A masonry in-situ shear strength tester using shear transfer method

Abstract

A masonry in-situ shear strength tester using a shear rotation method comprises a shear rotation clamp for clamping an in-situ rectangular sample in the masonry; the shear rotation clamp is connected to a reaction device and a force applying device through a connecting device; the bottom surface of the reaction device is mounted on the side wall of a rectangular hole in the masonry and a metal joint is enclosed therein; the force applying device is installed inside the reaction device and the metal joint is sleeved therein. The present invention clamps the in-situ rectangular sample in the masonry using a shear rotation clamp, and then applies a shear rotation force to the in-situ rectangular sample through a connecting device, a force applying device and a reaction device until the in-situ rectangular sample is sheared and destroyed, reads the maximum shear rotation force value of the in-situ rectangular sample, and calculates the shear strength of the masonry according to a theoretical formula, which is highly practical and accurate in testing.

Description

Technical Field

[0001] The invention relates to a masonry in-situ shear strength detection instrument using a shear transfer method. Background Art

[0002] The masonry of the retaining wall directly bears the lateral horizontal load, and the masonry in the earthquake-resistant area is subjected to the horizontal earthquake load, both of which require the masonry to have corresponding shear strength. Therefore, it is very important to test the in-situ shear strength of the masonry.

[0003] In the prior art, there are two main methods for testing the in-situ shear strength of masonry: (1) The in-situ single shear method is to perform a shear test along a single horizontal mortar joint on the masonry to test the shear strength of the masonry. The disadvantage of this method is that for different masonry, it is necessary to produce bulky reinforced concrete force transmission parts of different sizes, which is labor-intensive and inefficient, affecting the practicality of the test. (2) The in-situ double shear method is to use an in-situ shear instrument to perform a double-sided shear test on a single or double straight brick on the masonry to test the shear strength of the masonry. The disadvantage of this method is that the instrument axis is required to coincide with the brick axis during the test, but in actual testing, due to factors such as the masonry level and brick size, the double-sided straight bricks are often not on the same axis, resulting in the inability of the instrument axis to coincide with the brick axis, affecting the accuracy of the test.

[0004] Since the prior art has the above-mentioned deficiencies, design improvements are needed. Summary of the invention

[0005] The present invention proposes a masonry in-situ shear strength transfer shear method detector with strong practicability, accurate detection and reasonable design. The detector can solve the problems of practicability and accuracy existing in various existing masonry in-situ shear strength detection methods.

[0006] The technical solution adopted by the present invention is: a masonry in-situ shear strength tester using a shear rotation method, comprising a shear rotation clamp for clamping an in-situ rectangular sample in the masonry; the shear rotation clamp is connected to a reaction device and a force applying device through a connecting device; the bottom surface of the reaction device is mounted on the side wall of a rectangular hole in the masonry and a metal joint is enclosed therein; the force applying device is installed inside the reaction device and the metal joint is sleeved therein. The present invention clamps the in-situ rectangular sample in the masonry through a shear rotation clamp, and then applies a shear force to the in-situ rectangular sample through a connecting device, a force applying device and a reaction device until the in-situ rectangular sample is sheared and destroyed, reads the maximum shear force value of the in-situ rectangular sample, and calculates the shear strength of the masonry according to a theoretical formula.

[0007] Furthermore, the bottom surface of the in-situ rectangular specimen is connected to the masonry through a shear-bearing horizontal mortar joint.

[0008] Furthermore, the shearing fixture comprises two metal clamps symmetrically arranged on the sides of the in-situ rectangular specimen; the metal clamp is a rectangular flat plate, and 4 to 6 circular holes for positioning and fixing bolts are evenly and symmetrically drilled on the vertical sides of the side, and the two metal clamps are connected and fixed by positioning and fixing bolts; the upper surface of the metal clamp is evenly tapped with multiple connecting screw holes for connecting to the connecting device; the lower surface of the metal clamp is flush with the upper surface of the sheared horizontal mortar joint.

[0009] Furthermore, the connecting device includes a metal connecting plate and a metal joint; the metal connecting plate is a rectangular flat plate with multiple connecting bolt circular holes drilled therein matching the connecting screw holes; the metal connecting plate is connected and fixed to the connecting screw holes on the metal clamping plate through connecting bolts; the metal joint is a regular hexagon and is vertically installed at the center of the metal connecting plate; the metal joint is connected to a reaction force device and a force application device.

[0010] Furthermore, the reaction device comprises a metal 7-shaped body; the bottom surface of the metal 7-shaped body is mounted on the side wall of the rectangular hole in the masonry and the metal joint is enclosed therein.

[0011] Furthermore, the force-applying device is installed inside the metal 7-shaped main body and the metal joint is sleeved therein, which is a torsional structure that allows the shearing fixture and the connecting device to rotate relative to the in-situ rectangular specimen. The torsional structure can adopt a variety of structures such as a hydraulic torque wrench, as long as it can allow the shearing fixture and the connecting device to rotate relative to the in-situ rectangular specimen.

[0012] Furthermore, the force-applying device is provided with a display screen for displaying the shear force value of the masonry, and the force-applying device is provided with a control element for detecting the shear force value applied by the force-applying device to the in-situ rectangular specimen.

[0013] The beneficial effects of the present invention are as follows: (1) During the testing process, the detector is used to apply the rotational shear force to the in-situ rectangular sample, the maximum rotational shear force value is measured, and the masonry shear strength is calculated according to the theoretical formula, which is practical and accurate. (2) Compared with the existing in-situ single shear method for masonry in-situ shear strength, since there is no need to make bulky reinforced concrete force transmission parts of different sizes, the labor intensity is reduced, the testing efficiency is improved, and the practicality is enhanced; compared with the existing in-situ double shear method for masonry in-situ shear strength, since there is no need to consider whether the instrument axis coincides with the brick axis, by adjusting the position, the shear surface can be easily located on the upper surface of the shear horizontal mortar joint, thereby enhancing the accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic front view of the structure of the present invention.

[0015] Figure 2 It is a schematic side view of the structure of the present invention.

[0016] Figure 3 It is a schematic top view of the structure of the present invention.

[0017] Figure 4 It is a front view showing the use of the present invention.

[0018] Figure 5 It is a side view schematically showing the use of the present invention.

[0019] Figure 6 It is a schematic top view of the use of the present invention. DETAILED DESCRIPTION

[0020] The present invention is further described below in conjunction with specific embodiments, but the present invention is not limited to these specific embodiments. Those skilled in the art should recognize that the present invention covers all possible alternatives, improvements and equivalents within the scope of the claims.

[0021] Reference Figure 1-6 A masonry in-situ shear strength tester using a shear rotation method comprises a shear rotation clamp 11 for clamping an in-situ rectangular sample 15 in a masonry 17; the shear rotation clamp 11 is connected to a reaction device 1 and a force applying device 4 via a connecting device 3; the bottom surface of the reaction device 1 is mounted on the side wall of a rectangular hole 18 in the masonry 17 and a metal joint 2 is enclosed therein; the force applying device 4 is installed inside the reaction device 1 and the metal joint 2 is sleeved therein. The present invention clamps an in-situ rectangular sample 15 in a masonry 17 using a shear rotation clamp 11, and then applies a shear rotation force to the in-situ rectangular sample 15 via the connecting device 3, the reaction device 1 and the force applying device 4 until the in-situ rectangular sample 15 is sheared and destroyed, reads the maximum shear rotation force value of the in-situ rectangular sample 15, and calculates the masonry shear strength according to a theoretical formula.

[0022] The bottom surface of the in-situ rectangular sample 15 of this embodiment is connected to the masonry 17 through the shear horizontal mortar joint 16. The height of the in-situ rectangular sample 15 is (the thickness of 2 layers of standard concrete ordinary bricks + the thickness of 1 horizontal mortar joint), and the length is (the length of 2 standard concrete ordinary bricks + the width of 1 vertical mortar joint).

[0023] The shearing fixture 11 described in this embodiment includes two metal clamps 10 symmetrically arranged on the sides of the in-situ rectangular specimen 15; the metal clamp 10 is a rectangular flat plate with a length of 550㎜, a height of 130㎜ and a thickness of 22㎜; four circular holes 12 for positioning and fixing bolts with a hole diameter of 16.5㎜ are evenly and symmetrically drilled on the vertical sides of the side of the metal clamp 10; the two metal clamps 10 are connected and fixed by positioning and fixing bolts 9 of specification M16; the upper surface of the metal clamp 10 is evenly tapped with three connecting screw holes 8 of specification M16 for connecting with the connecting device 3; the lower surface of the metal clamp 10 is flush with the upper surface of the shear horizontal mortar joint 16.

[0024] The connecting device 3 described in this embodiment includes a metal connecting plate 6 and a metal joint 2; the metal connecting plate 6 is a rectangular flat plate with a length of 550 mm, a width of 290 mm, a thickness of 14 mm, and is drilled with 6 connecting bolt circular holes 5 with a hole diameter of 16.5 mm to match the connecting screw holes 8; the metal connecting plate 6 is connected and fixed to the connecting screw holes 8 on the metal clamping plate 10 by connecting bolts 5; the metal joint 2 is a regular hexagon with a side distance of 46 mm, and is vertically installed at the center of the metal connecting plate 6; the metal joint 2 is connected to a reaction device 1 and a force application device 4.

[0025] The reaction device 1 of this embodiment includes a metal 7-shaped body; the bottom surface of the metal 7-shaped body is mounted on the side wall of the rectangular hole 18 in the masonry 17 and surrounds the metal joint 2 therein.

[0026] The force-applying device 4 of this embodiment is installed inside the metal 7-shaped body and the metal joint 2 is sleeved therein, which is a torsion structure that allows the shearing fixture 11 and the connecting device 3 to rotate relative to the original rectangular specimen 15. The torsion structure adopts a hydraulic torque wrench structure.

[0027] The force applying device 4 of this embodiment is provided with a display screen 14 for displaying the shear force value of the masonry, and the force applying device 4 is provided with a control element 13 for detecting the shear force value applied by the force applying device 4 to the in-situ rectangular specimen 15 .

[0028] The use process of this embodiment is as follows: (1) Marking: Mark the edge of the in-situ rectangular sample 15 and the rectangular hole 18 at the appropriate position of the masonry 17. (2) Installation: Install the masonry track cutting machine according to the marked edge and the thickness of the masonry 17. (3) Sample preparation: Start the masonry track cutting machine to cut, remove the excess masonry in the rectangular hole 18, and remove at least 50mm of masonry between the in-situ rectangular sample 15 and the side wall of the rectangular hole 18. The side of the in-situ rectangular sample 15 is polished and smoothed with a polishing machine. (4) Positioning and fixing: The metal clamps 10 are symmetrically placed on both sides of the in-situ rectangular specimen 15, the lower surface of the metal clamps 10 is flush with the upper surface of the shear horizontal mortar joint 16, and the positioning and fixing bolts 9 are connected and fixed; the metal connecting plate 6 is placed on the upper surface of the metal clamps 10, and is connected and fixed to the connecting screw holes 8 on the metal clamps 10 through the connecting bolts 5; the force-applying device 4 sets the metal joint 2 therein, and the bottom surface of the reaction device 1 is mounted on the side wall of the rectangular hole 18. (5) Measurement: The shear force is applied to the in-situ rectangular specimen 15 by using the force-applying device 4, the reaction device 1, the connection device 3, and the shear fixture 11 until the in-situ rectangular specimen 15 is sheared and destroyed, the maximum shear force value of the in-situ rectangular specimen 15 is read, and the shear strength of the masonry is calculated according to the theoretical formula.

Claims

1. A masonry in-situ shear strength tester using a shear transfer method, characterized in that: It comprises a shear rotation clamp for clamping an in-situ rectangular specimen in a masonry; the bottom surface of the in-situ rectangular specimen is connected to the masonry through a shear-bearing horizontal mortar joint; the shear rotation clamp is connected to a reaction device and a force-applying device through a connecting device; the connecting device comprises a metal connecting plate and a metal joint; the reaction device comprises a metal 7-shaped main body, the bottom surface of which is mounted on the side wall of a rectangular hole in the masonry and the metal joint is surrounded therein; the force-applying device is installed inside the metal 7-shaped main body and the metal joint is sleeved therein, and is a torsional structure for rotating the shear rotation clamp and the connecting device relative to the in-situ rectangular specimen.

2. The masonry in-situ shear strength tester according to claim 1, characterized in that: The shearing fixture comprises two metal clamps symmetrically arranged on the sides of the in-situ rectangular specimen; the metal clamps are rectangular flat plates, and 4 to 6 circular holes for positioning and fixing bolts are evenly and symmetrically drilled on the vertical sides of the sides, and the two metal clamps are connected and fixed by positioning and fixing bolts; the upper surface of the metal clamp is evenly tapped with multiple connecting screw holes for connecting to the connecting device; the lower surface of the metal clamp is flush with the upper surface of the sheared horizontal mortar joint.

3. The masonry in-situ shear strength tester according to claim 1, characterized in that: The metal connecting plate is a rectangular flat plate with multiple circular connecting bolt holes drilled therein to match the connecting screw holes; the metal connecting plate is connected and fixed to the connecting screw holes on the metal clamping plate through connecting bolts; the metal joint is a regular hexagon and is vertically installed at the center of the metal connecting plate; a reaction force device and a force application device are connected to the metal joint.

4. The masonry in-situ shear strength transfer shear method detector according to claim 1, characterized in that: The force applying device is provided with a display screen for displaying the shear force value of the masonry, and the force applying device is provided with a control element for detecting the shear force value applied by the force applying device to the in-situ rectangular specimen.

Images