JPS6012520B2 - How to fix anchor bolts, etc. - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a method of drilling a hole in bedrock or concrete and inserting and fixing a rod-shaped object such as a bolt or deformed reinforcing bar into the hole.

Conventionally, as this type of fixing method, in addition to filling the gap between the rod-shaped object and the hole with cement, mortar, etc., it has been proposed to use a fixing agent for shielding bolts as shown in Figure 1. ing.

That is, the fixing agent 1 is contained in a liquid resin 3 in a glass container 2.
This is filled with granular stone aggregate 4 mixed therein, and a narrow glass tube 5 sealed with a curing agent of resin 3 is filled, and the opening is sealed with a cap 6. For example, the fixing agent 1 is inserted into the pilot hole of the anchor bolt, the anchor bolt is held in the chuck of a hand-held electric drill, inserted, rotated to crush the glass tubes 2 and 5, and then the anchor bolt is inserted. The anchor bolt is left in place and the anchor bolt is fixed as the resin hardens. This method has the advantage that the diameter of the pilot hole is small, so the drilling work is relatively easy, and it can also be applied to side walls and ceiling surfaces.
Another advantage is that the anchor bolt can be inserted and fixed deep into a fairly deep pilot hole. However, since the resin used in this conventional method is a polyester resin, it has the disadvantage that it shrinks by 3 to 7% in volume during curing.
Therefore, it lacks stability in proof strength (resistance to pull-out force) and is unreliable as a method for fixing anchor bolts and the like. Furthermore, since natural stones such as quartz sand and crystal powder are used as aggregates, the strength of the aggregates varies widely, which also causes a problem of wide variations in the fixing strength of anchor bolts. Furthermore, since a powder is used as a hardening agent, a sufficient amount of fly sand is required, but when the depth and diameter of the pilot hole become large, the simulating work is not easy. Another major problem is that the adhesive shown in FIG. 1 cannot adequately respond to changes in the diameter and depth of the pilot hole. The present invention aims to provide a method for fixing anchor bolts, etc., which eliminates the above-mentioned problems.

The outline of this invention is to provide a first material containing a solid spherical aggregate and a pasty base of a two-part mixed hardening type epoxy resin in a glass or crushable hard synthetic resin pipe, and A second member containing a solid spherical aggregate and a paste-like curing agent for the above-mentioned base is prepared, and the first and second members are inserted into prepared holes into which rod-shaped objects such as anchor bolts to be fixed are inserted. The first member is inserted first, and then the first and second members are crushed by driving the rod-shaped object, and the base material and the curing agent are mixed.

In the method of this invention, the reason for using an epoxy resin in which the base and hardening agent are in the form of a paste is that, firstly, the shrinkage during curing is extremely small, and secondly, it is suitable for ceiling surface construction. In order to prevent the resin from flowing down during the uncured period after mixing, and thirdly, to facilitate the mixing operation of the base material and the curing agent, that is, the mixing may be performed even if the mixing is not performed by a sufficient amount of sanding, for example. This is because even if the base material and the curing agent are simply stacked in a layer a few thick, it takes a relatively long time to cure reliably.

In addition, using spherical aggregate requires processing to accommodate the aggregate and paste-like material in the pipe with almost no voids when manufacturing the first and second aggregates, and this processing is not possible industrially. The first reason is to make it possible. That is, in this operation, the spherical aggregate is first filled into the pipe, and then the paste-like material is press-fitted. Since the aggregate is spherical, it has good fluidity and can be injected into the tube. When press-fitting the paste-like material, the spherical shape of the aggregate causes very little press-fit resistance compared to natural gravel, and it can be press-fitted with almost no air bubbles remaining. The second reason is that spherical aggregates can only be produced artificially, but this makes it possible to obtain aggregates with good uniformity in strength, and it is also possible to produce aggregates with good uniformity in strength. This is because it is easy. Making this spherical aggregate solid is to obtain high strength, and to prevent air bubbles and other substances that adversely affect the bonding strength from being mixed into the bonding agent when it is crushed by driving bolts during construction. It's for a reason. Preferred aggregates are ceramic balls and glass balls. The fact that these solid spherical aggregates, paste epoxy resin base, and curing agent were housed in separate tubes meant that relatively thin, long straight tubes were used to prepare the first and second members. By keeping the holes in place, you can adjust the depth by filing and folding the holes to the desired length, and by arbitrarily selecting the number of holes to adjust the diameter. This is because it can be handled.

Also, pipes other than straight lines cannot accommodate changes in the diameter of the prepared hole, but the following can be considered as ones that can accommodate changes in depth. For example, when using a spiral tube made by combining two coil-shaped tubes with an outer diameter corresponding to the lower peacock like a double-thread thread, it can be broken to an appropriate length to accommodate one depth. When using an annular tube with an outer diameter corresponding to the diameter of the pilot hole or a partially cut-out annular tube with the same outer diameter, the depth can be adjusted by selecting the quantity. In these cases, the first member and the second member are arranged alternately in the longitudinal direction of the prepared hole, or it is possible to do so by simply driving an anchor bolt or the like. It has the advantage that mixing with the agent occurs naturally.In this sense, these spiral pipes and annular pipes that are used as the first and second wall materials have a very deep surface that is difficult to manipulate from the outside. It is effective when applied to the pilot hole.
Examples will be described below.

Example 1 A ceramic ball blade with a diameter of 3 bars was placed in a glass ampoule tube 10 with a length of 15 mm, an outer diameter d of 6 ribs, and a wall thickness of 0.5 mm as shown in Fig. 2. Contain as much as possible, and add paste bisphenol A type epoxy resin 12 (
A similar glass tube 10 containing ceramic balls 10 is filled with a paste-like polyamine (hardening agent) to form a second part 14.
15 bottles of each were prepared.

The resin viscosity was 100,000 CPS for both the base and curing agent. Also, drill the concrete vertical wall to a depth of 15 mm using a 22 mm hammer drill. , 15 pilot holes with a diameter of 23 legs were drilled. Although the anchor bolt to be fixed is not shown, it has a threaded portion over its entire length, has a length of 250 mm, and has an outer diameter of 20 mm.
The ribs and material are SS41. In construction, after drilling the pilot hole 15, the inside of the pilot hole 15 is cleaned with a vacuum cleaner, and the first and second backing materials 13 and 14 are grouped into groups of six so that they are alternately positioned in the circumferential direction. Insert each anchor bolt into the five pilot holes 15 as shown in Fig. 3, insert each anchor bolt in the same way by driving it with a hammer until it reaches the bottom of the pilot hole 15, and remove the protruding material. I left it there.

In addition, 16 in FIG. 3 is a hexagonal columnar member with a length of 1 skin, which is interposed at both ends when the first and second members are put together.
It is molded with high-flow cement. In this example,
The amount of resin used to secure one bolt was 13.2 hours (
The base agent is 6.6 mm, the hardening agent is 6.6 mm), the number of ceramic balls is approximately 30 (16.2 mm), the weight of the glass tube is 19.2 mm, and the total weight is 48.6 mm. It was evening, but about 8 of these were overflowing.

Therefore, the effective usage amount is about 40 17 sakaki). Seven hours after installation, the anchor bolt was pulled out using a center hole jack (hydraulic type), and the result was 12.4 to 1.
2. In both cases, the bolts broke outside the pilot holes due to the pulling force. In addition, when we destroyed the concrete and examined the internal condition, we found that the ceramic ball was broken into two or several pieces, and the surface of the nodule-shaped adhesive part surrounding the buried part of the anchor bolt was covered with cracks. The sharp corners of the ceramic balls protruded slightly, and are thought to have been responsible for some of the anti-pulling force. Example 2 A straight glass tube with a length of 20 mm, an outer diameter of 8 Yaku, and a wall thickness of 0.5 ribs is used, and mixed ceramic balls with a diameter of 1 to 5 are placed first, and then In the same way as in Example 1, the same resin base and hardening agent were press-fitted to prepare three first members and three second members, each having a diameter of 2 squares and a depth of 3. A pilot hole with a diameter of 200 mm was drilled in rock (Katsura sandstone, average compressive strength: 820 kg/), and a deformed reinforcing bar with an outer diameter of 25 mm was fixed in the same manner as in the first example.

In a pull-out test conducted 72 hours after construction, 14.7
At t, the reinforcing bar was cut outside the pilot hole.

Example 3 As shown in Fig. 4, a willow glass tube 2 with a diameter of 8
The outer diameter of the book, which is connected to each other like a double thread screw, is approximately 27 mm.
A spiral tube 20 having a length of 25 mm was made, and one spiral tube 20a was used as a first member, and the other spiral tube 20b was used as a second member.

Mixed ceramic balls having a diameter of 1 to 5 ribs were used as the solid spherical aggregate, and the same paste base and hardening agent as in the first example were used. In construction, pilot holes with a diameter of 29 holes and a depth of 250 holes were drilled in the concrete, and deformed reinforcing bars with an outer diameter of 25 mm were fixed in the same manner as in the first example. In a pull-out test conducted 48 hours after construction, the reinforcing steel broke at 14.5.

In addition to the above examples, it was confirmed that when installed on a ceiling surface under the same conditions as the second example, a deformed reinforcing bar with a length of 400 ribs would not fall off without support immediately after installation.

In addition, in order to compare with the first example, as a result of constructing the same pilot hole and bolt as in the same example by sufficiently mixing only the same resin, the bolt came off at 5t in the pullout test after 7 hours. It was observed that the resin part was damaged.

All of the above examples were constructed in relatively shallow holes, but since construction can be done almost regardless of the depth of the hole, anchor bolts of 1 to 2 m in length are fixed to underground rock in tunnels or on steep slopes. It is highly effective when applied.

[Brief explanation of the drawing]

FIG. 1 is a vertical sectional view showing the structure of a conventional adhesive; FIG. 2 is a vertical sectional view illustrating the structure of the first and second members used in the first embodiment of the present invention; FIG. 3 is a front view of the prepared hole showing the inserted state of the first and second members of the first embodiment;
FIG. 4 is a partially sectional side view showing the spiral tube used in the third embodiment. 10...Glass tube, 11...Ceramic ball, 1
2... Epoxy resin base, 13... First member, 1
4...Second capital material, 20...2-thread spiral pipe. O' Figure 2 Figure 3 Figure 4

Claims (1)

[Scope of Claims] 1. A first member containing a solid spherical aggregate and a paste-like base of a two-part mixed hardening epoxy resin in a glass or crushable hard synthetic resin tube, and a tube similar to the above-mentioned tube. Prepare a second member containing a solid spherical aggregate and a paste-like curing agent for the base material in a pipe, and insert the first and second members into the prepared hole into which a rod-shaped object such as an anchor bolt to be fixed is inserted. A method for fixing anchor bolts, etc., in which the first and second members are first inserted, and then the rod-shaped object is driven in to crush the first and second members, and the base material and the hardening agent are mixed. 2. The method for fixing anchor bolts and the like according to item 1, wherein the tubes constituting the first and second members described in item 1 are straight tubes. 3. The tubes constituting the first and second members described in paragraph 1 are
2. The method for fixing an anchor bolt or the like according to claim 1, wherein the tube is a spiral tube having an outer diameter that can be inserted into the prepared hole described in claim 1 and coaxially assembled with each other. 4. The tubes constituting the first and second members described in paragraph 1 are
It is an annular tube having an outer diameter that can be inserted into the prepared hole described in item 1 which is annular or partially cut out, and uses a plurality of each of the above members and alternately inserts each of the above members into the prepared hole. 2. The method for fixing an anchor bolt, etc. according to claim 1, characterized by inserting the anchor bolt into a.