JPH0823275B2 - Adhesive for fixing bolts - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a bolt fixing adhesive used to fix a bolt by filling a hole provided in a foundation such as a concrete foundation or a rock.

(Prior Art) Conventionally, as a method for fixing bolts such as anchor bolts and screw bolts to a base, a capsule containing a bolt fixing adhesive is inserted into a hole formed in the base, and the inside of the hole is fixed. A method in which a bolt fixed to an agitator is inserted into the capsule and the bolt is rotated to break the capsule so that the adhesive contained in the capsule causes mixing and reaction in the hole, and the bolt is fixed to the hole by the adhesive. Has been proposed (see, for example, JP-A-55-1295529 and JP-B-62-21960).

The capsule is configured by accommodating a liquid resin and an inner container in which a curing agent is enclosed in an outer container, and sealing the opening of the outer container with a cap. Also, by destroying the inner container, the liquid resin and the curing agent are mixed and reacted. Therefore, the fixing agent for fixing bolts is required to have a fixing strength for fixing the bolt to the base with a predetermined strength or more, as well as the stirring property when the bolt is rotated in the hole by the stirring device and the inside of the outer container. Workability etc. when inserting aggregate is required.

Conventionally, as such a fixing agent for bolt fixing, Japanese Patent Publication No. 62-21960 described above, a liquid resin, a curing agent,
An adhesive composed of a magnesia clinker as an aggregate is disclosed, and Japanese Patent Publication No. 59-21440 and Japanese Patent Publication No. 60-12520 disclose an artificial solid spherical aggregate, a paste-like cold-setting resin, and a paste. A fixing agent comprising a curing agent of

(Problems to be solved by the invention) As described above, the adhesive agent using the magnesia clinker as an aggregate is a hard material, so when the bolt is inserted into the hole and the adhesive agent is stirred. ,
There is a drawback that the repulsive force received from the adhesive agent becomes large and the labor of the worker becomes high. Moreover, since the shape of this aggregate is not spherical, the aggregates do not slide well, and when filling the inside of the container, the aggregate causes a bridge phenomenon near the opening of the container, significantly reducing the filling work. I have something to do.
Further, since the aggregate and the liquid resin are poorly mixed, there is a drawback that the fixing strength and workability are likely to vary.

In addition, as described above, the adhesive agent using the solid spherical aggregate as the aggregate has little variation in the adhesive strength, the labor of the operator is relatively low, and the filling work of the aggregate into the container is easy. The advantage is that However, since the settling speed of the solid spherical aggregate with respect to the pasty liquid resin and the curing agent is slow, there is a drawback that the productivity of this adhesive agent is poor.

The present invention is to solve the above-mentioned drawbacks, and an object of the present invention is to improve productivity by using an aggregate having a high sedimentation rate, and to reduce the labor of a construction worker and shorten the construction time. At the same time, it is to provide a fixing agent for fixing bolts with less variation in construction time. Another object of the present invention is to provide a fixing agent for fixing bolts which can exhibit stable fixing performance.

(Means for Solving the Problems) A bolt fixing adhesive of the present invention is a bolt fixing adhesive containing a liquid resin, an aggregate and a curing agent, and the aggregate is
SiO ₂ and Al ₂ O ₃ consisting of a fired product as a main component, the bulk specific gravity of the aggregate is 2.0 to 3.2, and the content of SiO ₂ in the aggregate is 40
It is characterized by being in the range of wt.% To 98 wt.%, Whereby the above object is achieved.

The liquid resin is preferably a resin that is mixed with a curing agent and can be cured at room temperature, and examples thereof include unsaturated polyester resins and epoxy resins. The liquid resin preferably has a viscosity at 20 ° C. of 500 to 2000 cps.

As the curing agent, one that can cure the liquid resin at room temperature is generally used. When unsaturated polyester resin is used as the liquid resin, the curing agent is benzoyl peroxide (BPO), lauroyl peroxide (LP
Organic peroxides such as O) and methyl ethyl ketone peroxide (MEKPO) are preferably used, and powders of these peroxides diluted with an inorganic filler are particularly preferable. Also,
When an epoxy resin is used as the liquid resin, polyamine, polyamidoamine, polymercaptan and the like are preferably used as the curing agent.

The above-mentioned aggregate is composed of a fired product (referred to as a ceramic ball) whose main components are SiO ₂ and Al ₂ O ₃ , and the bulk specific gravity of the aggregate is
2.0 to 3.2, and the content of SiO _{2 in} the aggregate is 40% by weight
~ 98% by weight is used. By using such an artificial fired product as the aggregate, it is possible to secure the uniformity of the fixing performance and the working performance without variation in the particle diameter of the aggregate and the apparent specific gravity. Also, since the fired product is a solid sphere, when filling this aggregate into the outer container,
The aggregate does not cause a bridging phenomenon at the opening of the outer container. When an aggregate having a bulk specific gravity of less than 2.0 is used, the productivity of the adhesive agent decreases because the sedimentation rate to the liquid resin is slow, and conversely, when an aggregate having a bulk specific gravity of more than 3.2 is used. Is
Since the aggregate is inevitably hard, the operator's labor in placing the adhesive in the holes of the base becomes great. Further, when the content of SiO _{2 in} the aggregate is less than 40% by weight, the content of Al ₂ O ₃ becomes relatively large and the hardness of the aggregate becomes too hard. Construction takes a long time,
Moreover, the degree of labor of the builder increases. When the content of SiO _{2 in} the aggregate exceeds 98% by weight, the content of Al ₂ O ₃ becomes less than 2% by weight, and the hardness of the aggregate becomes too soft. The mixing property of is reduced.

The above-mentioned aggregate is preferably added in an amount of 60 to 300 parts by weight, more preferably 100 to 200 parts by weight, based on 100 parts by weight of the liquid resin. If the amount of the aggregate added is less than 60 parts by weight with respect to 100 parts by weight of the liquid resin, the pot life (workable time) becomes too short, and if it exceeds 300 parts by weight, the work time becomes too long.

The present invention will be specifically described below based on examples.

Examples 1 and 2 and Comparative Examples 1 to 4 In a glass container (outer tube) having an outer diameter of 13 mm, a wall thickness of 0.7 mm and a length of 85 mm, an unsaturated polyester resin (viscosity 3000 cps.
eguval K-27 made by Bayer) is weighed 4.0 cc, and benzoyl peroxide diluted to 30% with an inorganic filler is enclosed in the outer tube. Outer diameter 5.0 mm, wall thickness 0.5 mm, length 70 mm The glass container (inner tube) of was inserted. Next, an adapter was attached to the opening of the outer tube so that the aggregate would not overflow, and 6 g of aggregate, which had been sized to 2 to 4 mm in advance, as shown in Table 1, was introduced. After filling the outer tube with all the aggregates, the glass container was lightly flipped at intervals of once per second to give vibration, and the time until all the aggregates completely sink into the liquid resin was measured 5 times each. The range is shown in Table 1. The measurement was performed at 20 ° C.

As shown in Table 1, when crushed stone and river gravel are used as aggregates as in Comparative Examples 1 and 2, the sedimentation rate is very slow and the productivity is poor. On the other hand, in Examples 1 and 2 and Comparative Examples 3 and 4 in which the ceramic balls were used as the aggregate, it was found that the sedimentation time of the aggregate was short and the variation in the time required for sedimentation was small.

Examples 3 and 4 and Comparative Examples 5 to 9 Similarly to Example 1, the outer tube was filled with the liquid resin, the inner tube and the aggregate shown in Table 2, and the opening of the outer tube was sealed with a plastic cap. Then, an adhesive capsule for fixing bolts was prepared.

On the other hand, a hole having a diameter of 15 mm and a depth of 100 mm was drilled in a concrete block having a compressive strength of 240 kg / cm ² , and the capsule was inserted into this hole. Next, set all screw bolts with an outer diameter of 12 mm and a length of 150 mm (45 ° bevel tip) on a hammer drill (PR-50 300 rpm made by Hitachi Koki Co., Ltd.), and rotate the bolts while only using the weight of the hammer drill. Was placed in the hole, and the time required for embedding the bolt in the hole was examined three times, and the value is shown in Table 2.

As shown in Table 2, in Examples 3 and 4 and Comparative Examples 8 and 9 in which the ceramic balls having a substantially perfect spherical shape were used, the apparent specific gravity of the aggregate was constant, so that the casting time was almost varied. Absent. Since the aggregates used in Comparative Examples 5, 6, and 7 are not spherical, there is a large variation in the placing time. In addition, since the aggregates used in Comparative Examples 5 and 9 are hard, the vibration of the hammer drill at the time of placing was extremely severe, and the labor of the operator was considerably high.

Examples 5 and 6 and Comparative Examples 10 to 13 A bolt-fixing adhesive capsule prepared in the same manner as in Example 3 was inserted into a hole having a diameter of 15 mm and a depth of 100 mm opened in a concrete block having a compressive strength of 240 kg / cm ^2. did. Next, all screw bolts having an outer diameter of 12 mm and a length of 150 mm (45 ° beveled tip) were placed with a hammer drill. Then, the maximum pulling load of the bolt after curing for 3 hours was measured 3 times, and the value is shown in Table 3.

As shown in Table 3, when natural aggregate is used, the maximum strength varies greatly. From the results of Table 2, it can be seen from the results of Table 2 that the fixing time using the natural aggregate is not constant, the mixing of the liquid resin and the curing agent becomes insufficient, and the dispersion state of the aggregate in the resin cured product. Is also likely to be non-uniform. When using ceramic balls, the maximum tensile strength is higher and the variation is less than when using natural aggregate. In Comparative Example 13, since the aggregate was not crushed and the screw threads of the bolt were crushed to reduce the effective bonding area, adhesive failure was likely to occur at the bolt interface, and the fixing strength was sometimes significantly reduced.

(Effect of the invention) As described above, since the present invention uses the calcined material containing SiO ₂ and Al ₂ O ₃ as the main components as the aggregate, there is little variation in the bonding strength, and the aggregate content in the container is small. Filling work can be done easily. Further, since the bulk specific gravity of the aggregate is 2.0 to 3.2, and the content of SiO _{2 in} the aggregate is 10% by weight to 98% by weight, the sedimentation speed of the aggregate into the liquid resin is relatively fast, There is no loss of productivity. In addition, it is possible to reduce the labor of the construction worker, improve the construction workability, shorten the construction time, and reduce the variation in the construction time. Furthermore, since the fired product has a uniform composition and is spherical and has a substantially constant apparent specific gravity, the mixed state at the time of construction becomes uniform, and stable fixing performance can be obtained.

Claims (1)

[Claims] 1. A bolt fixing adhesive containing a liquid resin, an aggregate and a curing agent, wherein the aggregate comprises a fired product containing SiO ₂ and Al ₂ O ₃ as main components, and the bulk specific gravity of the aggregate is Is 2.0 to 3.2, and the content of SiO _{2 in} the aggregate is 40% by weight to 98% by weight.