DD243707A5 - METHOD FOR INCREASING THE STRENGTH AND WATER RESISTANCE OF DEEP BUILDING OBJECTS AND THEIR ENVIRONMENT - Google Patents

Abstract

The invention relates to a method for increasing the strength and water resistance of civil engineering objects and the surrounding soil. The aim is to reduce the labor and material required, shorten working hours, avoid environmental pollution and reduce the requirement on the operating personnel. The object is to provide a method that is technologically simple to carry out and in which a gel is formed, which has a high strength and elasticity and is characterized by the action of water by a good Quellvermöegen. As a solution, a method is proposed in which a mixture of an aqueous water glass solution and at least 1 wt .-% of one or more compounds of the general formula in which R is hydrogen, -CH2OH group or a group of the general formula -CH2SO3M, wherein M is a monovalent Cation, R1 is hydrogen or -CH2OH group, n is an integer from 1 to 10, m is an integer from 0 to 10, p is an integer from 1 to 10 and r is an integer from 0 to 5 with the restrictions, in the compounds of the general formula (I) and (II) the number of -CH 2 OH groups is at least one greater than the number of -CH 2 SO 3 M groups, that the value of n is at least as large as the value of m, and the value of p is at least twice as large as the value of r and 1% by weight of mixtures containing one or more conventional aminoplastomers and / or oligomers.

Description

-CH ₂ -RN-C N

C-NR-CH ,, - O - 0-CH -R _0, NC.

C RN -CH "-SO" M

in which

R is hydrogen, -CH ₂ OH group or a group of the general formula -CH ₂ SO ₃ M, wherein M is a monovalent cation

stands,

R _{1 is} hydrogen or -CH ₂ OH group,

η is an integer from 1 to 10,

m a number of ObisiO,

p is an integer from i to lO and

r is an integer from 0 to 5

with the limitations that in the compounds of general formulas (I) and (II) the number of -CH ₂ OH groups is at least one greater than the number of -CH ₂ SO 3M groups that the value of η is at least as large as the value of m, and that the value of ρ is at least twice as large as the value of r and 1 wt .-% of one or more conventional aminoplastomers and / or oligomers-containing mixtures is used.

2. The method according to item 1, characterized in that are used as acidic substance inorganic or organic acids, preferably phosphoric acid, hexafluorosilicic acid, p-toluenesulfonic acid or acetic acid, suitably in the form of aqueous solution.

3. The method according to item!, Characterized in that as the acidic substance, an acidic hydrolyzing salt, preferably ammonium chloride or ammonium hexafluorosilicate, is used, preferably in the form of aqueous solution.

For this purpose 1 page formulas here 1 page drawings

Field of application of the invention

The invention relates to a method for increasing the strength and water impermeability of civil engineering objects (in particular channels and pipelines) and the surrounding soil.

The terms "building object" and "soil" are used here in the broadest sense of the word; apart from channels and pipelines, these include different reservoirs. Tunnels, artificial cavities, but also to understand the surrounding soil fractures and rock cracks.

Characteristic of the known technical solutions

It is known that the watertightness of most civil engineering structures, primarily of canals, pipelines and basins, is usually unsatisfactory. These deficiencies are largely due to manufacturing and joint defects (joints), cracks caused by wear and other deterioration of the property. It is also known that the repair of civil engineering structures and objects (primarily underground sewer networks and pipelines) is time, labor and material consuming and in many cases does not provide the desired result.

HU-PS 153975 describes a simple and rapid method for increasing the strength and watertightness of building and civil engineering objects, building elements, rocks and floors. According to this method, water glass or a water-glass-containing medium is placed in or on the object to be repaired or in its surroundings and exposed there to the action of hydrogen fluoride, silicon tetrafluoride and / or hydrogen silicofluoride. The water glass rapidly gels on contact with the gaseous fluoride and seals all cavities, crevices and cracks. If the method is used to increase the waterproofness of structures or objects located in the ground (eg channels or basins), there is another advantage in that also the water glass seeped out by cracks and crevices solidifies, thereby solidifying the embedding of the object and the strength of the surrounding soil improved. This method has not found its way into practice despite its numerous advantages. For a widespread application is a hindrance that the treatment gases hydrogen fluoride and silicon tetrafluoride are extremely toxic, their application is therefore unreasonable for reasons of environmental protection. Another disadvantage is that the resulting silica gel is not elastic, is unable to follow the movements of the treated object or the soil layer. Silica gel does not sufficiently swell due to the action of water, therefore it is unable to clog the new cracks forming by shifts adjacent to the gel plug.

It has already been proposed (Hungarian Patent Application No. MA-2924) to use as a gelling substance, instead of water glass, various organic polymers, primarily acrylic and acrylamide polymers, optionally containing inert, granular solid fillers. The gels formed in this way are correspondingly elastic and swell well by the action of water. Their disadvantage is that most of the usable polymers are relatively soft and therefore can not withstand a heavier load. Also, the polymers are expensive and difficult to obtain, and the technology sometimes requires special equipment and trained personnel.

Furthermore, in order to overcome these disadvantages, it has already been proposed (Hungarian Patent Application No. 3124/82) that the waterglass be used in admixture with different gel-forming, water-soluble organic polymers and space-crosslinking agents. The gels obtained in this way combine in themselves all the good properties of the purely organic and the purely inorganic gels. However, when using the large scale process, it has been found that the useful hydrogel-forming polymers - due to their high average molecular weight - greatly increase the viscosity of the water glass even in small amounts. For this reason, the treatment of the polymer-waterglass mixture, its application, dosing, removal of the excess amount raise numerous technological problems. It also happens that the required amount of polymer can not be mixed in the water glass solution, because such a highly viscous mixture is formed that it can not be applied to the surface to be treated with the available machine devices.

Object of the invention

The aim of the invention is to reduce the required labor and material costs, to shorten the working time, to avoid environmental pollution and to reduce the demands on the operating personnel.

Explanation of the essence of the invention

The object of the invention is to provide a method for increasing the strength and impermeability of civil engineering objects and the surrounding soil, which is technologically easy to carry out and in which a gel is formed, which has a high strength and elasticity and when exposed to water characterized by a good swelling capacity.

According to the invention the object is achieved in that a mixture of an aqueous water glass solution and at least 1 wt .-% of one or more compounds of the general formula

* 2

C-NR-CH, * - O - CH ₀ -RN-C-NR-CH

* "IMI ^^ 11I \ V ^ t 1 &

1-20

RN-CH ₂ -SO ₃ M

and or

HfO-CH ₀ -RN-C ^X C-NR-CH _9. -O-O-CH ₉ -R ₁ NC ⁷ C-NR ₁ -CH ₉ J

-I ^u NW

1-20

in which

^R 1 ^NR 1

R is hydrogen, -CH ₂ OH or a group of the general formula -CH ₂ SO ₃ M, where M is a monovalent cation,

R _{1 is} hydrogen or -CH ₂ OH group,

η an integer from 1 to10,

m a number of ObisiO,

ρ is an integer from 1 to 10 and

r is an integer from 0 to 5

with the restrictions mean that in the compounds of the general formulas (I) and (II) the number of -CH ₂ OH groups is at least one greater than the number of -CH ₂ SO ₃ M groups that the value of η is at least is as large as the value of m, and that the value of ρ is at least twice as large as the value of r and 1% by weight of mixtures containing one or more conventional aminoplastomers and / or oligomers.

From the compounds of the general formulas (I) and (II) and from their mixtures prepared with conventional aminoplast monomers or oligomers, the action of acidic substances produces an elastic, water-swellable gel which is excellently suitable for soil consolidation and for the exclusion of water ,

It has also been found that when the compounds of the general formulas (I) or (II) are mixed in an amount of at least 1% by weight to give water, a gel results from the resulting mixture by the action of acidic substances, the strength thereof , Elasticity and water absorbency is much better than that of the pure water glass formed gel.

The compounds of the general formulas (I) and (II) are known or can be prepared in a known manner; on their preparation as described in detail in the description of the embodiment. Some of these compounds are currently used as a concrete plasticizer (cement-lime plaster 21,415-419 / 1968 / and 22,297-305 / 1969 /). It is well known that the concrete premixes are strongly alkaline reacting systems and, therefore, the skilled artisan could not infer from the experience gained with the concrete plasticizers what properties any gels comprised of the compounds of general formulas (I) and (II ) by the action of acidic substances.

In the specification and in the claims, the term "waterglass" is understood to mean the alkali metal silicates and the ammonium silicate, most preferably the waterglass sodium silicate The dry matter content of the aqueous waterglass solution should preferably be about 35% by weight.

The term "acidic substances" is understood as meaning acids and acid-dissociating salts (for example ammonium chloride) Suitable acids are, for example, mineral acids, such as phosphoric acid or hexafluorosilicic acid, suitable acid-dissociating salts are, for example, ammonium chloride or ammonium hexafluorosilicate, expediently in the form of aqueous solutions according to the type and amount of the acidic substance, the gelation time (gel time) can be regulated at will within a wide range (generally between 10 minutes and 10 hours at room temperature).

The material streams can be brought into contact in any order. For example, the oligomer or monomer solution (which may also contain water glass) may first be placed on or in the object to be treated or in its surroundings, and then the solution of the acidic substance may be applied. The acidic substance may, if possible (for example when hexafluorosilicic acid is used as the acidic substance) also be contacted as gas with the other components of the yellow-forming system. Of course, conversely, the solution of the acidic substance can first be brought to the site of treatment and then the material stream containing the oligomers or monomers and optionally water glass can be introduced. However, this solution is less advantageous than the former. If necessary, the treatment may be repeated once or several times.

The acidic substance is suitably used in excess, based on the amount required for gelling the optionally also water glass-containing monomer or oligomer. If environmental considerations so require, the excess of the acidic substance in place can be readily neutralized by passing an alkaline reacting substance to the site of treatment.

The alkaline-reacting substance used is particularly suitably water glass solution (which may optionally also contain gel-forming, water-soluble organic polymers, oligomers or monomers). Furthermore, lime milk, dilute soda solution, etc. may also be used. It is expedient to combine this after-treatment with the test of the treated object for waterproofness.

The inventive method is advantageously combined with the aforementioned patents or patent applications solutions. According to a very advantageous embodiment, silicate gel is first formed in the manner described in the HU-PS 153975 at the place of treatment of water glass solution and fluoride gas and then applied in a second step, the inventive method.

If columns or cavities of large volumes are to be plugged in their entirety in the manner according to the invention, then the gap or cavity can be filled with granular solid substances (for example perlite, quartz sand, ash) which do not affect the gelation reaction, and the granular substances can be filled from the water-containing Material flow are admixed.

For the purpose of further enhancing the elasticity and deformability of the gel, the gel-forming system can also be composted with latex. For this purpose, natural or synthetic rubber latex and / or other water- and chemical-resistant polymer latex (for example homo- and copolymer latex based on acrylate or urethane) are placed on or in the object to be treated, where it spontaneously coagulates or coagulates with it an acidic substance and only then performs the inventive method. However, the latex may also be admixed with the oligomer or polymer solution, based on 1 part by weight of dry substance of this solution, a quantity of latex containing 0.005 to 1 part by weight, preferably 0.05 to 0.2 parts by weight of dry substance equivalent. This mixture is then contacted with the acidic substance. Finally, the latex can also be applied subsequent to the treatment according to the invention; in this .'.-,.··. , ,

In this case, it not only forms an additional waterproof layer but also serves to neutralize the unreacted acidic substance.

embodiment

The invention will be explained below some examples. In the accompanying drawing show:

1 shows a schematic representation of a lying between two Befahrungsschächten, to be repaired channel section, the

is filled with an oligomer solution according to Example 1; Fig. 2: the channel portion of FIG. 1, in which an acidic solution has been introduced.

example 1

Under laboratory conditions, trimethylol melamine is first formed at a temperature of 80 to 100 ° C from 1 mole of melamine and 3 moles of formaldehyde. This is added with vigorous stirring in small portions with 1 mol of sodium bisulfite, which reacts with the methylol group. Then, the solution nor V2 moles of urea and 1.5 moles of formaldehyde are added. The condensation reaction is continued until the viscosity of the solution is about 10OcP. This solution can be stored at room temperature for extended periods of time (several weeks) with no changes occurring.

If the pH of the solution is lowered to below 3 by the addition of phosphoric acid, the condensation process proceeds faster, and within 1 to 2 hours, a transparent, non-synergistic (syneresis: aging of the gel under water loss and volume shrinkage), elastic hydrogel, which is neither soluble in water nor in organic solvents and is excellent for increasing the soil strength and waterproofness. When operating in the manner described, with the difference that the reaction with sodium hydrogen sulfite is omitted, a milky cloudy solution is formed, which gels rapidly upon addition of phosphoric acid. The gel formed synergizes greatly and is therefore not suitable for water.

Example 2 "

In Fig. 1, a lying between two Befahrungsschächten 2 and 3, to be repaired channel section is shown. The previously cleaned channel section is closed with the tube closures 1 and then filled from the container 4 through the shaft 2 with the prepared according to the first section of Example 1 oligomer solution. The pressure required for the solution to penetrate the leaks 5 (eg, cracks, crevices, cavities, poorly fitting pipe joints, or porous pipe walls) is created by adjusting the height "m" of the liquid column in the well. The height "m" depends on the extent of the damage, suitably 1 to 2 m; if necessary, solution must be topped up. If in the well, the liquid level does not decrease further or sinks only very slowly (this is generally the case after 20 to 60 minutes, depending on the damage), the solution is removed from the channel section through the shaft 2 as quickly as possible (within from 5 to 10 minutes) is pumped back into the container 4.

Thereafter, in the manner shown in Fig. 2 through the shaft 2 through from a container 6 acidic solution is filled in the channel. The acid solution is a mixture of 10% hexafluorosilicic acid and 30% phosphoric acid in the ratio 1: 1. The acidic solution is filled into the channel as quickly as possible (within 5 to 10 minutes). This is to ensure that as little as possible of the solution pressed into the damaged areas flows back into the channel.

The filling level "m" of the acidic solution is expediently set higher by 0.5 to 1.0 m than the filling level "m" of the oligomer solution. The filling level is maintained by refilling if necessary.

If the liquid level in the well no longer drops (generally after 20 to 60 minutes), the solution is pumped back through the well 2 into the container 6. This completes the repair of the channel section. If the level of the acidic solution does not fall within 15 minutes, or drops only to an extent that is permissible under water-tightness regulations, the water-tightness of the channel is satisfactory. Simultaneously with the repair, it is thus also possible to test for leaks, thus making the usual leak test carried out with water or air after repair unnecessary. After removing the pipe caps, the duct section can be put into operation.

The solution squeezed or leaked out during the repair through the leaks, poor pipe joints, crevices and percolations of the channel gels and solidifies to form a watertight layer 5 in the surrounding soil. The repair not only completely sealed off all the crevasses of the channel, but also also the surrounding soil solidified and waterproofed. This also significantly improves the embedment conditions of the pipeline. Proper embedding is very important for the service life and dimensional stability of sewer networks.

For transporting the oligomer solution, the filling of the channel and pumping back the used for emptying drainage pits, provided with suction tube and pump motor vehicles are used with 3.5 to 10 m ³ tank volume expediently.

Corrosion resistant equipment (plastic containers, corrosion resistant pumps, etc.) is used to transport the acidic solution, fill the channel and pump back.

The first step of the channel repair, the filling of the oligomer solution in the closed channel section, at the same time serves to diagnose the damaged areas. The search for damaged areas has hitherto been carried out by means of a pressure test with water. In doing so, a considerable amount of water repeatedly entered the soil through the damaged areas, where it was able to submerge the canal, cause its sinking and thus lead to further damage. The inventively filled in the channel oligomer solution does not lead to Bodenauswaschungen due to their higher viscosity and their other nature.

This can be proved by calculation if the exfiltration measured after filling the channel with oligomer solution is converted. The conversion is not to be discussed here in detail; The viscosity of the solution, the pressure head "m", the specific gravity of the oligomer solution, etc. are included. It can be calculated that in the usual pressure test with water about 10 to 16 times as much water gets into the soil as oligomer solution under the same conditions.

Another advantage of the method is that at the same time three or more sections can be treated, together with the associated house branches, locks, gutter feeds, etc., because with the method according to the invention these are repaired simultaneously with the sewer repair. Depending on the equipment used, the amount of solution available and the internal dimensions of the channel to be repaired, sections of 30 to 100 meters in length can be processed at once. With appropriate organization and practical exercise as well as application of industrial methods, 2 to 3 such sections can be repaired successively in an 8-hour shift. For example, the solution may be pumped from the first repaired section to the previously completed second section and from there to the third section.

The method according to the invention offers the following further advantages in the case of sewer repairs:

The entire technological process of repair can be mechanized with relatively little cost and equipment. The amount of live work is extremely low, but the speed at which the repair proceeds is very large. The traffic is hardly hampered by the work, since it is not necessary to rip open the road surface. The procedure is not explosive and inflammable. By the method, the hydraulic properties of the channel do not deteriorate. The repaired channel requires no special maintenance costs. The method is also suitable for repairing channels deeper than the groundwater level. In these cases, the pressure level "m" is calculated by the groundwater level.

Since the process uses solutions, i. H. Liquids is carried out, a prior troubleshooting (which is generally cumbersome, time consuming, laborious and expensive) is not required. The solutions automatically find the damaged areas and seal them off.

The method is also suitable for repairing single defects (e.g., faulty pipe joints). In this case, not the entire channel section is filled, but with the help of suitable devices known per se only set the desired location under solution. In such cases, the channel generally does not need to be disabled for the duration of the repair because the design used has a flow tube through which the waste water can continue to flow.

Also at. Repairs with filling of the channel, it is possible to keep this during the period of repair in operation.

For example, the waste water can be pumped out of the shaft in front of the shut-off section. It is also possible, in the replenished section between the two pipe closures to lay an approximately half of the cross section of the channel engaging, elastic pipe through which the wastewater can flow. In most cases, however, neither of these two solutions is required because the repair takes only so short a time that the accumulation of water connected with the closing of the channel section causes no difficulties.

If a channel section to be repaired, in which there are several shafts, and are not filled to reduce the required amount of solution one of the middle shafts, the shaft concerned is provided at the inlet and outlet side with pipe closures, between which an operating pipe is laid.

The technology based on the use of two solutions has the further advantage that any gas which may be present but not known can escape into the environment.

Example 3

Eswirdwieinderim Example worked manner described 2, with the only difference that instead of pure oligomer A in the weight ratio 9: 1 Prepared mixture of sodium water glass solution of the concentration is 35-38 ⁰ Be and 20 wt .-% hydrochloric Melment L-20 solution. The results obtained are similar to Example 2.

If no Melment-L-20 solution (oligomer solution) is added to the water glass, the water-tightness of the repaired channel section is significantly lower. In the well filled with water, the water level decreases by about 10 mm / min, while when using water glass solution and oligomer solution, the sink rate of the water level is about 0.1 mm / min or even less.

Claims (1)

Invention claim: A process for increasing the strength and waterproofing of civil engineering structures and the surrounding soil, characterized in that a mixture of an aqueous solution of waterglass and at least 1% by weight of one or more compounds of the general formula _H f [o- CH ₂ RN-C : -nr-chJ-o-fCH-RN-c-NR-CH, ^{1 2} JL II OH 1-20 RN-CH ₂ -SO ₃ M and or