CN204287011U - Shear strength of masonry testing apparatus - Google Patents

Abstract

A kind of shear strength of masonry testing apparatus, it comprises pull bar, described pull bar comprises head and afterbody, web member is provided with at the head of pull bar, the diameter of web member is greater than the diameter of afterbody, web member end is provided with groove, and slot opening, on the sidewall of web member, is provided with bell mouth shape hole in web member end and is communicated with the groove of web member; The afterbody of pull bar is provided with external thread and coordinates with the first nut, and pull bar is also set with positioning disk and cushion block; Connecting link one end is provided with the ball bumps suitable with the hollow groove on web member, and the other end is provided with the external thread with the second nut screw connection, and connecting link is set with the counter-force supporting seat of hollow structure and the lifting jack of hollow structure; Dynamometer is connected with the sensor electrical be arranged on lifting jack.

Description

Masonry Shear Strength Test Equipment

technical field

The utility model relates to a device for testing the shearing strength of a masonry when the mortar joint of the masonry is destroyed along the masonry structure.

Background technique

Masonry structure is a common structural form in my country, including brick masonry, block masonry, and stone masonry. These masonry structures are made of clay bricks, blocks, stones, etc. Good sex and other characteristics, widely used in our country. A characteristic of the masonry structure is that its compressive strength is much greater than its tensile and shear strength, the bond between the mortar and the block is weak, and it can resist the normal tensile force (vertical upward) and tangential force of the masonry joint. Poor ability to force (horizontally). Due to the gravity of the masonry structure itself, there is generally no normal tension in the masonry joints; however, my country is an earthquake-prone area, and under the action of earthquake loads, the tangential force of the masonry joints is often large. The ability of masonry to resist the tangential force through the joints is determined by the area of the joints and the tangential bond strength of the masonry joints. Therefore, the tangential bond strength of the masonry joints has become an important factor in measuring the seismic capacity of masonry structures. index.

In the national standard "Standards for Test Methods of Basic Mechanical Properties of Masonry" GB/T 50129-2011, there is a test method for the tangential bond strength (shear strength) of masonry along the joint section. The masonry standard shear test block of the same material as the actual project is obtained by testing. However, due to the differences in construction quality, maintenance conditions, and human factors between the masonry standard shear test block and the actual masonry project, Therefore, the data measured in the standard cannot accurately reflect the actual situation of masonry projects. In this test, loads are applied to two open joints at the same time, and the failure load of the first broken open joint is taken as the research object, so there is certain uncertainty in the test.

Contents of the invention

In order to make up for the lack of testing equipment and methods for the shear strength of masonry along the mortar joints, and ensure the seismic bearing capacity of masonry structures meets the safety requirements.

The technical measures taken by the utility model are: a masonry shear strength testing equipment, which includes a tie rod, the tie rod includes a head and a tail, and a connecting piece is arranged at the head of the tie rod, and the diameter of the connecting piece is larger than that of the tail. Diameter, the end of the connecting piece is provided with a groove, the groove is opened on the side wall of the connecting piece, and the end of the connecting piece is provided with a bell-shaped hole communicating with the groove of the connecting piece; the tail of the tie rod is provided with an external thread and the second A nut is matched, and a positioning plate with a central through hole and a spacer are set on the pull rod; one end of the connecting rod is provided with a spherical protrusion that matches the hollow groove on the connecting piece, and the other end is provided with a second nut. The matching external thread is fitted with a hollow structure reaction force support seat and a hollow structure jack on the connecting rod; the force measuring instrument is electrically connected with the sensor arranged on the jack.

The specific features of this program also have that the outer diameter of the locating disc is compatible with the inner diameter of the reaction support seat, and the outer edge of the positioning disc is slidingly matched with the inner wall of the reaction support seat, and moves back and forth along the axis of the pull rod. After the small brick to be tested is clamped and positioned, the center of the positioning plate is located in the middle of the end face of the small brick.

The cushion block is a cuboid, the thickness h is 30mm-50mm, and the dimensions of width B and length L are compatible with the size of the end face of the small brick.

The beneficial effect of this scheme is that it is not necessary to first destroy part of other masonry as described in the "Technical Standards for On-Site Inspection of Masonry Engineering" GB50315-2011 before detection, and it is not necessary to test the shear strength and masonry strength of masonry by core drilling method. As in the "Technical Specifications for Mortar Strength", it is necessary to drill core samples and process them first. The present invention only needs to drill holes on the tested masonry bricks to cause shear failure of the bricks and the surrounding masonry, and measure the maximum shear force. , so as to calculate the masonry shear strength, the test method is simple and quick. The principle of this scheme is simple, the damage to masonry is small, the test data is stable, the method is reliable, and it is suitable for testing the tangential bond strength of masonry joints. Suitable for brick masonry, block masonry, stone masonry and other types of masonry with different thicknesses.

Description of drawings

Fig. 1 is a structural representation of the utility model;

Fig. 2 is a structural schematic diagram of the connector on the pull rod;

Figure 3 is a schematic diagram of the block structure.

In the figure: 1-tie rod; 2-first nut; 3-pad; 4-positioning plate; 5-reaction support seat; 6-jack; 7-dynamometer; 8-second nut; 9-connecting rod ; 10-connector; 11-butacle; 12-through hole; 13-mortar joint to be tested; 14-masonry.

Detailed ways

As shown in Figure 1, a kind of masonry shear strength test equipment, it comprises pull rod 1, and described pull rod 1 comprises head and tail, is provided with connector 10 at the head of pull rod 1, and the diameter of connector 10 is larger than tail The diameter of the connecting piece 10 is provided with a groove, the groove is opened on the side wall of the connecting piece 10, and the end of the connecting piece 10 is provided with a bell-shaped hole extending axially along the pull rod 1 and a concave hole of the connecting piece 10. The groove is connected; the tail of the pull rod 1 is provided with an external thread to cooperate with the first nut 2, and the pull rod 1 is also set with a positioning plate 4 and a spacer 3 . As shown in Figure 2, one end of the connecting rod 9 is provided with a spherical protrusion that matches the hollow groove on the connecting piece 10, and the other end is provided with an external thread that cooperates with the second nut 2, and the connecting rod 9 is sleeved with a hollow The reaction force supporting seat 5 of the structure and the jack 6 of the hollow structure; the force measuring instrument 7 is electrically connected with the sensor arranged on the jack 6 .

The connecting piece 10 and the first nut 2 cooperate to fix the positioning plate 4 and the pad 3; the connecting piece 10 is provided with a groove that can be inserted into the spherical protrusion at the end of the connecting rod 9; The trumpet shape hole is convenient for connecting rod 9 to adjust the direction.

The outer diameter of the positioning disc 4 is adapted to the inner diameter of the reaction force support seat 5, and the outer edge of the positioning disc 4 is slidingly matched with the inner wall of the reaction force support seat 5, and moves back and forth along the axis of the pull rod 1. After the small brick 11 to be tested is clamped and positioned, the center of the positioning plate 4 is located at the center of the end face of the small brick 11 .

As shown in Figure 3, the spacer 3 with the central through hole is a cuboid, the thickness h is 30 mm to 50 mm, the size of the width B and length L is compatible with the size of the end face of the small brick 11, and the pull rod 1 and the first nut 2 can be passed to each other. The incoming force is evenly distributed on the end face of the small brick 11, so as to prevent the local pressure of the small brick 11 from being sheared and damaged before the measured mortar joint 13.

When in use, the decorative layer on the surface of the masonry to be tested is removed, and the small brick 11 is selected as the site to be tested. In the center of the end face, drill a hole perpendicular to the end face of the small brick 11, and install the clamping part on the small brick according to the order shown in Figure 1, wherein the spacer 3 should be completely attached to the end face of the small brick 11. Insert the spherical protrusion of the connecting rod 9 into the groove of the connecting piece 10 . Pass the reaction force support seat 5 through the connecting rod 9, and set it on the outside of the positioning plate 5, against the surface of the masonry. Connect the dynamometer 7 to the jack 6, turn on the dynamometer 7 and adjust to zero. Put the jack 6 through the connecting rod 9 against the reaction support seat 5, and tighten the second nut 8 at the end of the connecting rod 9. Start the jack 6, pull out the small brick 11 from the masonry, record the maximum pull-out force value and bonding area. The masonry shear strength was calculated from the maximum pull-out force value and bonded area.

Claims (3)

1. a shear strength of masonry testing apparatus, it comprises pull bar, described pull bar comprises head and afterbody, web member is provided with at the head of pull bar, the diameter of web member is greater than the diameter of afterbody, web member end is provided with groove, and slot opening, on the sidewall of web member, is provided with bell mouth shape hole in web member end and is communicated with the groove of web member; The afterbody of pull bar is provided with external thread and coordinates with the first nut, and pull bar is also set with the positioning disk with center through hole and cushion block; Connecting link one end is provided with the ball bumps suitable with the hollow groove on web member, and the other end is provided with the external thread with the second nut screw connection, and connecting link is set with the counter-force supporting seat of hollow structure and the lifting jack of hollow structure; Dynamometer is connected with the sensor electrical be arranged on lifting jack.

2. shear strength of masonry testing apparatus according to claim 1, is characterized in that the internal diameter of the external diameter of positioning disk and counter-force supporting seat is suitable, the outer rim of positioning disk and counter-force supporting seat inwall is sliding joins, and moves back and forth along pull bar axis.

3. shear strength of masonry testing apparatus according to claim 1, it is characterized in that cushion block is rectangular parallelepiped, thickness h is 30mm ~ 50mm.