Template peeling test method and template peeling test body

Abstract

To prevent a simulated foundation concrete from being lifted together with a template and the precast template from being cracked in a template peeling test.SOLUTION: The template peeling test method of the present invention includes a test preparation step of curing the simulated foundation concrete in a state where the template 10 is buried in the simulated foundation concrete 20, and a peeling step of peeling off the template 10 from the simulated foundation concrete 20 by lifting the template 10 by screwing the peeling bolt 2 downward relative to the template 10 in a state where the peeling bolt is screwed from the upper side into the nut 11 penetrating the template 10 in the thickness direction and the lower end of the peeling bolt 2 abuts on the descent restraint member 5 provided in the simulated foundation concrete 20 so as not to descend.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] This invention relates to a test method for a peel test to check the degree of adhesion between a building / civil engineering template embedded in foundation concrete and the foundation concrete, and to a test specimen used for this test. [Background technology]

[0002] Templates with positioning through-holes for inserting anchor bolts or main reinforcement bars into steel or concrete plates are widely used to position the bolts for attaching seismic isolation elements in seismically isolated buildings, anchor bolts for steel columns in general buildings, and main reinforcement bars (rebars) in reinforced concrete buildings. Such templates must adhere closely to the underlying foundation so that they do not peel off from the underlying foundation in the event of an earthquake, and template peeling tests are conducted using templates that have been constructed in advance using the same construction method.

[0003] Conventionally, in this peel test, as shown in FIG. 7, a template 910 is suspended at four points by wires W, lifted by a crane (not shown), and peeled off from the simulated concrete foundation 20. Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the conventional pull-off test described above, if the mock foundation concrete is not fixed to the floor surface, the mock foundation concrete will lift up along with the template, and if the template is made of precast concrete, if it is hung at four points, bending stress acts on the template because the direction of the wires is not parallel to the thickness direction of the template, causing the template to crack due to the brittleness of the concrete. The present invention has been made in consideration of the above problems, and aims to provide a template pull-off test method and template pull-off test specimen that prevent the mock foundation concrete from lifting up even when the mock foundation concrete is not fixed to the floor surface and that is less likely to crack even if the template is made of concrete. [Means for solving the problem]

[0005] The invention made to solve the above problem is a template peeling test method in which a plate-shaped template equipped with a nut penetrating in the thickness direction is embedded horizontally with its top surface exposed in unhardened mock foundation concrete, and after the mock foundation concrete has hardened, the template is lifted up to peel off the template from the mock foundation concrete, thereby confirming the degree of adhesion between the template and the mock foundation concrete. The template peeling test method of the present invention is characterized by comprising a test preparation step of hardening the mock foundation concrete with the template embedded in the mock foundation concrete, and a peeling step of threading a peeling bolt through the nut from above, bringing the lower end of the peeling bolt into contact with a downward restraint member installed in the mock foundation concrete so that it cannot be lowered, and then screwing the peeling bolt downward relative to the template to lift the template and peel it off from the mock foundation concrete.

[0006] In the template peel test method of the present invention, the lower end of the peeling bolt, which is threaded into the upper side of the template nut, is abutted against a descent restraint means that prevents it from descending, and the peeling bolt is then screwed in. The peeling bolt threads into the template, causing its lower end to protrude from the underside, but because the lower end of the peeling bolt abuts against the descent restraint means and the bolt cannot descend, the template is raised relative to the simulated foundation concrete by the amount of the protruding peeling bolt. In this way, the template is peeled from the simulated foundation concrete.

[0007] In this case, the stripping bolt applies an upward force to the template while applying a downward force to the mock foundation concrete, so the mock foundation concrete does not lift up along with the template. Also, because the stripping bolt can apply a force to the template in a direction perpendicular to its thickness, it is possible to suppress the application of bending stress to the template, which prevents cracking even if the template is made of precast concrete.

[0008] In the template peeling test method of the present invention, the test preparation step includes a template placing step of screwing the peeling bolt into the female threaded hole of the nut from above and extending the male threaded portion from below the nut so that a long nut is partially screwed onto the male threaded portion from below, and placing the template in a formwork for molding simulated foundation concrete; a concrete pouring step of pouring the simulated foundation concrete; and a shaft inserting step of removing the peeling bolt and then inserting a shaft made of a rod-shaped member into the female threaded hole of the long nut, and it is preferable that the template peeling step includes using the shaft as the descent restraint member and abutting the lower end of the peeling bolt against the shaft before the peeling bolt is screwed into the long nut. In this way, by connecting the stripping bolt, the cut bolt, and the nut in the template assembly process, they can be installed simultaneously and integrally within the formwork for the simulated foundation concrete in the template placement process. Then, in the shaft insertion process, when a rod-shaped shaft is inserted into the nut, the lower end of the shaft abuts against the cut bolt, thereby restricting its descent. In the template peeling process, by abutting the lower end of the stripping bolt against the shaft before threading the stripping bolt into the nut as a descent restraint member, the stripping bolt is not connected to the nut. Therefore, by screwing the turning bolt and protruding it downward relative to the template, the template can be lifted from the simulated foundation concrete by that amount.

[0009] The present invention includes a template peeling test specimen comprising a plate-shaped template with a nut penetrating through it in the thickness direction, simulated foundation concrete in which the plate-shaped template is embedded, a stripping bolt that is threaded through the long nut from above, and a descent restraint member that is arranged in the simulated foundation concrete so as not to be able to descend, abuts against the lower end of the stripping bolt, and restrains the descent of the stripping bolt as it threads downward.

[0010] The template peeling test specimen of the present invention preferably comprises a long nut that is screwed from below onto a peeling bolt that is threaded through the nut, and a cut bolt that is screwed partway into the female threaded hole of the long nut from below, and the descent restraint member is composed of a shaft of a rod-shaped member that is inserted into the female threaded hole of the long nut from above and whose descent is restrained by the cut bolt, and the peeling bolt that is screwed into the nut from above abuts against the shaft before being screwed into the long nut. [Effects of the Invention]

[0011] As described above, the template peel test method and template peel test specimen of the present invention can prevent the simulated foundation concrete from lifting up along with the template. Furthermore, even if the template is precast, it can be prevented from cracking when lifted. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 is a plan view showing a template peel test piece according to a first embodiment of the present invention. [Figure 2] FIG. 2 is a cross-sectional view taken along line XX in FIG. [Figure 3] FIG. 2 is an explanatory view showing how the template peeling test specimen shown in FIG. 1 is prepared before the template peeling test. [Figure 4] FIG. 4 is an explanatory diagram showing a state in which a template peeling test is performed after the preparation of FIG. 3 is completed. [Figure 5] FIG. 10 is a cross-sectional side view showing a template peel test piece according to a second embodiment of the present invention. [Figure 6] FIG. 10 is a cross-sectional side view showing a template peel test piece according to a third embodiment of the present invention. [Figure 7] FIG. 1 is an explanatory diagram showing a conventional template peeling test. DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings. However, the present invention is not limited to the following embodiment, and various modifications can be made without departing from the spirit and scope of the present invention.

[0014] (First embodiment) FIG. 1 shows a template peel test specimen 100 according to a first embodiment of the present invention. The template peel test specimen 100 is a replica of a template used to position mounting bolts that attach a vibration isolation device equipped with vibration isolation rubber to foundation concrete, and the template peel test of this embodiment is carried out to confirm the adhesion between the template and the foundation concrete. However, the present invention is not limited to vibration isolation devices, and can be widely used for peel tests of templates used to position anchor bolts for steel columns in general buildings, main column reinforcement (reinforcing bars) in reinforced concrete buildings, etc.

[0015] (Template peel test specimen) As shown in Figures 1 and 2, the template peeling test specimen 100 comprises a template 10, a mock foundation concrete 20 in which the template 10 is embedded, a plurality of peeling bolts 2, 2, ... used to peel the template 10 from the mock foundation concrete 20, a long nut 3 and a cut bolt 4 embedded in the mock foundation concrete 20 to support the template 10 from below, and a rod-shaped shaft (descent restraint member) 5 housed within the long nut 3.

[0016] As shown in Figures 1 and 2, the template 10 comprises a disk-shaped template body 1 and a plurality of nuts 11 (12 in the illustrated example) that penetrate the template body 1 in the thickness direction and are arranged at equal intervals along the periphery of the template body 1.

[0017] The template body 1 is made of precast concrete and, as shown in Figure 1, has a somewhat large-diameter circular hole 12 in the center, numerous small holes 13,... arranged at equal angular intervals in two circular shapes on the inside and outside of the diameter of the template body 1, and bottom end reinforcement bars 14,... embedded near the bottom end so as to cross vertically and horizontally while avoiding the nuts 11. The circular hole 12 in the center of the template body 1 is used to pour concrete to be poured for the simulated foundation concrete 20, and the small holes 13,... are used to let air escape from below the template body 1 when this concrete is poured.

[0018] 3, the nut 11 has an internal threaded hole 11a penetrating in the axial direction, two flanges 11b, 11b embedded in the template body 1 flush with the upper surface 1a and the lower surface 1b thereof, and a leg 11c extending downward from the lower surface 1b of the template body 1. The leg 11c is embedded in the simulated foundation concrete 20.

[0019] The peel bolt 2 is a hexagonal bolt, and as shown in Figure 3(a), before the peel test is conducted, it is threaded into the female screw hole 11a of the nut 11 from above until the head 2a abuts against the nut 11, and the tip side of the male screw portion 2b protrudes downward from the lower opening of the nut 11.

[0020] The long nut 3 is cylindrical and has a female screw hole 3a on the inner surface with the same female thread as the nut 11. As shown in Figure 3(a), before the pull-off test is conducted, the long nut 3 is screwed onto the male screw portion 2b of the stripping bolt 2 that protrudes below the nut 11 until its upper end abuts against the lower end of the nut 11.

[0021] As shown in Figure 3(a), the cut bolt 4 is connected to the nut 3 by threading its upper end into the female screw hole 3a from below the nut 3. A circular annular anchoring plate 41 is threaded and welded near the lower end of the cut bolt 4 to prevent the nut 3 and the cut bolt 4 from slipping out of the simulated foundation concrete 20.

[0022] The shaft 5 is made of a round bar (rod-shaped member) made of metal such as stainless steel, and as shown in Figure 4(a), its lower end is abutted against the upper end of the cut bolt 4, making it unable to descend. When the shaft 5 is housed in the long nut 3, its upper end extends into the nut 11.

[0023] (Template peeling test method) Next, a template peeling test method according to this embodiment will be described. The template peeling test method according to this embodiment is performed using a template peeling test specimen 100, and includes a test preparation step S1 in which the template 10 is embedded in the simulated foundation concrete 20 and the simulated foundation concrete 20 is hardened, and a peeling step S2 in which the template 10 is lifted and peeled off from the simulated foundation concrete 20.

[0024] In the template peel test of this embodiment, the template body 1 can be made of steel plate, concrete, or mortar, but is particularly suitable for templates made of concrete or mortar, which are prone to cracking due to bending stress. Furthermore, the template peel test of the present invention can be applied to template body 1 that is circular as shown in FIG. 1, or that has a square, circular, or rectangular ring shape.

[0025] (Test preparation process S1) The test preparation process S1 is a process of hardening the simulated foundation concrete 20 with the template 10 embedded in the simulated foundation concrete 20. The test preparation process S1 includes a template assembling process S11, a form assembling process S12, a template placing process S13, a concrete pouring process S14, and a shaft inserting process S15.

[0026] (Template assembly process S11) As shown in FIG. 3( a), the template assembly process S11 is a process of connecting the cut bolt 4 supporting the template 10 to the lower end of the nut 11 via the stripping bolt 2 and the long nut 3. In the template assembly process S11, the stripping bolt 2 is first threaded into the female threaded hole 11a of the nut 11 from above until its head 2a abuts the top surface of the nut 11, causing the tip of the male threaded portion 2b of the stripping bolt 2 to protrude from the underside of the nut 11. Next, the long nut 3 is threaded onto the tip of the male threaded portion 2b of the stripping bolt 2 until its upper end abuts the lower end of the nut 11. At this time, the male threaded portion 2b of the stripping bolt 2 is threaded partway into the female threaded hole 3a of the long nut 3 from above. Next, the cut bolt 4, to which a fixing plate 41 has been previously welded, is threaded into the female threaded hole 3a of the long nut 3 from below.

[0027] (Formwork assembly process S12) The formwork assembly process S12 is a process of assembling a formwork 8 used for pouring the simulated foundation concrete 20. The formwork 8 is assembled in parallel with or before or after the template assembly process S11. The formwork 8 has four side walls 81, each made of concrete panels reinforced with square timbers, and a bottom wall 82. Because the formwork 8 has the bottom wall 82, the simulated foundation concrete 20 is formed independently from the on-site slab surface, etc. The reinforcement 21 is made up of a number of U-shaped main reinforcements 21a, arranged vertically and horizontally in a lattice pattern, and the periphery is reinforced with multiple peripheral reinforcements 21b, on the top and bottom. The reinforcement 21 is simply placed on the bottom wall 82 of the formwork 8 and is not fixed to the bottom wall 82.

[0028] (Template placing step S13) After the assembly of the template 10 and formwork 8 in steps S11 and S12 is completed, the template 10 is placed inside the formwork 8. As shown in Figures 1 and 2, the template 10 is placed by passing the cut bolts 4 between the reinforcement bars 21 inside the formwork 8 and bringing the lower ends of the cut bolts 4 into contact with the bottom wall 82 of the formwork 8, thereby adjusting the level of the template body 1. Some of the cut bolts 4 (four in the example of Figure 2) are welded with level adjustment nuts 42 that rotate the long nuts 3 to adjust the length of the cut bolts 4 protruding from the long nuts 3, thereby adjusting the level of the template body 1.

[0029] (Concrete pouring process S14) After the template placing step S13 is completed, ready-mixed concrete is poured into the circular hole 12 in the center of the template body 1 to cast the mock foundation concrete 20 into the formwork 8. The mock foundation concrete 20 is cast so that the upper surface 1a of the template body 1 and the upper surface 1a of the mock foundation concrete 20 are flush with each other.

[0030] (Shaft insertion process S15) Once the simulated foundation concrete 20 has solidified, as shown in Fig. 3(b), the stripping bolt 2 is removed from the nut 11 and the long nut 3, and as shown in Fig. 3(c), the shaft 5 is inserted from above the nut 11 into the female screw hole 11a of the nut 11 and the female screw hole 3a of the long nut 3. This completes the test preparation step S1.

[0031] (Peeling process S2) Once the test preparation step S1 is completed, the peeling step S2 is carried out. As shown in Figure 4(a), the peeling bolt 2 is screwed into the nut 11 from above, and its tip is brought into contact with the shaft 5. In this state, as shown in Figure 4(b), when the peeling bolt 2 is further screwed downward relative to the template body 1, the tip of the peeling bolt 2 is restrained from descending by the shaft 5, so instead of the peeling bolt 2 descending, the template body 1 is lifted. Thus, the template body 1 is peeled off from the simulated foundation concrete 20, as shown in Figure 4(c).

[0032] Thereafter, the area of ​​peeled concrete is measured, and the ratio of the peeled area of ​​concrete to the area of ​​the underside 1b of the template body 1 is calculated to evaluate the degree of adhesion between the template body 1 and the simulated foundation concrete 20. The degree of adhesion is evaluated from the results obtained by conducting multiple template peeling tests at regular intervals after the simulated foundation concrete 20 is poured.

[0033] (Second embodiment) As described above, the present invention is not limited to the above-described embodiments. For example, in the template peeling test specimen 200 of Fig. 5, the nut 11, peeling bolt 2, and shaft 5 are the same as those in the first embodiment, but the shaft 5 differs from the first embodiment in that its descent is constrained by a solid portion 203b provided at the lower end of the long nut 203. In this way, the constraint on the descent of the shaft 5 is not limited to the cut bolt 4. Note that reference numeral 241 denotes an anchoring plate that protrudes in an annular shape from the outer periphery of the solid portion 203b.

[0034] (Third embodiment) 6 shares the nut 11, long nut 3, and cut bolt 4 with the template peeling test specimen 100 of the first embodiment, but has a round bar-shaped portion 702a without a male thread at the tip of the peeling bolt 702, which is abutted against the upper end of the cut bolt 4 to restrain the peeling bolt 702 from descending. In this case, the cut bolt 4 corresponds to the descending restraint member. In the second and third embodiments, the same members as those in the first embodiment are denoted by the same reference numerals and the description thereof will be omitted.

[0035] Alternatively, in the test preparation step, long nuts or cut bolts may be set upright on the bottom wall of the formwork in advance, and the template body may then be placed on these. Multiple shafts may also be used, stacked one on top of the other. [Explanation of symbols]

[0036] 100, 200, 300 Template peeling specimen 10 Templates 11 Nut 20. Mock foundation concrete 2,702 Stripping bolts 5 Shaft (downward restraint member) 3,203 Long Nut 3a Female screw hole 5 Threaded Bolt

Claims

1. A template peeling test method in which a plate-shaped template equipped with nuts penetrating in the thickness direction is embedded horizontally and with its top surface exposed in unhardened simulated foundation concrete, and after the simulated foundation concrete has hardened, the template is lifted up to peel off the template from the simulated foundation concrete, thereby confirming the degree of adhesion between the template and the simulated foundation concrete, a test preparation process in which the template is embedded in the simulated foundation concrete and the simulated foundation concrete is hardened; A template peeling test method characterized by including a peeling step in which a peeling bolt is threaded through the nut from above, and the lower end of the peeling bolt is abutted against a downward restraint member installed in the mock foundation concrete so that it cannot be lowered, and the peeling bolt is threaded downward relative to the template to lift the template and peel it off from the mock foundation concrete.

2. The test preparation step includes: a template assembling process in which the stripping bolt is screwed into the female screw hole of the nut from above, and the male screw portion of the stripping bolt is extended from below the nut, and a long nut is screwed partway onto the male screw portion from below, and a cut bolt is screwed into the female screw hole of the long nut from below; A template placing step of placing the template in a formwork for molding simulated foundation concrete; A concrete pouring step of pouring the simulated foundation concrete; a shaft insertion step of inserting a shaft made of a rod-shaped member into the female screw hole of the long nut after removing the stripping bolt; and The template peeling step includes:

2. The template peeling test method according to claim 1, wherein the shaft is used as the downward restraint member, and the lower end of the peeling bolt is brought into contact with the shaft before the peeling bolt is threaded into the long nut.

3. A template peeling test specimen is used to confirm the degree of adhesion between the template and the simulated foundation concrete by embedding a plate-shaped template horizontally with its upper surface exposed in unhardened simulated foundation concrete, and then lifting the template after the simulated foundation concrete has hardened to peel the template from the simulated foundation concrete, a plate-shaped template having a nut penetrating therethrough in the thickness direction; a simulated foundation concrete in which the plate-shaped template is embedded; A stripping bolt that is threaded into the nut from above; a downward restraining member that is provided in the simulated foundation concrete, abuts against a lower end of the peeling bolt, and restrains the downward movement of the peeling bolt when the peeling bolt threads downward relative to the template; A template peel test specimen comprising:

4. a long nut that is screwed from below onto the stripping bolt that is threaded through the nut; A cut bolt screwed partway into the female screw hole of the long nut from below; Equipped with the downward restraint member is a shaft of a rod-shaped member inserted into the female screw hole of the long nut from above and whose downward movement is restrained by the cut bolt, 4. A template peel test specimen according to claim 3, wherein the peel bolt is configured to be threaded from above the nut and to abut against the shaft before being threaded into the long nut.

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