TW396275B - Method and apparatus for testing the adhesive strength of the concrete and steel bar - Google Patents

Abstract

This testing method and apparatus of concrete and steel bar adhesive strength by using the specific boring and lever principle to measure the adhesive strength of the concrete and steel bar on-the-spot. The method mainly comprises the steps of positioning, boring, wedging, applying force, and conversion. The apparatus has a wedged member, an extended portion, a chopped corner portion placed between the wedged member and the extended portion. The structure can make the measurement easier, testing procedure straightforward, simple process, easy conversion, and testing equipment simplified without affecting the main structure. In addition, it is very helpful for the safety test for the buildings after earthquakes.

Description

V. Description of the invention (1) [Technical Field] The present invention relates to a method and device for testing the bond strength between concrete and steel bars, in particular, a clever use of a specific core drilling method and the principle of leverage, which can detect concrete and steel bars on the spot. Method and device for bonding strength. [Previous technology] According to the existing test methods for grip strength of concrete and steel bars, as shown in Figures 8 and 9, a steel bar 9 1 1 must be hardened in a concrete 9 1 2 to form a test sample 9 1 . Then, a tensile testing machine 92 is placed. The tensile testing machine 92 mainly includes an upper clamping portion 9 2 1, a lower clamping portion 9 2 2, and a control panel 9 2 3. During the experiment, the steel bar 9 1 1 of the test sample 9 1 is clamped and fixed by the upper clamping portion 9 2 1, and the concrete 9 1 2 of the test sample 9 1 is clamped and fixed by the lower clamping portion 9 2 2 Then, start to increase the pulling force until it breaks. Finally, the maximum pulling force value can be read from the control panel 9 2 3. Take this. The grip strength of the concrete 9 1 2 and the reinforcing steel 9 1 1 can be detected. Strictly speaking, the grip strength includes the resistive part of the ribs on the surface of the steel bar, plus the adhesive part of the surface of the steel bar. However, its main disadvantages are: 1. It cannot be detected on site. Known methods are limited to laboratory use and cannot be tested on site. Especially after the 1992 earthquake, there are many new buildings, dwellings, institutions, and schools that cannot be detected with the naked eye. Device.

Page 4 V. Description of the invention (2) 2. Testing is expensive. The traditional tensile testing machine is expensive, and the main structure needs to be made or destroyed separately to obtain the test sample 9 1, which is expensive. 3. The detection device is bulky. The traditional tensile testing machine 92 is bulky and not easy to carry, and its application range is narrow. 4. It is not easy to directly measure the degree of adhesion. The maximum bearing force measured in this traditional axial tensile test includes two parts: the resistance part of the ribs on the surface of the steel bar, and the bonding force on the surface of the steel bar. Therefore, it is not easy to directly measure the degree of adhesion. In view of this, the academia and industry of civil construction have been working hard to research and develop new methods and new devices that can overcome the above disadvantages. [Objective and Effect] The main purpose of the present invention is to provide a method and device for testing the strength of concrete-reinforcement bonding, which cleverly utilizes the specific core drilling method and the principle of damaged rods, so that the strength of the rebar can be detected on site. A secondary object of the present invention is to provide a method and device for testing the bond strength between concrete and steel bars, which can achieve the purpose of simple and convenient test methods and lightweight devices. Another object of the present invention is to provide a bond between concrete and steel bars. The method and device of the knot strength test can achieve local damage in only a small area without affecting the main structure. [Technical content] The present invention provides a method for providing a method and a device for testing the bond strength between concrete and steel bars. Among them, the methods mainly include:

V. Description of the invention (3) 1. Positioning step: Select a concrete surface close to a steel bar to be tested i 2. Drilling step: Drill a circular, rectangular or square-shaped concave portion so that the concave portion surrounds The concrete forms a suspended portion, the suspended portion has an adhesive end adhered to the surface of the reinforcing bar and a suspended suspended end, wherein the length between the two ends of the suspended portion is defined as the length of the suspended portion and the axis of the steel bar The line is defined as the first axis line, and the axis line of the suspended portion is defined as the second axis line, and the first axis line is approximately perpendicular to the second axis line. A test device is inserted into the test device. One end of the device is inserted into a predetermined depth of the recess, and the other end is provided with a hook hole. The hook hole is used to hook a force applying device, and the direction of force application is approximately parallel to the first Axis, and the force applying device has a maximum force reading element; 4. force applying step: gradually applying force from the force applying device until the suspended part is bent and broken; 5. conversion step: using the most The maximum force reading to withstand forces resulting element to the principle of leverage to withstand the maximum torque trans Release end of the adhesive. One end of the device is a snap-in portion, the other end is an extension portion, and the middle is a chamfered portion, wherein: the snap-in portion has a predetermined length so as to be able to be inserted into a concave portion of concrete at approximately perpendicular to the axis direction of the steel bar; The extension portion is provided with at least one hook hole; and the chamfered portion has a chamfered angle so that the device stops when it is inserted to a predetermined depth.

V. Description of the invention (4) The above and other objects and advantages of the present invention are not difficult to obtain in-depth understanding from the detailed description and accompanying drawings of selected embodiments below. [Brief Description of the Drawings] The following is a detailed description of the present invention with a preferred embodiment and the drawings: The first drawing is a flowchart of the method of the present invention, the second drawing is a schematic view of an application occasion of the present invention, and the third The figure is a longitudinal sectional view taken along line 11-II of the second figure. The fourth figure is a schematic perspective view of the present invention after the core is drilled. The fifth figure is a transverse section of the fourth figure along line VV. The sixth figure is the device of the invention. The schematic diagram after the installation is the seventh diagram of the device of the present invention. The eighth diagram is the conventional tensile force. The test sample for the experimental machine is the ninth diagram is the simplified diagram of the conventional tensile experiment machine. Step 1 1 Drilling step 1 2 Clamping step 1 3 Force applying step 1 4 Conversion step 1 5 Concrete 2 Recessed part 2 1 Suspended part 2 2 Adhesive end 2 2 1 Suspended end 2 2 2 Rebar 3 Drill core, device 4 Test Device 5 Snap-in section 5 1 Corner section 5 2 Extension section 5 3 Hook hole 5 3 1, 5 3: 2

V. Description of the invention (5)

Maximum force reading element 6 Second axis line Y

Force applying device 6 First axis line X

Applying force F 1 Length of the suspension portion L Moment M Insertion depth 1 ^ The vertical distance L2 from the direction of the application force to the suspension end L2 Thrust at the inner end of the test device [Detailed description of the embodiment] The present invention relates to a kind of bonding between concrete and steel bars The method and device for strength test are used to detect the bonding strength between a concrete 2 and a steel bar 3. Please refer to the first to seventh drawings. The method part includes at least the following steps: 1. Positioning step 11: Select a concrete 2 surface close to a certain steel bar 3 to be inspected. In practice, this step can also use electromagnetic waves or other non-destructive speculative methods to find the position of the steel bar 3, or directly drill a test hole (not shown in the figure) with a drilling device 4 to determine the steel bar 3 in advance. Actual location. 2. Drilling step 1 2: Drill a circular, rectangular (not shown) or T-shaped (not shown) recessed portion 2 1 so that the concrete surrounded by the recessed portion 21 forms a suspended portion. (Or a small-sized concrete column), the suspended portion 2 2 has an adhesive end 2 2 1 adhered to the surface of the reinforcing bar 3 and a suspended end 2 2 2, wherein the suspended portion 2 2 The length between the two ends is defined as the length L of the suspended portion, the axis line of the reinforcing bar 3 is defined as the first axis line X, and the axis line of the suspended portion 22 is defined as the second axis line Y, and the first The axis line X is approximately perpendicular to the second axis line Y.

V. Description of the invention (6) III. Clamping step 13: A test device 5 is clamped in the recessed portion 21, and one end of the device 5 is latched into a predetermined depth of the recessed portion 22 while the other end has One or several hook holes 5 3 1, 5 3 2, the hook holes 5 3 1, 5 3 2 are used to hook a force applying device 6, the direction of the force F is approximately parallel to the first axis X, and the force The force device 6 has a maximum force reading element 6 1. 4. Step 14 of applying force: The force is gradually applied by the force applying device 6 until the suspended portion 22 is broken due to a bending phenomenon caused by an excessive bending moment M. V. Conversion step 15: Based on the maximum bearing force obtained by the maximum force reading element 61, the maximum bearing moment of the adhesive end 2 2 2 is deduced based on the principle of leverage. The parameters required for the aforementioned lever principle are as follows: (a) The length of the overhang is defined as L, (b) The applied force is F, (c) The insertion depth of the test device is defined as Li, (d) The applied force The vertical distance from the direction to the floating end is defined as L2. (e) Thrust f at the inner end of the test device. The moment M = f * (L-LT) to which the sticking end 2 2 1 of the suspending part 2 2 is subjected; and f 氺 = F 氺 L2, so f = F. 氺 can be deduced to substitute the suspending part. The conversion formula of the moment M to the adhesive end of 2 2 is:

V. Explanation of the invention (7) M = F * L2 * (L — L!) / L! Of course, assuming that the M value calculated above is a value affected by the earthquake, it can be compared with another value not affected by the earthquake The measured value of the group of concrete π Μ Λ is compared with the group π, and the percentage of the post-seismic reinforcement strength of the steel bar can be obtained as the comparison group (%), as an objective reference judgment value (identification by the supplier or building) Staff reference).

Regarding the device part of the bond strength test of concrete and steel bar according to the present invention, it is shown in more detail in Figures 6 and 7. The device 5 has a snap-in portion 5 1 at one end, an extension portion 5 3 at the other end, and a chamfered portion 5 2 at the middle, wherein: the snap-in portion 5 1 has a predetermined length L so as to be approximately perpendicular to the reinforcement 3. One of the recesses 2 2 of the concrete 2 is inserted in the axial direction X. The extending portion 5 3 is provided with at least one hook hole 5 3 1, 5 3 2. And the chamfered portion 52 has a chamfered angle (preferably between 30 and 90 degrees), so that the device 5 stops when it is inserted to a predetermined depth.

Of course, the distance between the hook holes 5 3 1 and 5 3 2 and the chamfered portion 5 2 is approximately an integer multiple of a predetermined length of the snap-in portion 51 to facilitate calculation. For example, the length of the snap-in portion 51 is one centimeter, and the distances between the hooking gifts 5 3 1 and 5 3 2 and the corner portion 52 are three and five centimeters, respectively, to facilitate calculation. With this, the efficacy and advantages of the present invention can be summarized as follows: 1. It can be tested in the field. It has a wide range of applications, whether it is under construction or completed.

Page ίο 5. Description of the invention (8) 2. The detection steps are simple. The process is simple and easy to convert, and the degree of knotting is directly measured. 3. Streamlined testing equipment. Small size and easy to carry. 4. Does not affect the main structure. Since the protective layer is only damaged in small parts, it does not affect the main structure of the building. The above is only a detailed description of the present invention through a preferred embodiment, and any simple modifications and changes made to the embodiment will not depart from the spirit and scope of the present invention. From the above detailed description, those skilled in the art can understand that the present invention can indeed achieve the aforesaid objectives, and that it has indeed complied with the provisions of the Patent Law, and filed an application for an invention patent.

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Claims (1)

> τ VI. Scope of patent application1. A method for testing the bond strength between concrete and steel bars. 1 .. Use: .. to check the bond strength between a concrete bar and a steel bar, including at least the following steps: Step: Select a concrete surface that is close to a certain inspection, i ... IjH; Drilling steps: drill into a ring, rectangular, shape. The recess is surrounded by the recessed part, the adhesive end and middle of the suspended part, and the suspended minister Degree,… center, line, 5 is the second axis, second axis is the third axis. Steps of snap-in: In the —G3 .. Into the department. — Apply for the card. The end has a hook and a ._applied, force-fitting, so that the surface of the suspended portion tends to be the meaning of the hanging line / defines the first line and about one end and the other five ~, the conversion step is used to hang about flat with By the application of the suspended part, the measure is given by the large bearing. The shaft of a maximum force application device gradually generates a crack and the most force is said to buy. The force is selected by the lever _ or the well. The shape of the recessed part. The concrete is formed to have a length and a degree between the end and the end of the suspended part adhering to the steel and the suspended part. The stern line determines the second line of the suspending section. _ _,-And _. The first axis. The center line is perpendicular to the first. A test. One of the device sections of the test device-predetermined depth, rolling, the hook hole system. Position, the direction line of its force _, and the force applying device ............ take ¾ pieces; apply the force until the damage; take the piece-where. Get. F Principle of anti ... im belongs to M Page 13 > τ VI. Scope of patent application1. A method for testing the bond strength between concrete and steel bars. 1 .. Use: .. to check the bond strength between a concrete bar and a steel bar, including at least the following steps: Step: Select a concrete surface that is close to a certain inspection, i ... IjH; Drilling steps: drill into a ring, rectangular, shape. The recess is surrounded by the recessed part, the adhesive end and middle of the suspended part, and the suspended minister Degree,… center, line, 5 is the second axis, second axis is the third axis. Steps of snap-in: In the —G3 .. Into the department. — Apply for the card. The end has a hook and a ._applied, force-fitting, so that the surface of the suspended portion tends to be the meaning of the hanging line / defines the first line and about one end and the other five ~, the conversion step is used to hang about flat with By the application of the suspended part, the measure is given by the large bearing. The shaft of a maximum force application device gradually generates a crack and the most force is said to buy. The force is selected by the lever _ or the well. The shape of the recessed part. The concrete is formed to have a length and a degree between the end and the end of the suspended part adhering to the steel and the suspended part. The stern line determines the second line of the suspending section. _ _,-And _. The first axis. The center line is perpendicular to the first. A test. One of the device sections of the test device-predetermined depth, rolling, the hook hole system. Position, the direction line of its force _, and the force applying device ............ take ¾ pieces; apply the force until the damage; take the piece-where. Get. F Principle of anti ... im belongs to M Page 13 6. Scope of patent application What is the maximum bearing torque? 2 • The method of coagulation _4 _ Austrian junction strength test as described in the scope of patent application, item 1.1.1, wherein the length of the suspended cyanide is defined as L and the force is F 'The insertion of the test device The depth is defined as: The vertical distance from the direction of the multi-force to the floating end is set to 1, 2_., And the moment M to which the m end is subjected-the formula is: M = F * L.2 * (L — L!) / L !. 3 · A kind of mixed soil and steel bar „.__ Strong_degree test .. The installation-ink ..., --- ----check ~ measured in 'a concrete and a reinforced concrete-of-bonding- -Strong-degree-,-The one end of the device is-the snap-in part, and the other. 7 ... the end one is an extension-extend-part one,-^ one middle--between :: is an option__ 舍-部, where —: The △ part of the card is also provided with two predetermined lengths so as to be able to insert a recessed part of concrete in the axis-friendly direction of the tendon; the extension is provided with at least one hanging-fishing hole; and The chamfered part has a fold-angle, so that the device will stop when the device-set_insert_me urgent_yuding depth-degree. 4 · The bond strength between concrete and steel as described in item 3 of the scope of patent application, The test device, wherein the distance from the hooking hole to the j / t corner is approximately an integer multiple of the predetermined length of the snap-in portion. Page 14