | Flexible coating for insulating soils and equipment against water, air and gases |
-
1994
- 1994-01-18 AU AU53851/94A patent/AU665479B2/en not_active Ceased
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0121808A2 (en) * | 1983-04-12 | 1984-10-17 | Hüls Aktiengesellschaft | Isolation of noxious matters in soil layers |
| DD252030A1 (en) * | 1986-08-11 | 1987-12-02 | Freiberg Bergakademie | INJECTION METHOD FOR SEALING POROESEM AND A CRUCIBLE SALT CELERY |
| AU2056892A (en) * | 1991-07-31 | 1993-02-04 | Raw Patents S.A. | Flexible coating for insulating soils and equipment against water, air and gases |
Also Published As
| Publication number | Publication date |
|---|---|
| AU5385194A (en) | 1994-07-21 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MK14 | Patent ceased section 143(a) (annual fees not paid) or expired |