JP2005320755A - Waterproof sheet fixing structure in lightweight cellular concrete backing and waterproof sheet fixing construction method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To exhibit remarkable durable performance even in repetition of tensile stress caused by wind, while realizing superior initial fixation performance, by stretching a waterproof sheet over a lightweight cellular concrete backing by fastening of a machine screw. <P>SOLUTION: This waterproof sheet fixing structure fixes the waterproof sheet to the lightweight cellular concrete backing via a fixing metalfitting; and has the waterproof sheet stretched on the lightweight cellular concrete backing, the fixing metal fitting for locking the waterproof sheet on the backing, the machine screw embedded in and fixed to lightweight cellular concrete for fixing the fixing metal fitting to the backing, and a hole part formed on the lightweight cellular concrete backing for fitting and fixing the machine screw and injected with a resin material for enhancing concrete strength of the machine screw periphery by permeating into the inside lightweight cellular concrete. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

The present invention relates to fixing a waterproof sheet on a roof, a roof portion, or the like of a building, and particularly relates to a technique for fixing a waterproof sheet by screwing a roof of a lightweight cellular concrete or a roof base.

Since waterproof sheets made of resin or the like have various advantages, they are used everywhere in waterproofing work. For example, even in the so-called outer heat insulation method in which a heat insulating material is laid on the base on the roof of a building and a waterproof layer is formed on the upper surface, the waterproof layer has many advantages such as excellent workability and weather resistance. As a result, waterproof sheets made of vinyl chloride resin are widely used.

Conventionally, the fixing of the waterproof sheet to the construction surface is generally performed by screwing the waterproof sheet to the base via a mounting bracket from above the waterproof sheet.
In addition, recently, a metal fitting that is engaged with a base by a screw without opening a hole in the waterproof sheet is interposed between the base and the waterproof sheet and heated from the surface of the waterproof sheet by a high-frequency induction action. A method of melting the adhesive between the back surface and fixing the waterproof sheet to the metal fitting has been proposed, and has been implemented at many construction sites. In any of the above methods, the metal fitting is fixed to the base by screwing to the base.

However, since the lightweight cellular concrete base has a lower compressive strength than a normal concrete base, it is necessary to take necessary measures to secure a predetermined fixing force when screwing the fixing bracket.
FIG. 2 is a partial cross-sectional view showing a structure for fixing a waterproof sheet via a fixing bracket by screws, but the illustration of the waterproof sheet is omitted. In the figure, reference numeral 1 denotes a fixing bracket for pressing a waterproof sheet (not shown) to the lightweight cellular concrete base 2, and this fixing bracket 1 is lightweight by a screw 3 and a plug (resin anchor plug) 4 inserted into the hole 5. It is fixed to the cellular concrete substrate 2.

That is, the hole 5 is formed in the lightweight cellular concrete base 2, the low viscosity epoxy resin 6 is injected into the hole 5, the plug 4 is inserted into the hole 5, and then the screw 3 is screwed into the plug 4. As a result, the tip of the plug (resin anchor plug) 4 is branched and opened to strengthen the engagement between the lightweight cellular concrete and the plug, while the penetration of the epoxy resin 6 causes the hardness of the lightweight cellular concrete base 2 around the hole 5 Therefore, the engagement between the lightweight cellular concrete and the plug is further strengthened.
Techniques related to the present invention are disclosed in the following documents.
JP-A-6-58313

In the conventional fixing method as described above, the engagement between the plug / screw and the lightweight cellular concrete has a practically sufficient strength in terms of the pull-out strength of the plug / screw. That is, when a single tensile load acts on the plug / screw until the lightweight cellular concrete is destroyed, the engagement strength between the lightweight cellular concrete and the plug / screw shows a value that is not problematic in practice.
However, even if the tensile load is such that the lightweight cellular concrete does not break, sufficient strength cannot be obtained if it repeatedly acts on the plug / screw. Due to the vibration of the plug / screw, the plug / screw is pulled out and the lightweight cellular concrete around the plug / screw is weakened, and there is a problem that the predetermined strength cannot be maintained for the engagement between the lightweight cellular concrete and the plug.

  The present invention relates to a waterproof sheet fixing structure in which a waterproof sheet is screw-fixed to a lightweight cellular concrete base via a fixing metal fitting, the waterproof sheet stretched on the lightweight cellular concrete base, and the waterproof sheet as a base A fixing metal fitting to be fixed to the base, a screw embedded and fixed in the lightweight cellular concrete for fixing the fixing metal to the ground, and an internal lightweight cellular concrete formed in the lightweight cellular concrete base for fitting and fixing the screw. It is intended to solve the above-mentioned conventional problems by comprising a hole into which a resin material that penetrates into the resin and enhances the concrete strength around the screw is injected.

  Moreover, in the fixing structure of the waterproof sheet on the lightweight cellular concrete base, the diameter of the hole and the valley diameter of the screw are substantially the same, while the resin material injected into the hole is a low-viscosity resin material. Sometimes.

Furthermore, in the fixing structure of the waterproof sheet on any one of the lightweight cellular concrete bases, the screw may have a configuration in which the volume V between one pitch and the volume C in the circumferential direction of the screw are in the relationship of the following formula 1.
Formula 1: C / V> 0.7

Furthermore, this invention solves the said conventional subject by providing the waterproof sheet fixing construction method in the lightweight cellular concrete which consists of the following processes.
(A) forming a screw fitting hole at a predetermined position on the lightweight cellular concrete base;
(B) Injecting a resin material into the hole,
(C) Next, a step of fixing the fixing bracket to the lightweight cellular concrete base by screwing the screw into the hole,
(2) A process in which a waterproof sheet is stretched on a lightweight cellular concrete base and the waterproof sheet is fixed to the base via a fixing bracket.

Further, in the waterproof sheet fixing method in the lightweight cellular concrete described above, the diameter of the hole and the valley diameter of the screw are substantially the same, while the resin material injected into the hole is composed of a thermoplastic low-viscosity resin material. There are things to do.

Furthermore, in the fixing method of the waterproof sheet on any one of the lightweight cellular concrete bases, the screw may have a structure in which the volume V between one pitch and the volume C in the circumferential direction of the screw are in the relationship of the following formula 1.
Formula 1: C / V> 0.7

With the above configuration, in the structure in which the waterproof sheet is fixed to the lightweight cellular concrete base by screwing, it has sufficient strength against the tensile load related to the screw, and even if the tensile load repeatedly acts, Ensuring a strength that does not hinder the practical use of the engagement, and enables stable fixing of the waterproof sheet on the lightweight cellular concrete base for a long period of time.

  The diameter of the hole formed in the lightweight cellular concrete base is approximately the same as or slightly larger than the valley diameter of the screw, so that a good tendency can be obtained in the engagement strength between the screw and the hole. Uses a low viscosity epoxy adhesive.

FIG. 1 is a cross-sectional view showing one embodiment of a waterproof sheet fixing structure according to the present invention.
In the figure, reference numeral 1 denotes a fixing bracket for pressing the waterproof sheet 7 to the lightweight cellular concrete substrate 2, and the fixing bracket 1 is fixed to the lightweight cellular concrete substrate 2 by screws 3 inserted into the holes 5. That is, a hole 5 is formed in the lightweight cellular concrete base 2, a low viscosity epoxy resin 6 is injected into the hole 5, and then the screw 3 is screwed along the hole 5. The epoxy resin 6 penetrates into the lightweight cellular concrete on the inner surface of the hole 5, thereby improving the hardness of the lightweight cellular concrete around the hole 5 or expressing the toughness. The peaks will be tightly screwed into the reinforced lightweight cellular concrete. In the figure, reference numeral 7 denotes a vinyl chloride sheet as a waterproof sheet, which is joined to the fixture 2 with an adhesive.

The screw 3 used in this embodiment has a normal threaded portion, the valley diameter is 5.00 mm, the peak diameter is 7.2 mm, and the length is 50 mm. The hole corresponding to this screw 3 No. 5 has a diameter of 5.00 mm and a depth of 60 mm. The resin material to be injected into the hole 5 is desirably in a viscosity range of about 100 to 2000 mPa · s (23 degrees Celsius) in order to ensure high permeability to lightweight cellular concrete. In this embodiment, 500 ± 200 mPa・ Use s.

In the above embodiment, a commercially available type of screw is used as the screw 3, but “self-screwing screw for lightweight cellular concrete” according to 1994 Patent Application Publication No. 78864 is used as the screw 3. You can also Theoretically, the degree of coupling between the screw 3 and the lightweight cellular concrete is higher by adopting this screw.

Next, the test results regarding the strength of the embedded screw in the waterproof sheet fixing structure according to the embodiment of the present invention, that is, the engagement (bonding) strength between the screw and the hole portion formed in the lightweight cellular concrete will be described. In each test, a simple tensile test and a repeated fatigue test were performed.
Test example a
Simple tension test: Measures the maximum strength by simple tension. Test speed: 10mm / min.
Repeated fatigue test: Repeated fatigue with a load of 0-200kgf (Test speed: 10mm / min.)
And a simple tensile test after 1000 cycles of repeated fatigue.

The specifications for the lightweight cellular concrete hole are as follows.
Screw: A commercially available product with a peak diameter of 7.2 mm, a valley diameter of 5.00 mm and a length of 50 mm.
Hole: Diameter 5.00mm, depth 60.00mm
Resin material to be injected into the hole: Epoxy adhesive with a viscosity of 500 ± 200 mPa · s (23 degrees Celsius).
The test was conducted three times with the above contents.
Exam 1
Fatigue test: No abnormality after 1000 cycles.
The simple tensile strength after the fatigue test was 392 kgf, and a large breakage occurred in the lightweight cellular concrete around the screw.
Test 2
Fatigue test: No abnormality after 1000 cycles.
The simple tensile strength after the fatigue test was 358 kgf, and a large breakage occurred in the lightweight cellular concrete around the screw.
Test 3
Fatigue test: No abnormality after 1000 cycles.
The simple tensile strength after the fatigue test was 329 kgf, and a large breakage occurred in the lightweight cellular concrete around the screw.

Test b
Under the same conditions as in Test Example a except that the screw in Test Example a was replaced with “Self-Screw Screw for Lightweight Aerated Concrete” according to Claim 3 of Patent Application Publication No. 78864, 1994. The test was performed twice.
Exam 1
Fatigue test: No abnormality after 1000 cycles.
The simple tensile strength after the fatigue test was 325 kgf, and a large breakage occurred in the lightweight cellular concrete around the screw.
Test 2
Fatigue test: No abnormality after 1000 cycles.
The simple tensile strength after the fatigue test was 358 kgf, and a large breakage occurred in the lightweight cellular concrete around the screw.

Subsequently, in order to compare with the test result of the present invention, a strength test was performed on the above-described conventional example. The load conditions on the fixing part between the screw and the hole are the same as in the above test example.
The specifications for the lightweight cellular concrete hole are as follows.
Screws / plugs: Commercially available screws with a length of 50 mm and a crest diameter of 4.5 mm.
Hole: 6.00mm diameter, 40.00mm depth
Resin material to be injected into the hole: Epoxy adhesive with a viscosity of 500 ± 200 mPa · s (23 degrees Celsius).

The test was conducted three times with the above contents.

Test 1
Fatigue test: The lightweight aerated concrete around the resin anchor plug was broken into powder in 70 cycles, and the resin anchor plug slipped out. A simple tensile test after 1000 cycles of the fatigue test was not possible.
Test 2
Fatigue test: While the lightweight cellular concrete around the resin anchor plug was broken into powder in 122 cycles, the resin anchor plug slipped out, and a simple tensile test after 1000 cycles of the fatigue test was not possible.
Exam 3
Fatigue test: While the lightweight cellular concrete around the resin anchor plug was broken into powder in 132 cycles, the resin anchor plug slipped out, and a simple tensile test after 1000 cycles of the fatigue test was not possible.

  As is clear from the comparison of the above test results, the present invention has a remarkable improvement in the engagement (bonding) strength between the screw and the hole in the lightweight cellular concrete as compared with the prior art, that is, the screw is reinforced with a resin material. Since it is screwed into the lightweight cellular concrete hole with increased rigidity, the waterproof sheet fixing structure on the lightweight cellular concrete substrate is extremely good for the tensile action that occurs irregularly and repeatedly over the long term due to wind and other factors. It can be said that it has durability performance.

It is sectional drawing which shows one Example of the fixing structure of the waterproof sheet in the lightweight cellular concrete base | substrate which concerns on this invention. It is sectional drawing which shows a prior art.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Fixing metal fixture 2 Lightweight cellular concrete base 3 Screw 4 Plug 5 Hole 6 Resin material 7 Waterproof sheet

Claims (6)

A waterproof sheet fixing structure in which a waterproof sheet is screw-fixed to a lightweight cellular concrete base via a fixing bracket, and the waterproof sheet stretched on the lightweight cellular concrete base and the waterproof sheet are locked to the base A fixing bracket, a screw embedded and fixed in a lightweight cellular concrete to fix the fixing bracket to the ground, and a lightweight cellular concrete formed in the lightweight cellular concrete base to fit and fix the screw to penetrate inside the lightweight cellular concrete A structure for fixing a waterproof sheet on a lightweight cellular concrete base comprising a hole filled with a resin material for enhancing the concrete strength around a screw. 2. The waterproof sheet fixing structure in the lightweight cellular concrete substrate according to claim 1, wherein the diameter of the hole and the valley diameter of the screw are substantially the same, while the resin material injected into the hole is a low-viscosity resin material. A waterproof sheet fixing structure on a lightweight cellular concrete base. 3. The waterproof sheet fixing structure according to claim 1 or 2, wherein the screw has a volume V between one pitch and a volume C in the circumferential direction of the screw in a relation of the following formula 1. Waterproof sheet fixing structure on lightweight cellular concrete substrate.
Formula 1: C / V> 0.7 Waterproof sheet fixing method for lightweight cellular concrete consisting of the following processes.
(A) forming a screw fitting hole at a predetermined position on the lightweight cellular concrete base;
(B) Injecting a resin material into the hole,
(C) Next, a step of fixing the fixing bracket to the lightweight cellular concrete base by screwing the screw into the hole,
(2) A process in which a waterproof sheet is stretched on a lightweight cellular concrete base and the waterproof sheet is fixed to the base via a fixing bracket. The waterproof sheet fixing method for lightweight cellular concrete according to claim 4, wherein the diameter of the hole and the valley diameter of the screw are substantially the same, while the resin material injected into the hole is a low-viscosity resin material. A waterproof sheet fixing method on a lightweight lightweight concrete base. The waterproof sheet fixing method for a lightweight cellular concrete substrate according to claim 4 or 5, wherein the screw has a volume V between 1 pitch and a volume C in the circumferential direction of the screw in the relationship of the following formula 1. Waterproof sheet fixing method for lightweight cellular concrete substrate.
Formula 1: C / V> 0.7

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