JPS63600B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a lock bolt fixing cartridge for fixing a lock bolt or the like in a hole drilled in a rock or the like to reinforce the rock or the like, and is particularly applicable to mines, power plants, etc.
This invention relates to a cartridge for fixing expandable lock bolts that is effective for strengthening soft rock in various tunnels such as roads and railways.

Conventionally, in tunnel construction, etc., a hole is drilled into soft rock, a lock bolt fixing cartridge is loaded into the hole, the lock bolt is then installed while rotating, and the fixing agent in the lock bolt fixing cartridge is stirred and hardened. A method is known in which a rock bolt is fixed in a hole in a rock.

However, in soft ground, the internal hole diameter becomes too large or there are cracks, making it impossible to fully fill the hole with adhesive. In order to raise
A fixing agent using foamable polyurethane resin was proposed (Japanese Patent Application Laid-open No. 100607/1983). However, it has been difficult to always obtain a constant expansion ratio with this polyurethane resin. That is, the reaction of this fixing agent consists of a curing reaction between polyol and isocyanate, which is a crosslinking agent, and a well-known foaming reaction between isocyanate and water. It has been difficult to adjust the foaming ratio because it is affected by this water content and also by the temperature inside the hole in the rock. Also, if the foaming is too fast compared to the curing reaction,
The fixing agent for rock bolts flows out of the holes in the rock, and as a result, sufficient bonding strength cannot be obtained.On the other hand, if the curing reaction is faster, the fixing agent hardens quickly and ends up not filling the holes, resulting in sufficient bonding strength. It was not possible to obtain sufficient adhesion strength.

Therefore, the present inventors have already added an acid such as an organic acid or an inorganic acid, a curing accelerator, a filler inert to the above acids, and water to an unsaturated polyester resin, and placed the mixture in a bag. We have invented a cartridge for fixing an inflatable lock bolt in which a container containing a curing agent consisting of an oxide and an acid-decomposable blowing agent consisting of a carbonate or bicarbonate is placed in a bag. When using this product, the container is broken inside the hole and all the chemicals are mixed together. The acid and acid-decomposable foaming agent are reacted to generate carbon dioxide gas, which causes the unsaturated polyester resin to foam and expand. It was warm.

In such an expandable lock bolt fixing cartridge, the foaming reaction ends when either the acid or the acid-decomposable foaming agent is consumed by the reaction, and there is an advantage that no further foaming and expansion occurs. However, when acid and water are placed together with unsaturated polyester resin, it is possible to obtain the theoretical foaming ratio when used after being stored for a relatively short period of time, about one month after mixing, but when stored for a long period of time, it comes into contact with acid. This may cause deterioration of the unsaturated polyester resin, diffusion of acid to the outside, etc., resulting in a decrease in expansion ratio.

The inventors of the present invention have investigated ways to solve these drawbacks and avoid unexpected situations where the acid used may come into contact with the installer. As a result, they added a thickener to the acid and water to make it thermosetting. The thermosetting synthetic resin, etc. is thickened to a viscosity that mixes well with the synthetic resin, and is stored in a breakable container to separate the thickened acid from the thermosetting synthetic resin or acid-decomposable foaming agent. A cartridge for fixing an expandable lock bolt that can withstand long-term storage, has appropriate expandability, and prevents acid from escaping was obtained.

That is, the expandable lock bolt fixing cartridge of the present invention is a soft synthetic resin bag filled with a base material consisting of a thermosetting synthetic resin, an acid-decomposable foaming agent, and a curing accelerator for the thermosetting synthetic resin added as necessary. A breakable container filled with a curing agent for the thermosetting synthetic resin and another breakable container filled with a thickened acid having a viscosity of 0.1 to 4000 poise at 20°C by mixing with a thickener. This is a cartridge for fixing an inflatable lock bolt, which accommodates a container that can be used.

This expansible lock bolt fixing cartridge contains a main agent consisting of a thermosetting synthetic resin, an acid-decomposable foaming agent, and a curing accelerator added as necessary;
Three components, a curing agent for thermosetting synthetic resin and an acid thickened with a thickener, are separated from each other and stored in a bag, and these components are collectively called a fixing agent. That's what it means.

Thermosetting synthetic resins that can be used in the present invention include, for example, unsaturated polyester resins and epoxy resins, which are cured by adding a curing agent to the synthetic resin before curing. When using an unsaturated polyester resin, α,β-unsaturated dibasic acids such as maleic anhydride and fumaric acid, or a part of this α,β-unsaturated dibasic acid, may be substituted with phthalic anhydride, isophthalic acid, or terephthalic acid. Styrene is an unsaturated polyester obtained by polycondensing a substance substituted with a saturated dibasic acid component such as an acid and a glycol such as ethylene glycol, dipropylene glycol, or hydrogenated bisphenol A at a molar ratio of about 1:1. , vinyltoluene,
It is dissolved in unsaturated crosslinking monomers such as chlorostyrene, divinylbenzene, diallyl phthalate, acrylic esters, and methacrylic esters, and a polymerization inhibitor such as hydroquinone is added to produce an unsaturated polyester resin before curing. .

Organic peroxides are used as curing agents for unsaturated polyester resins. An appropriate organic peroxide is used for each thermosetting synthetic resin; for example, for unsaturated polyester resins, benzoyl peroxide, cyclohexanone peroxide, tertiarybutyl hydroperoxide, etc. Benzoyl peroxide is preferred because of its ease of use. In addition, these organic peroxides should be diluted with an inorganic diluent such as talc, clay, calcium carbonate, or calcium sulfate, or an organic compound diluent such as pulp powder or diallyl phthalate powder to improve dispersibility and safety. It is also desirable from the viewpoint of

Examples of curing accelerators for unsaturated polyester resins include tertiary amines such as dimethylaniline and diethylaniline, and the amount used is 0.01 to 5 parts by weight, preferably 0.05 parts by weight, based on 100 parts by weight of the unsaturated polyester resin. ~1.0 parts by weight. If the amount is more than 5 parts by weight, storage stability will deteriorate, and if it is less than 0.01 part by weight, the curing speed of the unsaturated polyester resin will be undesirably slow.

Examples of acid-decomposable blowing agents that can be used in the present invention include carbonates or bicarbonates of alkali metals such as potassium and sodium; carbonates or bicarbonates of alkaline earth metals such as calcium; ammonium carbonate; Examples include ammonium carbonate.

Acids that can be used in the present invention include formic acid,
These are organic acids such as acetic acid, propionic acid, and lactic acid, or inorganic acids such as dilute hydrochloric acid, dilute sulfuric acid, and dilute nitric acid, and the amount used is, for example, 1 to 10 parts by weight in pure terms per 100 parts by weight of unsaturated polyester resin. It is.

As the acid thickener, an aqueous solution of a water-soluble polymer such as polyvinyl alcohol, carboxymethyl cellulose, methyl cellulose, hydroxyethyl cellulose, polyacrylamide, etc. can be used as an organic thickener. Dextrin, starch, gelatin, etc. can also be used. Inorganic thickeners such as silicic anhydride and bentonite can also be used alone or in combination with organic thickeners. Furthermore, acid-stable fillers such as barium sulfate, aluminum oxide, calcium sulfate, etc. can also be added to adjust the viscosity.

The viscosity of the acid is mainly determined by the viscosity of the base material containing the thermosetting synthetic resin used. When the viscosity of the base resin containing the thermosetting synthetic resin is low, it is naturally desirable that the viscosity of the acid is low enough to match the viscosity of the base resin.
Conversely, when the viscosity of the base resin containing a thermosetting synthetic resin is high, it is desirable that the viscosity of the acid be high. However, the viscosity can be changed as appropriate within the viscosity range of the present invention, and there are no restrictions on the combinations used.

Carbonates and bicarbonates as the acid-decomposable blowing agents mentioned above can also be used as fillers by being mixed with thermosetting synthetic resins. In other words, when carbonate or bicarbonate is added in an amount of 10 to 100 times the amount required for the reaction to the acid used, a portion will react with the acid and be used to expand the thermosetting synthetic resin, and the rest will be used to expand the thermosetting synthetic resin. It can be used as a filler for thermosetting synthetic resins. If an excess of acid-decomposable blowing agent is used relative to the acid, the foaming expansion time of the thermosetting synthetic resin will be shorter than when using an equivalent amount of acid-decomposable blowing agent to the same amount of acid. This is very advantageous, since the acid is completely consumed before the thermosetting synthetic resin hardens, ending the foaming expansion properties of the thermosetting synthetic resin and always obtaining a constant foaming expansion.

In addition to the substances added above, other fillers that do not react with acids, such as silica sand powder, glass powder, talc, clay, and barium sulfate, can be used by mixing them with the acid-decomposable blowing agent. In addition, a stabilizer for thermosetting synthetic resin and a foam stabilizer can also be added.

Next, regarding containers, thin film bags made of synthetic resin such as polyethylene, polyamide, etc. are used as thin film bags made of synthetic resin to fill the thermosetting synthetic resin, acid-decomposable foaming agent, and curing accelerator added if necessary. used. Materials for breakable containers filled with curing agents of thermosetting synthetic resins or other breakable containers filled with acids thickened by mixing with thickeners include glass tubes, ceramic tubes or synthetic resins. A thin film bag or the like is used.

Next, examples and comparative examples will be described.

Example 1 [Preparation of each component of the fixing agent] Maleic anhydride 490.5g, phthalic anhydride 740.5g
555 g of styrene was added to 1295 g of unsaturated polyester obtained by reacting 837 g of propylene glycol at 150 to 160°C, and 0.2 g of hydroquinone was added.
g was added to obtain 1850 g of unsaturated polyester resin (acid value: 30) before curing. Take 370g of this unsaturated polyester resin before curing, add 0.74g of dimethylaniline, 100g of talc, and 100g of calcium carbonate.
g. Silicone foam stabilizer (manufactured by Shin-Etsu Chemical Co., Ltd.)
F305) 1.9g was added and stirred for 30 minutes using a Shinagawa stirrer to mix uniformly, yielding 560g of the main ingredient.
The viscosity of this base agent measured with a B-type viscometer is 20 at 20°C.
It was poise.

Next, 7.1 g of benzoyl peroxide and 16.9 g of calcium carbonate were mixed to obtain 24 g of a hardening agent.

Next, add 1g of methylcellulose (400CP) to 16g of water.
Add 4g of acetic acid, mix well and dissolve.
Furthermore, 20 g of barium sulfate was added. When the viscosity after this thickening was measured using a B-type viscometer, it was found to be 20% at 20°C.
It was poise.

[Preparation of cartridge for fixing expandable lock bolt]

The main material produced as described above was used to
Loaded into a 500 mm polyamide bag, the curing agent was sealed in a glass tube with an inner diameter of 10 mm and a length of 450 mm, and acetic acid thickened with methylcellulose was placed in a glass tube with an inner diameter of 8 mm and a length of 450 mm.
It was sealed in a 450mm glass tube. These two glass tubes were inserted into the base agent in a polyamide bag filled with the base agent, and the mouth of the bag was closed to prepare a cartridge.

[Installation and pull-out test I] The above two cartridges were tested at a compressive strength of 120Kg/cm ²
In a dry sandstone upward hole (hole diameter 42 mm, hole length 2
m), and a deformed steel bar (D-25, hereinafter the same) with an outer diameter of 25 mm and a length of 2.2 m was driven while rotating.
After 3 minutes of application, the adhesive expanded to about 20 cm from the mouth. After 24 hours, the lock bolt was pulled out using a center hole type hydraulic jack, and the pullout load at that time was measured. The measurement results showed that the bolt broke at 21 tons. The expansion ratio was 2 times.

[Installation and pull-out test] Two of the above cartridges were tested with a compressive strength of 120Kg/cm ²
Upward hole drilled in sandstone (hole diameter 42mm, hole length 2m)
A deformed steel bar with an outer diameter of 25 mm and a length of 2.2 m was driven vertically into the ceiling. Three minutes after the injection, the adhesive expanded to a distance of 20 cm from the mouth.
After 24 hours, the lock bolt was pulled out using a center hole type hydraulic jack and the maximum pulling load was measured. The bolt broke under a pullout load of 22 tons. The expansion ratio was 2 times.

[Mounting and pull-out test] The above cartridge was left at room temperature for 6 months after manufacture, and then a test similar to the mounting and pull-out test was conducted. When the expansion rate was observed, the adhesive expanded to a distance of 23 cm from the mouth. Also, the bolt broke at a pullout load of 22 tons during the pullout test.

Example 2 [Preparation of each component of the fixing agent] Take 350 g of the uncured unsaturated polyester resin obtained in Example 1 and add 0.7 g of dimethylaniline, 150 g of talc, 150 g of calcium carbonate,
Add 1.8g of silicone foam stabilizer and mix using a Shinagawa stirrer.
The mixture was stirred for 30 minutes and mixed uniformly to obtain 600 g of the main ingredient.
The viscosity of the base agent measured with a B-type viscometer was 2500 poise at 20°C.

Further, 7.1 g of benzoyl peroxide and 16.9 g of calcium carbonate were mixed to obtain 24 g of a hardening agent.

Further, 16 g of water and 2 g of hydrochloric acid were added to 3 g of bentonite and 17 g of barium sulfate, and the resulting thickened acid had a viscosity of 2000 poise at 20°C.

[Preparation of cartridge for fixing expandable lock bolt]

A cartridge for fixing an inflatable lock bolt was prepared in the same manner as in Example 1.

[Installation and pull-out test] The three cartridges mentioned above had a compressive strength of 300Kg/cm ²
Upward hole with spring water in shale (hole diameter 42 mm, hole length 2
m), and a deformed steel bar with an outer diameter of 25 mm and a length of 2.2 m was driven while rotating. Approximately 5 minutes after implantation, the adhesive expanded and reached the mouth of the hole.

24 hours after driving, the lock bolt was pulled out using a center hole type hydraulic jack, and the bolt broke at a pullout load of 23 tons. Expansion magnification is 1.5
It was twice as hot.

Comparative Example 1 [Preparation of a cartridge for fixing an inflatable lock bolt] The base resin and curing agent were prepared in the same manner as in Example 1. The base resin was loaded into the same polyamide bag as in Example 1, and the curing agent was prepared in the same manner as in Example 1. It was sealed in a glass tube similar to Example 1.

Next, add a solution of 4 g of acetic acid and 16 g of water to a
It was sealed in a glass tube with a diameter of 45 cm and a length of 45 cm.

The two glass tubes described above were sealed in a polyamide bag filled with the base material to produce a cartridge for fixing an expandable lock bolt.

[Installation and pull-out test] The above-mentioned cartridge 2 was inserted into an upward hole (hole diameter 42 mm, length 2 m) drilled in sandstone with a compressive strength of 120 kg/cm ^2.
A book was inserted and a deformed steel bar was driven into it. When observed after 24 hours, the expansion of the adhesive had stopped 90 cm from the mouth. The foaming ratio was 1.2 times, and as a result of the pull-out test, the bolt came out at a pull-out load of 19 tons.

Comparative Example 2 [Preparation of a cartridge for fixing an inflatable lock bolt] The base material and hardening agent were prepared in the same manner as in Example 2. The base material was loaded into the same polyamide bag as in Example 1, and the hardening agent was prepared in the same manner as in Example 1. It was sealed in a glass tube similar to 1.

Next, add a solution of 2 g of hydrochloric acid and 16 g of water to a
It was sealed in a glass tube with a diameter of 45 cm and a length of 45 cm.

Next, the two glass tubes described above were sealed in a polyamide bag filled with the base material to produce a cartridge for fixing an expandable lock bolt.

[Installation and pull-out test] Two of the aforementioned cartridges were inserted into an upward hole (hole diameter: 42 mm, length: 2 m) drilled in a sandstone ceiling with a compressive strength of 120 Kg/cm ² , and a deformed steel bar was driven into it. 24 after driving
When observed after some time had elapsed, the foaming magnification was 1.1 times, and the adhesive stopped 100cm deep from the mouth of the hole.
Additionally, acidic water was dripping from the ceiling during the driving of deformed steel bars. The bolt came off when the pulling load was 20 tons.

As described above, the inflatable lock bolt fixing cartridge of the present invention has an appropriate expansion ratio and a high pullout load to withstand pulling out, and is sufficiently effective as an expandable lock bolt fixing cartridge. In addition, if acid is directly sealed in a container, some acid droplets will leak out after the deformed steel bar is driven without reacting with the acid-decomposable foaming agent, making it impossible to expect a sufficient expansion ratio. The cartridge for fixing the adhesive lock bolt is effective because it uses a thickened acid, so that a sufficient foaming reaction can be carried out without acid leakage.

Claims (1)

[Claims] 1. Curing of the thermosetting synthetic resin is carried out in a synthetic resin thin film bag filled with a main ingredient consisting of a thermosetting synthetic resin, an acid-decomposable blowing agent, and a curing accelerator for the thermosetting synthetic resin added as necessary. A breakable container filled with an acid and another breakable container filled with an acid whose viscosity at 20°C has been increased to 0.1 to 4000 poise by mixing the acid and a thickener are housed. Cartridge for fixing expandable lock bolts.