Uniaxial tensile testing device for high-strength fiber concrete

Abstract

The utility model belongs to the technical field of concrete performance testing, and particularly relates to a uniaxial tensile testing device for high-strength fiber concrete. The device comprises two frames of a [-shaped structure, first bolts are arranged on the frames, a first fixing plate is horizontally fixed on the side wall of the upper frame, a first fixing plate is horizontally fixed on the lower frame, a dial indicator is arranged between a second fixing plate and the first fixing plate, an adjusting mechanism for adjusting the distance between the first fixing plate and the dial indicator is arranged on the first fixing plate, and a second fixing plate is arranged on the second fixing plate. The top of the second fixing plate is provided with a groove for insertion of a measuring head of the dial indicator and up-down sliding. According to the design, the frame and the test piece are fixed through the first bolt, and the distance between the dial indicator and the first fixing plate is adjusted, so that the measuring head of the dial indicator is always located at the bottom of the groove of the second fixing plate, and the dial indicator can conveniently test the test piece.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the technical field of concrete performance test, especially relate to a high -strength fiber concrete uniaxial tension testing device. BACKGROUND

[0002] Concrete as the important component of civil engineering industry, has the role that can not be ignored in various projects, and the key problems such as weak tensile strength, low crack resistance and poor ductility of ordinary concrete and its characteristics limit its application in building, in order to improve its toughness and reduce brittleness, high-strength fiber concrete emerges as the times require, high-strength fiber concrete is a kind of cement-based material with good application prospect, has higher compressive strength, tensile strength, ductility and energy absorption capacity, so compared with ordinary concrete material, the uniaxial tensile property of high-strength fiber concrete is more important.

[0003] Therefore, how to obtain the uniaxial tensile stress-strain relationship of high-strength fiber concrete through test is of great significance to the mechanical property evaluation, design, parameter selection of finite element software analysis and popularization and application of high-strength fiber concrete, in order to study the tensile property of high-strength fiber concrete, the common test methods are splitting tensile test, bending test and direct uniaxial tensile test, among them, uniaxial tensile test can directly obtain the tensile strength of high-strength fiber concrete and the tensile stress-strain curve of high-strength fiber concrete material, is the most direct and effective method to reflect the real synergy of matrix and fiber in concrete, and plays an important role in determining structural design parameters.

[0004] At present, the test piece of concrete uniaxial tensile test can be divided into two types of notched and unnotched, and the unnotched is closer to the real axial tensile stress state and is used more, in addition, the shape of uniaxial tensile test piece mainly has dog bone type, cylinder and prism, and the application frequency of dog bone type uniaxial tensile test piece is higher, when testing, two clamps are used to clamp the two ends of the dog bone type test piece, then the clamps are connected with the upper and lower mechanical loading ends of the test equipment through universal joint, the LVDT displacement system for collecting instantaneous strain and total strain of the test piece is connected on the test piece, generally collected by micro-deformation measuring instrument, such as micrometer and displacement sensor, at present, the micrometer is fixed on the test piece by the fixing frame, the connection of the fixing frame and the micrometer is inconvenient, the up-down position of the micrometer cannot be adjusted according to the actual situation, so that the test is inconvenient, and the installation is more troublesome. UTILITY MODEL CONTENTS

[0005] The utility model aims at providing a kind of high-strength fiber concrete uniaxial tensile testing device, it is convenient to install micrometer on test piece, and micrometer can be adjusted, so that micrometer is convenient to test test piece.

[0006] The high-strength fiber concrete uniaxial tension testing device, comprising two horizontally arranged and up-down distributed frames, the two frames are both in the shape of " " structure, a first bolt is arranged on the frame to fix the frame with a test piece, a first fixed plate is horizontally fixed on the side wall close to the opening of the upper frame, a first fixed plate is horizontally fixed on the lower frame corresponding to the first fixed plate, a micrometer is arranged between the second fixed plate and the first fixed plate, an adjusting mechanism is arranged on the first fixed plate to adjust the distance between the first fixed plate and the micrometer, and a groove is formed in the top of the second fixed plate for the insertion and up-down sliding of the measuring head of the micrometer.

[0007] Further, the frame has no left side wall, the first bolt is provided with four, two by two groups are respectively located on the front and rear side walls of the frame.

[0008] Further, the left side of the frame is detachably provided with a fixing rod, and the right side wall of the frame is provided with a second bolt.

[0009] Further, the two ends of the fixing rod are provided with external threads, and the two ends of the fixing rod are provided with first nuts in threaded connection with the two ends, and the end of the first nut is provided with a placing groove for the end of the fixing rod.

[0010] Further, the fixing rod is divided into two sections, which are fixed through a connecting rod, the length of the connecting rod is consistent with the inner width of the frame, and the diameter of the fixing rod is smaller than that of the connecting rod.

[0011] Further, the placing groove is formed in the left end face of the frame.

[0012] Further, the first fixed plate and the second fixed plate are both provided with two, which are respectively fixed on the front and rear sides of the frame, and the micrometer is arranged between the first fixed plate and the second fixed plate.

[0013] Further, the adjusting mechanism comprises a fixed shaft vertically fixed on the top of the micrometer, a first through hole is formed in the first fixed plate for the fixed shaft to pass through and move up and down, and a third bolt is arranged on the first fixed plate to fix the fixed shaft in the first through hole.

[0014] Further, a second fixed column is vertically arranged between the two frames, the bottom end of the second fixed column is connected with the top of the lower frame, the top end of the second fixed column is vertically fixed with a first fixed column, the diameter of the first fixed column is smaller than that of the second fixed column, and a second through hole is formed in the upper frame for the first fixed column to pass through and move up and down.

[0015] Further, a screw rod is vertically fixed on the bottom of the second fixed column, the diameter of the screw rod is smaller than that of the second fixed column, a third through hole is formed in the lower frame for the screw rod to pass through, and a second nut is arranged on the screw rod in threaded connection with the screw rod.

[0016] Compared with the prior art, the utility model has the following beneficial effects:

[0017] The utility model discloses a frame and test piece are fixed through first bolt, and two frames are all fixed at the optimum position of test piece, and the distance of dial gauge and first fixed plate is adjusted, makes the measuring head of dial gauge always be located at the recess bottom of second fixed plate, thereby conveniently test piece is tested to dial gauge. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 It is the structure schematic diagram of the utility model;

[0019] Figure 2 It is the top structure schematic diagram of Figure 1 ;

[0020] Figure 3 It is the use state diagram of the utility model;

[0021] The component name in drawing: 1, frame;2, second bolt;3, first bolt;4, third bolt;5, fixed shaft;6, first fixed plate;7, first fixed column;8, fixed rod;9, first nut;10, second fixed column;11, second nut;12, second fixed plate;13, fixed block;14, dial gauge;15, connecting rod;16, clamp;17, test piece. DETAILED DESCRIPTION

[0022] The utility model is further described below by specific embodiment in combination with the drawings, but is not used to limit the utility model, and any modification, equivalent replacement, improvement etc. that is made within the spirit and principle of the utility model should be included in the protection scope of the utility model.

[0023] The high-strength fiber concrete uniaxial tensile testing device described in the embodiment, as shown in Figure 1 And Figure 2 It includes two horizontally arranged and upper and lower distributed frames 1, the frame 1 is overall " " type structure, the frame 1 is provided with first bolt 3 for fixing it with test piece, the upper frame 1 is fixed with first fixed plate 6 on the side wall close to its opening, if the opening of frame 1 faces left and right, then first fixed plate 6 is fixed on the front and back two sides of frame 1, corresponding first fixed plate 6 is fixed with second fixed plate 12 on the side wall close to the opening of lower frame 1, and second fixed plate 12 is located directly below first fixed plate 6.

[0024] The frame 1 has no left side wall, and the first bolt 3 is provided with 4, and two groups are located on the front and back side walls of the frame 1, and the frame 1 can be better fixed on the test piece 17 through the 4 first bolts 3.

[0025] The left side of the frame 1 is detachably provided with a fixing rod 8, and the right side wall of the frame 1 is provided with a second bolt 2, the fixing rod 8 is attached to the test piece 17 through the second bolt 2, so that the frame 1 is fixed with the test piece 17, and the frame 1 forms a closed rectangular frame, thereby reducing the left and right inclination of the frame 1, in order to increase the fixing effect, the second bolt 2 is provided with two.

[0026] Both ends of the fixing rod 8 are provided with external threads, and both ends of the fixing rod 8 are provided with first nuts 9 which are threadedly matched with the fixing rod 8, the end of the first nut 9 is provided with a placing groove for inserting the fixing rod 8, and the fixing rod 8 is connected with the frame 1 through the two first nuts 9 which are tightly attached to the front and rear sides of the frame 1, so that the fixing rod 8 and the frame 1 are detachably connected.

[0027] The fixing rod 8 is divided into two sections, which are fixed by a connecting rod 15, the length of the connecting rod 15 is consistent with the inner width of the frame 1, and the diameter of the fixing rod 8 is smaller than the diameter of the connecting rod 15, and the diameter of the placing groove is smaller than the diameter of the connecting rod 15, so that the connecting rod 15 can prevent the front and rear sliding and increase the fixing effect.

[0028] The placing groove is provided on the left end face of the frame 1, and the placing groove is in a "C" type structure, so that the fixing rod 8 can be horizontally placed in the placing groove, of course, the placing groove can also be provided on the top of the left side of the frame 1, and the fixing rod 8 can be placed in the placing groove from the top.

[0029] The second fixing plate 12 and the first fixing plate 6 are provided with a dial gauge 14, the top of the second fixing plate 12 is provided with a groove for inserting and sliding up and down the measuring head of the dial gauge 14, and the depth of the groove meets the moving distance of the measuring head of the dial gauge 14, when the test piece 17 is stretched, the movement of the test piece 17 drives the two frames 1 to move, so that the measuring head of the test piece 17 moves in the groove, when the test piece 17 breaks, the measuring head of the dial gauge 14 is still in the groove, in order to increase the depth of the groove, a fixed block 13 is fixed on the top of the second fixing plate 12, and a through hole is formed in the fixed block 13, the depth of the groove is increased through the through hole of the fixed block 13.

[0030] The first fixing plate 6 and the second fixing plate 12 are provided with two plates respectively fixed on the front and rear sides of the frame 1, and the dial gauge 14 is arranged between the first fixing plate 6 and the second fixing plate 12, so that the front and rear sides of the test piece 17 can be tested through the two dial gauges 14, so that the result is more accurate.

[0031] The top of the dial gauge 14 is vertically fixed with a fixed shaft 5, the measuring head of the dial gauge 14 is located below, the first fixed plate 6 is provided with a first through hole for the fixed shaft 5 to pass through and move up and down, the first fixed plate 6 is provided with a third bolt 4 for fixing the fixed shaft 5 in the first through hole, the side wall of the first fixed plate 6 is provided with a threaded hole in threaded cooperation with the screw rod of the third bolt 4, the threaded hole is connected and communicated with the first through hole, the dial gauge 14 is slid up and down by the fixed shaft 5 sliding up and down in the first through hole; of course, in some embodiments, the first fixed plate 6 can also not be provided with the first through hole, and a fixed tube is sleeved on the fixed shaft 5, the fixed tube is fixed with the bottom of the first fixed plate 6, and the fixed tube is provided with a bolt. The whole part constitutes an adjusting mechanism for adjusting the distance between the first fixed plate 6 and the dial gauge 14.

[0032] The second fixed column 10 is vertically arranged between the two frames, the second fixed column 10 is vertically provided with four feet, two feet in each group are respectively located between the front and rear side walls of the frame 1, the bottom end of the second fixed column 10 is connected with the top of the lower frame 1, the top end of the second fixed column 10 is vertically fixed with the first fixed column 7, the diameter of the first fixed column 7 is smaller than the diameter of the second fixed column 10, the upper frame 1 is provided with a second through hole for the first fixed column 7 to pass through and move up and down, the upper frame 1 is supported by the second fixed column 10, and the first fixed column 7 in the second through hole can reduce the deviation of the two frames 1 during the up and down movement; of course, in some embodiments, a fixed tube can also be sleeved on the second fixed column 10, the second fixed column 10 is fixed with the top of the lower frame 1, the fixed tube is fixed with the bottom of the upper frame 1, and the second fixed column 10 freely slides up and down in the fixed tube, and the second fixed column 10 and the fixed tube can also reduce the deviation of the frame 1.

[0033] The bottom of the second fixed column 10 is vertically fixed with a screw rod, the diameter of the screw rod is smaller than the diameter of the second fixed column 10, the lower frame 1 is provided with a third through hole for the screw rod to pass through, the screw rod is provided with a second nut 11 in threaded cooperation therewith, the second fixed column 10 can be fixed on the top of the lower frame 1 by the second nut 11 and the screw rod, and the second fixed column 10 and the lower frame 1 can be detachably cooperated. The working principle and technical effect of the embodiment are as follows:

[0034] In use, as Figure 3As shown, after the test piece 17 is poured, it is clamped by the clamp 16, and the connecting head is fixed on the top of the upper clamp 16 and the bottom of the lower clamp 16. The connecting head is connected with the test equipment through the bolt, then the fixed rod 8 is taken off from the left side of the frame 1, the lower frame 1 is sleeved on the bottom end of the test section of the test piece 17, then the lower frame 1 is fixed with the test piece 17 through the first bolt 3. When the frame 1 is fixed through the first bolt 3, the distance between the front and rear sidewalls of the frame 1 and the test piece 17 is consistent, which reduces the deviation of the frame 1 during stretching. Then the second fixed column 10 is connected to the lower frame 1, the upper frame 1 is sleeved on the top end of the test section of the test piece 17, then the micrometer 14 is inserted into the groove on the top of the second fixed plate 12 through the up-and-down movement of the fixed shaft 5 on the first fixed plate 6, and the probe of the micrometer 14 is in contact with the bottom of the groove. The distance between the micrometer 14 and the first fixed plate 6 is adjusted by moving the fixed shaft 5 in the through hole of the first fixed plate 6, so that the positions of the two frames 1 can be adjusted to make the probe of the micrometer 14 located at the bottom of the groove. Then the upper frame 1 is fixed with the test piece 17 through the first bolt 3, the fixed rod 8 is connected to the left end of the frame 1 through the first nut 9, and the fixed rod 8 is in contact with the test piece 17 through the second bolt 2, which also reduces the deviation of the frame 1 during stretching. The data line of the micrometer 14 is installed, the strain data acquisition instrument and the computer are connected, the test equipment is loaded with pre-tightening force at the beginning of the test, the appropriate displacement loading rate is selected, the accuracy of the test data and the rationality of the data acquisition are checked, and the test equipment, the data acquisition instrument and the computer are debugged. After the stretching test is started, the test data is recorded until the test piece 17 is stretched and broken, the test is stopped, the test data is saved and statistics are made, the stress is obtained by dividing the force of the force-displacement curve by the cross-sectional area of the concrete test piece, and the strain of the concrete is obtained by dividing the displacement of the force-displacement curve by the distance of the middle measuring section, that is, the uniaxial tensile stress-strain full curve of the high-strength fiber concrete is obtained.

Claims

1. A uniaxial tensile testing device for high-strength fiber reinforced concrete, comprising two horizontally arranged and vertically distributed frames (1), characterized in that... : The two frames (1) are both in a "C"-shaped structure. A first bolt (3) for fixing it to the test piece is provided on the frame (1). A first fixing plate (6) is horizontally fixed on the side wall of the upper frame (1) near its opening. A first fixing plate (6) is horizontally fixed on the lower frame (1) corresponding to the first fixing plate (6). A dial indicator (14) is provided between the second fixing plate (12) and the first fixing plate (6). An adjusting mechanism for adjusting the distance between it and the dial indicator (14) is provided on the first fixing plate (6). A groove for the probe of the dial indicator (14) to insert and slide up and down is opened at the top of the second fixing plate (12).

2. The high-strength fiber reinforced concrete uniaxial tensile testing device according to claim 1, characterized in that: The frame (1) has no left side wall. There are 4 first bolts (3), and two in a group are respectively located on the front and rear side walls of the frame (1).

3. The high-strength fiber reinforced concrete uniaxial tensile testing device according to claim 2, characterized in that: A fixing rod (8) is detachably provided on the left side of the frame (1). A second bolt (2) is provided on the right side wall of the frame (1).

4. The high-strength fiber reinforced concrete uniaxial tensile testing device according to claim 3, characterized in that: External threads are opened at both ends of the fixing rod (8). First nuts (9) in threaded fit with it are provided at both ends of the fixing rod (8). A placing groove for the end of the fixing rod (8) to be placed is opened at the end of the first nut (9).

5. The high-strength fiber reinforced concrete uniaxial tensile testing device according to claim 4, characterized in that: The fixing rod (8) is divided into two sections, and it is fixed by a connecting rod (15). The length of the connecting rod (15) is the same as the inner width of the frame (1), and the diameter of the fixing rod (8) is smaller than the diameter of the connecting rod (15).

6. The high-strength fiber reinforced concrete uniaxial tensile testing device according to claim 5, characterized in that: The placing groove is opened on the left end face of the frame (1).

7. The high-strength fiber reinforced concrete uniaxial tensile testing device according to claim 1 or 6, characterized in that: Two first fixing plates (6) and two second fixing plates (12) are provided, and they are respectively fixed on the front and rear sides of the frame (1). A dial indicator (14) is provided between the first fixing plate (6) and the second fixing plate (12).

8. The high-strength fiber reinforced concrete uniaxial tensile testing device according to claim 7, characterized in that: The adjusting mechanism includes a fixing shaft (5) vertically fixed on the top of the dial indicator (14). A first through hole for the fixing shaft (5) to pass through and move up and down is opened on the first fixing plate (6). A third bolt (4) for fixing the fixing shaft (5) in the first through hole is provided on the first fixing plate (6).

9. The high-strength fiber reinforced concrete uniaxial tensile testing device according to claim 8, characterized in that: A second fixing column (10) is vertically provided between the two frames. The bottom end of the second fixing column (10) is connected to the top of the lower frame (1). A first fixing column (7) is vertically fixed at the top end of the second fixing column (10). The diameter of the first fixing column (7) is smaller than the diameter of the second fixing column (10). A second through hole for the first fixing column (7) to pass through and move up and down is opened on the upper frame (1).

10. The high-strength fiber reinforced concrete uniaxial tensile testing device according to claim 9, characterized in that: A screw rod is vertically fixed at the bottom of the second fixing column (10). The diameter of the screw rod is smaller than the diameter of the second fixing column (10). A third through hole for the screw rod to pass through is opened on the lower frame (1). A second nut (11) in threaded fit with it is provided on the screw rod.

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