CN-224231453-U - High rigidity UHPC concrete tensile test anchor clamps

Abstract

The utility model relates to a high-rigidity UHPC concrete tensile test fixture which comprises a fixture chuck for clamping the end part of a test piece and a variable cross section connecting rod for connecting the fixture chuck with a tensile test facility, wherein the fixture chuck comprises a top plate, side plates and a variable cross section connecting rod fixing structure, the side plates are respectively arranged on two sides of the same side of the top plate, the side plates are variable cross section plates with gradually shortened lengths from one side close to the top plate to the side far away from the top plate, the sides of the variable cross section plates on the two sides are straight sides, the sides far away from each other are inclined sides, the end of the side plate, far away from the top plate, of the straight sides is respectively provided with the variable cross section connecting rod fixing structure, and the top plate is connected with the variable cross section connecting rod through a variable cross section connecting rod fixing hole formed in the side opposite to the side plate. Compared with the prior art, the clamp provided by the utility model has the characteristic of high rigidity, and can prevent a concrete test block from being broken too fast after the concrete reaches a peak load, and can accurately measure the stress-strain curve of the whole concrete process.

Inventors

• ZHANG MENGQI
• DUAN TING
• LI ZHIBO
• HE RONG
• ZHAO XIUYI
• MA BIAO
• MA LIANXIA
• GUAN ZHONGGUO
• ZHANG PEIJUN
• WU JIANMING
• TIAN RUN
• WANG RUILONG
• CHEN FANG

Assignees

• 同济大学
• 上海市政工程设计研究总院（集团）有限公司
• 新疆交通建设集团股份有限公司

Dates

Publication Date

20260512

Application Date

20250731

Claims (7)

1. 1. The high-rigidity UHPC concrete tensile test clamp is characterized by comprising a clamp chuck (1) for clamping the end part of a concrete test piece (8) and a variable cross-section connecting rod (6) for connecting the clamp chuck (1) with a tensile test facility (7); the clamp chuck (1) comprises a top plate (2), side plates (3) and an arc fixing structure (4); The two side plates (3) are variable cross-section plates with gradually shortened lengths from one side close to the top plate (2) to one side far away from the top plate (2), one side of the variable cross-section plates at the two sides of the top plate (2) is a straight line side, and the other side far away from the top plate is an inclined plane side; The side plates (3) on the two sides of the top plate (2) are respectively provided with an arc fixing structure (4) at one end of the straight line side far away from the top plate (2); The variable cross-section connecting rod fixing hole is formed in one surface of the top plate (2) opposite to the side plate (3), and the variable cross-section connecting rod (6) is connected with the clamp chuck (1) in an installation mode through the variable cross-section connecting rod fixing hole.
2. 2. A high stiffness UHPC concrete tensile testing clamp according to claim 1, characterized in that the clamp variable section connecting rod (6) comprises a threaded section and a polished rod, the clamp variable section connecting rod (6) being fixedly connected to the clamp collet (1) by means of the threaded section and to the tensile testing facility by means of the polished rod.
3. 3. The high stiffness UHPC concrete tensile test fixture of claim 2, wherein the diameter of the shank is greater than the diameter of the threaded section, the threaded section being connected to the shank by a variable diameter cross-section.
4. 4. The high-rigidity UHPC concrete tensile test fixture of claim 2, wherein the surface of the threaded section is provided with external threads, the variable cross-section connecting rod fixing hole is a bolt hole (5), and internal threads matched with the threaded section are arranged in the hole.
5. 5. A high stiffness UHPC concrete tensile test fixture according to claim 4, characterized in that said threaded section is provided with M16 bolts, said bolt holes (5) being provided as M16 bolt holes.
6. 6. The high-rigidity UHPC concrete tensile test fixture of claim 1, wherein the top plate (2) is a steel plate, and the side plates (3) and the top plate (2) are connected through welding.
7. 7. The high-rigidity UHPC concrete tensile test fixture according to claim 1, wherein arc-shaped fixing structures (4) arranged on the side plates (3) at two sides are arc-shaped and matched with the shape of the variable section of the concrete test piece (8).

Description

High rigidity UHPC concrete tensile test anchor clamps Technical Field The utility model relates to the technical field of engineering test devices, in particular to a high-rigidity UHPC concrete tensile test fixture. Background Ultra-high performance concrete (UHPC) is a preferred material for foundation construction upgrading and green construction due to its excellent compressive strength and durability, and is widely applied to bridge reinforcement, assembly type construction, landmark engineering and tunnel repair. Thus, obtaining a stress-strain full curve for UHPC concrete is very important for studying and verifying its performance. When the concrete is in tension test, the internal force of the concrete test block can be rapidly and greatly reduced after the concrete reaches peak load, and the internal force of the clamp can be rapidly reduced. The elastic potential energy of the clamp is converted into plastic deformation energy of the concrete test piece. For example, the tensile test clamp disclosed in chinese patent application CN108918256A, CN207095976U and the like has low general rigidity, and large elastic energy storage, which causes too fast plastic deformation of concrete and too fast fracture of concrete test piece, so it is difficult to accurately measure the concrete stress-strain whole process curve. Disclosure of utility model The utility model aims to solve the problems that the elastic energy storage of the existing clamp is large, so that the plastic deformation of concrete is too fast, and the whole process of concrete stress-strain is difficult to accurately measure, and provides a high-rigidity UHPC concrete tensile test clamp. The aim of the utility model can be achieved by the following technical scheme: A high-rigidity UHPC concrete tensile test clamp comprises a clamp chuck for clamping the end part of a concrete test piece and a variable cross-section connecting rod for connecting the clamp chuck with a tensile test facility; The clamp chuck comprises a top plate, side plates and an arc fixing structure; The two side plates are variable cross-section plates with the length gradually shortened from one side close to the top plate to the side far away from the top plate, the mutually facing sides of the variable cross-section plates at the two sides of the top plate are straight sides, and the mutually far away sides are inclined sides; The side plates at the two sides of the top plate are respectively provided with an arc fixing structure at one end of the straight line side far away from the top plate; The variable cross-section connecting rod is connected with the clamp chuck in an installation way through the variable cross-section connecting rod fixing hole. As the preferable technical scheme, the fixture variable cross-section connecting rod comprises a threaded section and a polished rod, wherein the fixture variable cross-section connecting rod is fixedly connected with a fixture chuck through the threaded section and is connected with a tensile test facility through the polished rod. As a preferred solution, the diameter of the rod is larger than the diameter of the threaded section, and the threaded section is connected with the rod through a variable diameter section. The variable cross-section connecting rod fixing hole is a bolt hole, and an internal thread matched with the threaded section is arranged in the hole. As a preferred solution, the threaded section employs M16 bolts, which are provided as M16 bolt holes. As the preferable technical scheme, the top plate is a steel plate, and the side plates are connected with the top plate through welding. As the preferable technical scheme, the arc-shaped fixing structures arranged on the side plates at the two sides are arc-shaped and matched with the shape of the variable section of the concrete test piece. Compared with the prior art, the utility model has the following beneficial effects: 1) A high-rigidity UHPC concrete tensile property test fixture. The clamp clamping head with the equal-strength structure and the structural design of the variable-section connecting rod are adopted, so that the clamp stress can be reduced, the rigidity of the test clamp is improved, the elastic energy storage of the clamp is reduced, and the concrete test piece is prevented from being broken too quickly. Therefore, the concrete stress-strain whole process curve can be accurately measured. 2) The clamp chuck designed by the utility model can effectively reduce the stress of the clamp chuck, improve the rigidity of the clamp chuck and reduce the elastic energy storage of the clamp chuck by about 70 percent. The rigidity is ensured to be improved, and meanwhile, the clamp chuck material can be saved. 3) The lower part of the variable cross-section connecting rod is designed as a bolt M16, and the small diameter reduces the additional bending moment. The upper part of the variable cross-section connecting rod is designed into a p