CN205157405U

CN205157405U - New old concrete bonding interface pure shear experimental apparatus

Info

Publication number: CN205157405U
Application number: CN201520855740.3U
Authority: CN
Inventors: 张雷; 雷冬; 江恩慧; 蒋睿; 王金亮; 郑军; 李贵勋; 姬秀明; 刘平湖
Original assignee: Yellow River Institute of Hydraulic Research
Current assignee: Yellow River Institute of Hydraulic Research
Priority date: 2015-10-30
Filing date: 2015-10-30
Publication date: 2016-04-13
Anticipated expiration: 2025-10-30

Abstract

The utility model relates to a novel experimental device in the field of water conservancy and civil engineering, in particular to a pure shear experimental device for bonding interface between new and old concrete. The pure shear experimental device includes an upper L-shaped clamp, a lower L-shaped clamp, bolts, side chucks, concrete specimens, a test machine base, a test machine pressure head, screws, and springs. The utility model device is small in volume, simple in manufacture, convenient in use, easy to assemble and disassemble, and can conduct shear experiments on concrete under pure shear conditions, test the shear strength of concrete under pure shear action, and analyze the shear force of concrete Performance, provide the shear strength parameters of the bonded interface, use it as a mechanical performance index for the design of concrete structure reinforcement and repair, and provide technical guidance for the treatment of the bonded interface of old and new concrete in concrete reinforcement construction.

Description

Linking new and old concrete interface pure shear experimental provision

Technical field

The utility model relates to a kind of Novel experiment device of water conservancy field of civil engineering, especially linking new and old concrete interface pure shear experimental provision.

Background technology

Concrete, is called for short concrete, refers to the general designation being cemented to overall engineered composite material by Binder Materials by gathering materials.Usually the concrete said refers to and does Binder Materials with cement, and sand, masonry gather materials, and coordinate by a certain percentage with water, additive, admixture, and the cement concrete obtained through stirring is widely used in water conservancy civil engineering work.Under various working load and erosion environment effect, xoncrete structure creates quite serious aging, disease and accident, reduces security and the permanance of structure, has had a strong impact on the normal use of buildings and the safety of national economy.

For so serious existing concrete structure aging diseases phenomenon, the maintenance and reinforcement of xoncrete structure develops rapidly becomes an emerging special engineering industry.In recent years, the investment of China in existing concrete structure maintenance and reinforcement is also very large, 40,800,000,000 yuan of reinforcements for national hydraulic engineering of especially just injecting capital into after extraodinary flood in 1998.At present, for xoncrete structure, the most frequently used and simple and effective reinforcing restorative procedure is section-increased method, namely first disease concrete surface is being had to carry out certain process, as brushing interface adhesive, then, above being cast in by novel concrete, linking new and old concrete is made to become the acting force of as a whole shared original structure.As can be seen here, make new-old concrete really become as a whole come co-operation, then the bonds well performance between new-old concrete interface just becomes its key point.But, in Practical Project, the structure of a lot of repairing and reinforcing after a period of operation, just there is crack in adhesive surface, new benefit concrete also there will be and peels off and crack phenomenon, make integrally-built using function and security again impaired, wherein very important reason is exactly lack systematic study to linking new and old concrete mechanism and mechanical property and understanding, deals with improperly cause linking new and old concrete face.

Test method for linking new and old concrete performance test is a lot, mainly for the test of tensile property and shear behavior.On-the-spot directly tensile test method can directly measure bond quality and intensity at the scene, has accurate and reliable character, is recommended as a kind of standard test method by ACI.The test specimen of shearing strength experiment is the earliest the short beam with two shear surfaces, and the high level perpendicular stress along loading direction in beam on xsect have impact on concrete shearing strength.Afterwards, adopt top and bottom to establish jagged short beam, to slow down the impact of perpendicular stress on shearing strength, but such test specimen is concentrated due to stress, destroys the end points starting from recess, and not in the middle of the maximum xsect of shear stress.In fact, by the shearing experiment result at the linking new and old concrete interface of the test specimen gained of this kind of form, can only say it is staight scissors, but not concrete single shearing strength.

Given this, must design can the test unit of shear resistance of its bonding interface of accurate measurement, it can be used as key property index for concrete structure reinforcement repair capsule, simultaneously for the process at linking new and old concrete interface in concrete strengthening construction provides technological guidance.

Utility model content

The utility model is exactly to solve prior art above shortcomings, pure shear experimental provision in linking new and old concrete interface is provided, this device makes concrete not stress on surface up and down after loading concrete material, front and rear surfaces bears the normal pressure of this device applying and the friction force of vertical direction, thus the shear resistance of test concrete under pure shear effect, analyze concrete shearing stress performance, concrete shearing intensive parameter is provided, can for the structural design of concrete material in Practical Project practice, force analysis reference.

In order to solve the problems of the technologies described above, the utility model is achieved through the following technical solutions:

Linking new and old concrete interface pure shear experimental provision, described linking new and old concrete interface pure shear experimental provision comprises L-type fixture, lower L-type fixture, bolt, side chuck, concrete sample, experimental machine base; Upper L-type fixture stands upside down to place and forms Unseal type square frame-shaped structure with lower L-type fixture, and upper L-type fixture and lower L-type clip vertical direction are stayed at regular intervals; The left and right side that upper L-type fixture and lower L-type fixture form the inside of Unseal type square frame-shaped structure is provided with slideway along the fore-and-aft direction of surface level, side chuck is movably arranged on slideway two ends, side chuck sandwiched concrete sample front-back, bolt wears the fastening concrete sample front-back of side chuck at slideway two ends; Upper L-type clamp top is provided with force loading device; Lower L-type clamp base is fixedly installed on experimental machine base.

Further, the shape of described slideway is cave inward inverse-T-shaped, and the shape of side chuck is " work " font, and one end of side chuck is movably arranged in slideway;

Further, the part that described upper L-type fixture, lower L-type fixture contact with concrete sample is provided with friction structure, to strengthen friction;

Further, described upper L-type fixture, lower L-type fixture, bolt, side chuck utilize friction force that concrete sample is fixed on centre;

Further, described force loading device comprises experimental machine pressure head, screw, spring, experimental machine pressure head is cylindrical sleeve, be connected with the coupling shaft of upper L-type clamp top, coupling shaft and experimental machine pressure head are provided with screw, and coupling shaft screw and experimental machine pressure head screw are coupled together by spring; On the power that force loading device applies is delivered to concrete sample front-back by side chuck and direction and front-back downwards coplanar.

Compared with prior art, the beneficial effects of the utility model are:

The utility model device volume is little, make simple, easy to use, be convenient to assembly and disassembly, linking new and old concrete interface can be made in pure shear situation to carry out shear test, and the shear resistance of test concrete under pure shear effect, analyzes the shearing stress performance at linking new and old concrete interface, there is provided new-old concrete shear strength parameters, for concrete structure reinforcement design provides reference.

Accompanying drawing explanation

Fig. 1 is structural representation of the present utility model.

In figure: the upper L-type fixture of 1-; L-type fixture under 2-; 3-bolt; 4-side chuck; 5-concrete sample; 6-experimental machine base; 7-experimental machine pressure head; 8-screw; 9-spring.

Embodiment

Below in conjunction with accompanying drawing, the utility model is described in further detail.

Embodiment:

When the utility model is applied in and concrete material does the pure shear experiment of linking new and old concrete interface:

As shown in Figure 1, linking new and old concrete interface pure shear experimental provision, described linking new and old concrete interface pure shear experimental provision comprises L-type fixture 1, lower L-type fixture 2, bolt 3, side chuck 4, concrete sample 5, experimental machine base 6; Upper L-type fixture 1 stands upside down to place and forms Unseal type square frame-shaped structure with lower L-type fixture 2, and upper L-type fixture 1 stays at regular intervals with lower L-type fixture 2 vertical direction; The left and right side that upper L-type fixture 1 and lower L-type fixture 2 form the inside of Unseal type square frame-shaped structure is provided with slideway along the fore-and-aft direction of surface level, side chuck 4 is movably arranged on slideway two ends, side chuck 4 sandwiched concrete sample 5 front-back, bolt 3 wears side chuck 4 fastening concrete sample 5 front-back at slideway two ends; Upper L-type fixture 1 top is provided with force loading device; Be fixedly installed on experimental machine base 6 bottom lower L-type fixture 2.

On the basis of technical scheme described in the above embodiments, preferably, the shape of described slideway is cave inward inverse-T-shaped, and the shape of side chuck 4 is " work " font, and one end of side chuck 4 is movably arranged in slideway;

The part that described upper L-type fixture 1, lower L-type fixture 2 contact with concrete sample 5 is provided with friction structure, to strengthen friction;

Described upper L-type fixture 1, lower L-type fixture 2, bolt 3, side chuck 4 utilize friction force that concrete sample 5 is fixed on centre;

Described force loading device comprises experimental machine pressure head 7, screw 8, spring 9, experimental machine pressure head 7 is cylindrical sleeve, be connected with the coupling shaft at upper L-type fixture 1 top, coupling shaft and experimental machine pressure head 7 are provided with screw 8, and coupling shaft screw and experimental machine pressure head screw are coupled together by spring 9; On the power that force loading device applies is delivered to concrete sample 5 front-back by side chuck 4 and direction and front-back downwards coplanar.

When experiment is carried out, experimental machine pressure head 7 oppresses upper L-type fixture 1, and under friction force effect, concrete sample 5 is subject to pure shear and destroys, and tests and analyzes the shear strength of concrete sample 5 under pure shear effect.

In sum, these are only preferred embodiment of the present utility model, be not intended to limit protection domain of the present utility model.All within spirit of the present utility model and principle, any amendment done, equivalent replacement, improvement etc., all should be included within protection domain of the present utility model.

Claims

1. A new and old concrete bond interface pure shear test device, characterized in that: the new and old concrete bond interface pure shear test device comprises an upper L-shaped clamp (1), a lower L-shaped clamp (2), bolts (3 ), side chuck (4), concrete specimen (5), testing machine base (6); the upper L-shaped fixture (1) is placed upside down and the lower L-shaped fixture (2) forms an unclosed box-shaped structure, and the upper There is a certain distance between the L-shaped clamp (1) and the lower L-shaped clamp (2) in the vertical direction; the upper L-shaped clamp (1) and the lower L-shaped clamp (2) form the inner left and right sides of the unclosed box-shaped structure A slideway is provided along the front and back direction of the horizontal plane, and the side clamps (4) are movably arranged at both ends of the slideway, the side clamps (4) clamp the front and back of the concrete specimen (5), and the bolts (3) pass through the slideway. The side chucks (4) at both ends of the road fasten the front and back of the concrete specimen (5); the upper L-shaped clamp (1) is equipped with a force loading device; the bottom of the lower L-shaped clamp (2) is fixed on the base of the testing machine (6) superior.

2. The new-old concrete bond interface pure shear test device according to claim 1, characterized in that: the shape of the slideway is an inverted "T" shape sunken inward, and the shape of the side chuck (4) is "I" shape, one end of the side chuck (4) is movably arranged in the slideway.

3. The new-old concrete bond interface pure shear test device according to claim 1, characterized in that: said upper L-shaped fixture (1), lower L-shaped fixture (2) is in contact with the concrete specimen (5) Some are provided with friction structures.

4. The new-old concrete bonding interface pure shear test device according to claim 1, characterized in that: the force loading device includes a test machine pressure head (7), a screw (8), a spring (9), a test machine The indenter (7) is a cylindrical sleeve, which is connected with the connecting shaft on the top of the upper L-shaped fixture (1). There is a screw (8) on the connecting shaft and the indenter (7) of the experimental machine, and the screw of the connecting shaft is connected with the experimental machine. The machine head screw is connected by a spring (9).