Template peeling test method and template peeling test specimen

Abstract

During the template peeling test, ensure that the simulated foundation concrete does not lift up along with the template and that the precast template does not crack. [Solution] The template peeling test method of the present invention includes a test preparation process in which the mock foundation concrete is hardened with a template 10 embedded in the mock foundation concrete 20, and a peeling process in which a peeling bolt is screwed from above into a nut 11 that penetrates the template 10 in the thickness direction, and the lower end of the peeling bolt 2 is abutted against a downward restraint member 5 that is provided in the mock foundation concrete 20 so that it cannot be lowered, and the peeling bolt 2 is screwed downward relative to the template 10, thereby lifting the template 10 and peeling it off from the mock foundation concrete 20.

Description

[Technical field]

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

[0002] Templates with through holes for positioning the anchor bolts or main reinforcement bars in steel or concrete plate members are widely used to position the attachment bolts for seismic isolation members in seismic isolated buildings, anchor bolts for steel columns in general buildings, and column reinforcement bars (rebars) in reinforced concrete buildings. Such templates must be sufficiently tightly attached to the lower foundation so that they do not come off from the lower foundation when an earthquake occurs, 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 and lifted by a crane (not shown) to peel it off from the simulated concrete foundation 20. Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the above-mentioned conventional peel-off test, if the mock foundation concrete is not fixed to the floor surface, there is a problem that the mock foundation concrete will lift up together with the template, and if the template is made of precast concrete, when it is hung at four points, the direction of the wires is not parallel to the thickness direction of the template, so bending stress acts on 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 peel-off test method and a template peel-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 are 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-mentioned problems 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 it off the mock foundation concrete, thereby checking the degree of adhesion between the template and the mock foundation concrete. The template peeling test method according to the present invention is characterized by comprising a test preparation step of hardening the simulated foundation concrete with the template embedded in the simulated foundation concrete, and a peeling step of screwing a peeling bolt into the nut from above and abutting the lower end of the peeling bolt against a downward restraint member provided in the simulated foundation concrete so as not to be able to descend, thereby screwing the peeling bolt downward relative to the template to lift the template and peel it off from the simulated foundation concrete.

[0006] In the template peeling test method of the present invention, the lower end of the peeling bolt screwed into the nut of the template from above is restrained by abutting against the descent restraint means provided so that it cannot be lowered, and then the peeling bolt is screwed in. The peeling bolt screws into the template and protrudes from the bottom, but since the lower end of the peeling bolt abuts against the descent restraint means and does not descend, the template is raised relative to the simulated foundation concrete by the amount that the peeling bolt protrudes. In this way, the template is peeled off from the simulated foundation concrete.

[0007] At this time, the peeling 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 together with the template. Also, because the peeling 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 makes it possible to prevent the template from cracking, even if it 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 the underside of the nut so as to screw a long nut partway into 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 insertion 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 long nut in the template assembly process, they can be installed simultaneously and integrally in the formwork for the simulated foundation concrete in the template placement process. Then, when a rod-shaped shaft is inserted into the long nut in the shaft insertion process, the lower end of the shaft abuts against the cut bolt, so that the descent of the shaft is restrained. In the template peeling process, the lower end of the stripping bolt is abutted against the shaft before the stripping bolt is screwed into the long nut, using the shaft as a descent restraint member, so that the stripping bolt is not connected to the long nut. Therefore, when the screwing bolt is screwed to protrude downward from the template, the template can be lifted up 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 in the thickness direction, simulated foundation concrete in which the plate-shaped template is embedded, a stripping bolt screwed into 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 when the stripping bolt is screwed downward.

[0010] The template peeling test specimen of the present invention comprises a long nut that is screwed from below onto a peeling bolt that is screwed through the nut, and a cut-to-length bolt that is screwed partway into the female threaded hole of the long nut from below, and the descent restraint member consists 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-to-length bolt, and it is preferable that the peeling bolt that is screwed from the above of the nut abuts against the shaft before being screwed into the long nut. Effect of the Invention

[0011] As described above, the template peeling test method and template peeling test specimen of the present invention can prevent the simulated foundation concrete from lifting up together with the template. Furthermore, even if the template is made of precast material, it can be prevented from cracking due to lifting. [Brief description of the drawings]

[0012] [Figure 1] FIG. 1 is a plan view showing a template peeling test piece according to a first embodiment of the present invention. [Diagram 2] 2 is a cross-sectional view taken along line XX in FIG. [Diagram 3] FIG. 2 is an explanatory diagram showing how to prepare for a template peeling test after forming the template peeling test specimen of FIG. 1. [Figure 4] FIG. 4 is an explanatory diagram showing how a template peeling test is carried out after the preparations shown in FIG. 3 are completed. [Diagram 5] FIG. 11 is a cross-sectional side view showing a template peeling test piece according to a second embodiment of the present invention. [Figure 6] FIG. 11 is a cross-sectional side view showing a template peeling 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 PREFERRED EMBODIMENTS

[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 can be modified as appropriate without departing from the gist of the present invention.

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

[0015] (Template peeling test specimen) As shown in Figures 1 and 2, the template peeling test specimen 100 comprises a template 10, a simulated 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 simulated foundation concrete 20, a long nut 3 embedded in the simulated foundation concrete 20 to support the template 10 from below, a cut bolt 4, and a rod-shaped shaft (descent restraint member) 5 housed in 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 Fig. 1, has a somewhat large circular hole 12 provided in the center, numerous small holes 13,... arranged in two circles at equal angular intervals on the inside and outside of the diameter of the template body 1, and bottom end reinforcements 14,... buried 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 mock foundation concrete 20, and the small holes 13,... are used to let air escape from under the template body 1 when the concrete is poured.

[0018] 3, the nut 11 has a female screw 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, respectively, and a leg portion 11c extending downward from the lower surface 1b of the template body 1. The leg portion 11c is embedded in the simulated foundation concrete 20.

[0019] The peel bolt 2 is a hexagonal bolt, and as shown in FIG. 3(a), before the peel test is performed, the bolt is screwed 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 its inner surface having 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 protruding below the nut 11 until its upper end abuts against the lower end of the nut 11.

[0021] 3(a), the cut bolt 4 is connected to the long nut 3 by screwing its upper end into the female screw hole 3a from below the long nut 3. A circular annular anchor plate 41 is screwed and welded near the lower end of the cut bolt 4 to prevent the long 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 Fig. 4(a), its lower end is abutted against the upper end of the cut bolt 4 so that it cannot be lowered. The shaft 5 is long enough that its upper end extends into the nut 11 when it is housed in the long nut 3.

[0023] (Template peeling test method) Next, a template peeling test method according to the present embodiment will be described. The template peeling test method according to the present 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 peeling test of this embodiment, the template body 1 may be made of a steel plate, concrete, or mortar, but is particularly suitable for use with templates made of concrete or mortar, which are easily cracked by bending stress. The template peeling test of the present invention is also applicable to template body 1 that may be circular as shown in FIG. 1, or may be square, annular, or rectangular.

[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 formwork 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 screwed into the female screw hole 11a of the nut 11 from above until the head 2a abuts against the upper surface of the nut 11, and the tip of the male screw portion 2b of the stripping bolt 2 protrudes from the lower side of the nut 11. Next, the long nut 3 is screwed onto the tip of the male screw portion 2b of the stripping bolt 2 until the upper end abuts against the lower end of the nut 11. At this time, the male screw portion 2b of the stripping bolt 2 is screwed into the female screw hole 3a of the long nut 3 from above to halfway. Next, the cut bolt 4 to which the fixing plate 41 has been welded in advance is screwed into the female screw hole 3a of the long nut 3 from below.

[0027] (Formwork assembly process S12) The formwork assembly process S12 is a process for 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 of which is made of a concrete panel reinforced with a square timber, and a bottom wall 82. Since the formwork 8 has the bottom wall 82, the simulated foundation concrete 20 is formed independently from the slab surface at the site. The reinforcement 21 is made by arranging a large number of U-shaped main reinforcements 21a, vertically and horizontally in a lattice shape, and the periphery is reinforced with a plurality of peripheral reinforcements 21b, vertically and horizontally. The reinforcement 21 is only placed on the bottom wall 82 of the formwork 8 and is not fixed to the bottom wall 82.

[0028] (Template mounting 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 reinforcing 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) have level adjustment nuts 42 welded to them, which 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 simulated foundation concrete 20 into the formwork 8. The simulated foundation concrete 20 is cast so that the upper surface 1a of the template body 1 and the upper surface 1a of the simulated foundation concrete 20 are flush with each other.

[0030] (Shaft insertion process S15) When 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 process S1.

[0031] (Peeling process S2) When the test preparation step S1 is completed, the peeling step S2 is performed. As shown in Fig. 4(a), the peeling bolt 2 is screwed into the nut 11 from above, and the tip of the bolt is struck against the shaft 5. In this state, as shown in Fig. 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 the peeling bolt 2 does not descend, but the template body 1 lifts up. Thus, the template body 1 is peeled off from the simulated foundation concrete 20, as shown in Fig. 4(c).

[0032] Thereafter, the area of ​​peeled concrete is measured, and the ratio of the area of ​​peeled concrete to the area of ​​the lower surface 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 a template peeling test multiple times at regular intervals after pouring the simulated foundation concrete 20.

[0033] Second embodiment As described above, the present invention is not limited to the above-mentioned embodiment. For example, in the template peeling test specimen 200 in Fig. 5, the nut 11, peeling bolt 2, and shaft 5 are common to the first embodiment, but the shaft 5 is different from the first embodiment in that the descent of the shaft 5 is restrained by the solid portion 203b provided at the lower end of the long nut 203. In this way, the restraint of the descent of the shaft 5 is not limited to the cut bolt 4. The reference numeral 241 denotes a fixing plate that protrudes in an annular shape from the outer periphery of the solid portion 203b.

[0034] Third embodiment 6 has the same nuts 11, long nuts 3, and cut bolts 4 as 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, members common to the first embodiment are denoted by the same reference numerals and description thereof will be omitted.

[0035] In addition, in the test preparation process, long nuts or cut bolts may be set upright on the bottom wall of the formwork in advance, and the template body may be placed on these. A plurality of shafts may be used by stacking them one on top of the other. [Explanation of symbols]

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

Claims

1. A template peeling test method for confirming the degree of adhesion between the template and the simulated foundation concrete, comprising: embedding a plate-shaped template having a nut penetrating in the thickness direction horizontally and with its upper surface exposed in unhardened simulated foundation concrete; and lifting the template after the simulated foundation concrete has hardened to peel the template off 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 comprising: a peeling bolt is screwed into the nut from above, and the lower end of the peeling bolt is abutted against a downward restraint member installed in the simulated foundation concrete so that it cannot be lowered, and the peeling bolt is screwed downward relative to the template to lift the template and peel it off from the simulated foundation concrete.

2. The test preparation step includes: a template assembly process in which the stripping bolt is screwed into the female screw hole of the nut from above, the male screw portion is extended from the underside of the nut, 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 process for placing the template in a formwork for molding simulated foundation concrete; A concrete pouring process for 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; having 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 screwed 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 and 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 off the simulated foundation concrete, A plate-shaped template having a nut penetrating therethrough in a thickness direction; A simulated foundation concrete in which the plate-shaped template is embedded; A stripping bolt that is screwed into the nut from above; a descent restraining member that is provided in the simulated foundation concrete, abuts against a lower end of the peeling bolt, and restrains the descent of the peeling bolt when the peeling bolt is screwed downward relative to the template; A template peel test specimen comprising:

4. A long nut that is screwed from below onto the peeling bolt that is screwed into 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 that is inserted into the female screw hole of the long nut from above and whose downward movement is restrained by the cut-to-length bolt, 4. The template peel test specimen according to claim 3, wherein the peel bolt, which is screwed into the nut from above, is configured to abut against the shaft before being screwed into the long nut.

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