CA1277800C - Method of sealing water leakage in concrete structures - Google Patents
Method of sealing water leakage in concrete structuresInfo
- Publication number
- CA1277800C CA1277800C CA000523279A CA523279A CA1277800C CA 1277800 C CA1277800 C CA 1277800C CA 000523279 A CA000523279 A CA 000523279A CA 523279 A CA523279 A CA 523279A CA 1277800 C CA1277800 C CA 1277800C
- Authority
- CA
- Canada
- Prior art keywords
- water
- grouting
- organic polyisocyanate
- cracks
- pyrrolidone
- 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.)
- Expired - Fee Related
Links
Abstract
ABSTRACT OF THE DISCLOSURE
A mixture consisting of (1) an organic polyisocyanate compound and/or a prepolymer having terminal isocyanate residues, which is derived from the reaction of an organic polyisocyanate with a polyhydroxyl compound, and (2) 2-pyrrolidone is injected as grouting into water-leaking cracks or openings in concrete structures, such as water tanks, subway constructions and tun-nels. The injected mixture diffuses into the cracks or openings and is cured in a short time by reacting with water at the leak-ing sites. The resultant polyurethane foam securely seals the water leaking sites.
A mixture consisting of (1) an organic polyisocyanate compound and/or a prepolymer having terminal isocyanate residues, which is derived from the reaction of an organic polyisocyanate with a polyhydroxyl compound, and (2) 2-pyrrolidone is injected as grouting into water-leaking cracks or openings in concrete structures, such as water tanks, subway constructions and tun-nels. The injected mixture diffuses into the cracks or openings and is cured in a short time by reacting with water at the leak-ing sites. The resultant polyurethane foam securely seals the water leaking sites.
Description
77hUO
The present invention relates to the method of sealing cracks or openings to stop water leaks in concrete structures such as water tanks, subway constructions and tunnels by filling the leaking sites with a unique grouting material.
In concrete structures, cracks or openings appear due to various factors such as inappropriate constructions, changes in atmospheric temperature or humidity, differential settlement due to load change, and alkali-aggregate reaction. various types of grouting materials are conventionally used for sealing. The major categories of the materials are: (a) water-glass-contain-ing chemicals, (b) acrylamide-containing resins, (c) cement milk and cement motar, and (d) hydration-type (water-reactive) polyurethane foams.
Thus grouting materials have the following disadvan-tages: ta) grouting by water-glass-containing chemicals is gen-erally poor in durability and not suitable for a semipermanent sealing purpose. (b) Acrylamide-containing resins have poor flexibility and are not sufficiently cured in the presence of water. (c) Materials containing cement or mortar require rela-tively a long time for curing. Consequently, the grouting materials tend to be washed away by the leaking water before cur-ing is substantially carried out. (d) In the use of conventional polyurethane foams, most of air cells formed in the foams cured by the hydration reaction tend to be open and retain excess water. Consequently, the resultant polyurethane seals are frail and moreover, water leaks out through the water-retaining cells when the water pressure is high. Further, under a drying atmo-sphere, cured polyurethane foams shrink due to the loss ofretained water in the open cells of the foams and are stripped away, losing adhesion, from the leaking sites, resulting in water leakage.
The present invention provides a method of sealing of water-leaking cracks and openings in concrete structures.
~'~ 77 ~0~
The present invention provides grouting materials with a method of s~curely stopping water leakage in concrete structures with said materials.
According to the present invention there is provided a method of sealing water leakage in concrete structures which com-prises injecting a grouting mixture consisting of (1) an organic polyisocyanate compound and/or a prepolymer having terminal iso-cyanate residues, which is derived from the reaction of an organic polyisocyanate with a polyhydroxyl compound and (2) 2-pyrrolidone for grouting into water-leaking cracks or openings of concrete structures. More specifically, the use of 2-pyrrolidone has made it possible to provide an excellent material having such features required for sealings as short curing time, stoutness and adhesiveness.
Isocyanates to be used as primary ingredients in the present invention are, for example, organic polyisocyanates such as polymethylene-polyphenyl- (Crude MDI), diphenylmethane-diiso-cyanate (MDI) and toluylene-diisocyanate (TDI), and/or prepoly-mers having terminal isocyanate residues, which are derived from the reactions of above mentioned organic polyisocyanates with polyhydroxyl compounds having hydroxy residues.
The catalyst to be used in the present invention is 2-pyrrolidone. This agent acts not only as a catalyst to acceler-ate curing by hydration reaction but also as an excellent hydrophilic solvent.
Surface-active agents to be used, if necessary, in the present invention as foaming controlling agents are, for example, silicone surfactants.
The mixing ratios for the primary ingredients to the catalyst are 100 : ~5 to 50) by weight, preferably 100 : (20 to 40).
A grouting mixture consisting of the primary ingredi-ents, or isocyanates, the catalyst and, if necessary, other ingredients such as surfactants and pigments is put into an injection pump. The grouting mixture may be prepared at a work-ing site by mixing the individual ingredients. The grouting mix-ture may also be prepared as a form of premix which enables easy handling and transportation, since the mixture is not to be cured unless water is present. The premix can be stored in a container tightly sealed with nitrogen gas or dry air to avoid water. The grouting mixture is then injected through an injection pipe into a leaking site. Modifications in sealing methods at the leaking sites are possible as will be described in Examples.
Polyurethane foams with relatively high expansion ratios (volume of cured polyurethane foam / volume of starting material) is obtainable by the use of the grouting material according to the present invention, the expansion ratios ranging from 2 to 120.
Adoption of adequate expansion ratios, approximately from 10 to 100, result in producing polyurethane foams having sufficient adhesiveness to the concrete structures to assure effective sealing.
The method of sealing water leakage in concrete struc-tures according to the present invention will be given in the following Examples in conjunction with the accompanying drawings, in which:~
Figure 1 is an illustration for the method of sealing openings in a structure described in Example l;
Figure 2 is an illustration for a connection of an injection hose to a structure; and Figures 3, 4 and 5 are illustrations for seals described in Examples 2, 3, and 4.
Example 1:
~ .7 7 ~0 Polymethylene-polyphenyl-polyisocyanate (Crude MDI), 100 parts by weight, 2-pyrrolidone, 30 parts by weight, and sili-cone surfactant, 1 part by weight, were mixed for 20 seconds in a container to prepare a grouting mixture 4 and the mixture was put into a grout pump 1. The grouting 4 was injected to a leaking site of a structure 3 through a supply hose 2 which was connected to the grout pump 1 at one end and inserted into the leaking site at the other end (Fig. 1).
Alternately, as shown in the lower half of the Fig. 1, boring was made at a leaking site 5 and the grout was in~ected into the boring through an in;ectio~ pipe 8 fixed at the opening of the boring. The grout 4 thus injected ran through the boring and gradually reached the other end of the boring. Curing of the grout was completed in about 2 minutes to stop water leakage.
The specific gravity of the resultant polyurethane foam was 0.03 (expansion ratio of 30) and has cells mostly closed. This boring method is specifically useful when the cracks at leaking sites are minor and thin.
Alternately, a v-cut was made at the cracking site 5 and the injection pipe 8 was placed in the cut, the pipe end at the V-cut was fixed by using mortar 7 or the like (Fig. 2).
Example 2: (Fig. 3) A piece of a flexible and porous material 9 soaked with the grouting mixture in the present invention was pushed into an opening which had been expanded by making V-cut as described in the Example 1. The grouting mixture soaked ln the porous material was cured in short time, thus the quick and effective sealing was expected solely by pressing the grout-soaked porous material against the V-cut opening. The flexible and porous materials to be used in the present invention are sponges, clothes or the like.
~ - 4 -~ ~ 77 Example 3:
A sealing covering a relatively extended area of a con-crete structure is needed when thin and long cracks occur or when a concrete structure is locally porous mostly due to poor mixing which results in localization of excessive aggregates associated with an insufficient amount of mortar.
Fig. 4 illustrates an example of such a case, where a cover 10 was placed over the area of cracks and was fixed tem-porarily on the surface of the structure. The groutlng mixture in the present inventlon was ~n~ected into the interior of the cover through an injection pipe connected to the cover and was cured in short time by reacting with water. The resultant 1~ polyurethane foam was effectively stopped the water leakage of the covered area.
Example 4:
The grouting mixture in the present invention is also useful in areas of porous geologic structures such as peat bed.
The grouting is to be carried out in the same manner as in con-ventional grouting. Fig. 5 illustrates in;ection of the grouting mixture by using an injection pipe 11.
Accordingly, the grouting method in the present inven-tion has the following effects: (1) the grouting mixture accord-ing to the present invention is injected into openings or cracks at water leaking sites and is cured in a short time to form polyurethane foam having numerous closed cells which retain mini-mum amount of water. Consequently, the polyurethane sealings thus formed are stout and securely stop the water leakage.
Further, loss of adhesion due to shrin~age by drying can be pre-vented. ~2) The expansion ratios of polyurethane foams cured according to the present invention can be within the desirable ranges which result in excellent adhesiveness to concrete struc-~.~ 77 tures to assure effective sealing.
The present invention relates to the method of sealing cracks or openings to stop water leaks in concrete structures such as water tanks, subway constructions and tunnels by filling the leaking sites with a unique grouting material.
In concrete structures, cracks or openings appear due to various factors such as inappropriate constructions, changes in atmospheric temperature or humidity, differential settlement due to load change, and alkali-aggregate reaction. various types of grouting materials are conventionally used for sealing. The major categories of the materials are: (a) water-glass-contain-ing chemicals, (b) acrylamide-containing resins, (c) cement milk and cement motar, and (d) hydration-type (water-reactive) polyurethane foams.
Thus grouting materials have the following disadvan-tages: ta) grouting by water-glass-containing chemicals is gen-erally poor in durability and not suitable for a semipermanent sealing purpose. (b) Acrylamide-containing resins have poor flexibility and are not sufficiently cured in the presence of water. (c) Materials containing cement or mortar require rela-tively a long time for curing. Consequently, the grouting materials tend to be washed away by the leaking water before cur-ing is substantially carried out. (d) In the use of conventional polyurethane foams, most of air cells formed in the foams cured by the hydration reaction tend to be open and retain excess water. Consequently, the resultant polyurethane seals are frail and moreover, water leaks out through the water-retaining cells when the water pressure is high. Further, under a drying atmo-sphere, cured polyurethane foams shrink due to the loss ofretained water in the open cells of the foams and are stripped away, losing adhesion, from the leaking sites, resulting in water leakage.
The present invention provides a method of sealing of water-leaking cracks and openings in concrete structures.
~'~ 77 ~0~
The present invention provides grouting materials with a method of s~curely stopping water leakage in concrete structures with said materials.
According to the present invention there is provided a method of sealing water leakage in concrete structures which com-prises injecting a grouting mixture consisting of (1) an organic polyisocyanate compound and/or a prepolymer having terminal iso-cyanate residues, which is derived from the reaction of an organic polyisocyanate with a polyhydroxyl compound and (2) 2-pyrrolidone for grouting into water-leaking cracks or openings of concrete structures. More specifically, the use of 2-pyrrolidone has made it possible to provide an excellent material having such features required for sealings as short curing time, stoutness and adhesiveness.
Isocyanates to be used as primary ingredients in the present invention are, for example, organic polyisocyanates such as polymethylene-polyphenyl- (Crude MDI), diphenylmethane-diiso-cyanate (MDI) and toluylene-diisocyanate (TDI), and/or prepoly-mers having terminal isocyanate residues, which are derived from the reactions of above mentioned organic polyisocyanates with polyhydroxyl compounds having hydroxy residues.
The catalyst to be used in the present invention is 2-pyrrolidone. This agent acts not only as a catalyst to acceler-ate curing by hydration reaction but also as an excellent hydrophilic solvent.
Surface-active agents to be used, if necessary, in the present invention as foaming controlling agents are, for example, silicone surfactants.
The mixing ratios for the primary ingredients to the catalyst are 100 : ~5 to 50) by weight, preferably 100 : (20 to 40).
A grouting mixture consisting of the primary ingredi-ents, or isocyanates, the catalyst and, if necessary, other ingredients such as surfactants and pigments is put into an injection pump. The grouting mixture may be prepared at a work-ing site by mixing the individual ingredients. The grouting mix-ture may also be prepared as a form of premix which enables easy handling and transportation, since the mixture is not to be cured unless water is present. The premix can be stored in a container tightly sealed with nitrogen gas or dry air to avoid water. The grouting mixture is then injected through an injection pipe into a leaking site. Modifications in sealing methods at the leaking sites are possible as will be described in Examples.
Polyurethane foams with relatively high expansion ratios (volume of cured polyurethane foam / volume of starting material) is obtainable by the use of the grouting material according to the present invention, the expansion ratios ranging from 2 to 120.
Adoption of adequate expansion ratios, approximately from 10 to 100, result in producing polyurethane foams having sufficient adhesiveness to the concrete structures to assure effective sealing.
The method of sealing water leakage in concrete struc-tures according to the present invention will be given in the following Examples in conjunction with the accompanying drawings, in which:~
Figure 1 is an illustration for the method of sealing openings in a structure described in Example l;
Figure 2 is an illustration for a connection of an injection hose to a structure; and Figures 3, 4 and 5 are illustrations for seals described in Examples 2, 3, and 4.
Example 1:
~ .7 7 ~0 Polymethylene-polyphenyl-polyisocyanate (Crude MDI), 100 parts by weight, 2-pyrrolidone, 30 parts by weight, and sili-cone surfactant, 1 part by weight, were mixed for 20 seconds in a container to prepare a grouting mixture 4 and the mixture was put into a grout pump 1. The grouting 4 was injected to a leaking site of a structure 3 through a supply hose 2 which was connected to the grout pump 1 at one end and inserted into the leaking site at the other end (Fig. 1).
Alternately, as shown in the lower half of the Fig. 1, boring was made at a leaking site 5 and the grout was in~ected into the boring through an in;ectio~ pipe 8 fixed at the opening of the boring. The grout 4 thus injected ran through the boring and gradually reached the other end of the boring. Curing of the grout was completed in about 2 minutes to stop water leakage.
The specific gravity of the resultant polyurethane foam was 0.03 (expansion ratio of 30) and has cells mostly closed. This boring method is specifically useful when the cracks at leaking sites are minor and thin.
Alternately, a v-cut was made at the cracking site 5 and the injection pipe 8 was placed in the cut, the pipe end at the V-cut was fixed by using mortar 7 or the like (Fig. 2).
Example 2: (Fig. 3) A piece of a flexible and porous material 9 soaked with the grouting mixture in the present invention was pushed into an opening which had been expanded by making V-cut as described in the Example 1. The grouting mixture soaked ln the porous material was cured in short time, thus the quick and effective sealing was expected solely by pressing the grout-soaked porous material against the V-cut opening. The flexible and porous materials to be used in the present invention are sponges, clothes or the like.
~ - 4 -~ ~ 77 Example 3:
A sealing covering a relatively extended area of a con-crete structure is needed when thin and long cracks occur or when a concrete structure is locally porous mostly due to poor mixing which results in localization of excessive aggregates associated with an insufficient amount of mortar.
Fig. 4 illustrates an example of such a case, where a cover 10 was placed over the area of cracks and was fixed tem-porarily on the surface of the structure. The groutlng mixture in the present inventlon was ~n~ected into the interior of the cover through an injection pipe connected to the cover and was cured in short time by reacting with water. The resultant 1~ polyurethane foam was effectively stopped the water leakage of the covered area.
Example 4:
The grouting mixture in the present invention is also useful in areas of porous geologic structures such as peat bed.
The grouting is to be carried out in the same manner as in con-ventional grouting. Fig. 5 illustrates in;ection of the grouting mixture by using an injection pipe 11.
Accordingly, the grouting method in the present inven-tion has the following effects: (1) the grouting mixture accord-ing to the present invention is injected into openings or cracks at water leaking sites and is cured in a short time to form polyurethane foam having numerous closed cells which retain mini-mum amount of water. Consequently, the polyurethane sealings thus formed are stout and securely stop the water leakage.
Further, loss of adhesion due to shrin~age by drying can be pre-vented. ~2) The expansion ratios of polyurethane foams cured according to the present invention can be within the desirable ranges which result in excellent adhesiveness to concrete struc-~.~ 77 tures to assure effective sealing.
Claims (8)
1. A method of sealing water leakage in concrete structures which comprises injecting a grouting mixture consist-ing of (1) an organic polyisocyanate compound and/or a prepolymer having terminal isocyanate residues, which is derived from a reaction of an organic polyisocyanate with a polyhydroxyl com-pound and (2) 2-pyrrolidone into openings or cracks at a leaking site of a concrete structure and curing said grouting mixture by hydration reaction to form polyurethane foam to stop the water leakage.
2. A method as claimed in Claim 1, wherein mixing ratios of an organic polyisocyanate compound and/or a prepolymer to 2-pyrrolidone, are 100 : (5 to 50) by weight.
3. A method as claimed in Claim 1, wherein mixing ratios of an organic polyisocyanate compound and/or a prepolymer to 2-pyrrolidone, are 100 : (20 to 40) by weight.
4. A method as claimed in Claim 1, 2 or 3, wherein said grouting mixture is prepared as a form of a premix.
5. A method as claimed in Claim 1, 2 or 3, wherein expansion ratios for polyurethane foam cured are controlled within ranges from 2 to 120.
6. A method as claimed in Claim 1, 2 or 3, wherein expansion ratios for polyurethane foam cured are controlled within ranges from 10 to 100.
7. A method as claimed in Claim 1, 2 or 3, wherein areas including said openings and cracks are covered with a cover which is temporarily fixed on said concrete structure and then said grouting mixture is injected into the interior of said cover.
8. A method as claimed in Claim 1, 2 or 3, in which the ingredients (1) is polymethylene-polyphenyl-diphenylmethane-diisocyanate and toluylene-diisocyanate (TDI), and/or prepolymers having terminal isocyanate residues, which are derived from the reactions of above mentioned organic polyisocyanates with polyhy-droxyl compounds having hydroxy residues.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000523279A CA1277800C (en) | 1986-11-18 | 1986-11-18 | Method of sealing water leakage in concrete structures |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000523279A CA1277800C (en) | 1986-11-18 | 1986-11-18 | Method of sealing water leakage in concrete structures |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1277800C true CA1277800C (en) | 1990-12-11 |
Family
ID=4134382
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000523279A Expired - Fee Related CA1277800C (en) | 1986-11-18 | 1986-11-18 | Method of sealing water leakage in concrete structures |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1277800C (en) |
-
1986
- 1986-11-18 CA CA000523279A patent/CA1277800C/en not_active Expired - Fee Related
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKLA | Lapsed |