CN206756569U - A kind of band level modulus of elasticity of concrete measure device - Google Patents

Abstract

The utility model discloses a kind of band level modulus of elasticity of concrete measure device, including upper ring and a lower ring, the upper ring and a lower ring is arranged up and down, and upper ring and a lower ring is both provided with fixing the fastener of detected concrete；Circular bubble is additionally provided with the upper ring, location-plate is fixed between upper ring and a lower ring, the location-plate is used for fixed upper the distance between ring and lower ring；Dial indicators rack is provided with upper ring, is provided with contact bar on lower ring, dial indicators rack is used to place amesdial between bar with contacting.The simple generous, low manufacture cost of the utility model device appearance, service efficiency are high, easily operated, practical, safety and environmental protection.

Description

A measuring device for elastic modulus of concrete with level

technical field

The utility model relates to the field of concrete performance testing, in particular to a measuring device for elastic modulus of concrete with a level.

Background technique

The compressive modulus of elasticity is the stress required to produce unit deformation when a prism or cylinder specimen is subjected to a certain axial pressure. When measuring the compressive elastic modulus of cement concrete, two dial gauges are fixed between the fixed frames with a gauge distance of 150mm for micro-deformation measurement, and the value of the compressive elastic modulus of cement concrete is obtained through calculation, which is suitable for engineering fields Modulus of elasticity test for concrete specimens.

The concrete elastic modulus index is an important parameter of concrete engineering in the engineering field, especially in high-span, prestressed structures, and high-strength concrete. It is an important parameter to guide concrete construction. The concrete elastic modulus test process is complicated and time-consuming. The test is carried out after 28 days of specimen production. If the data of the three specimens exceeds the specification requirements, the test results will be invalid, resulting in no parameters for on-site construction, and the loss and processing costs will be greatly increased. Construction costs.

At present, the elastic modulus devices used in the market are all composed of upper and lower rings, contact rods, dial gauges, etc. During the test, the tester measures the gauge line marking position on the test piece, and then the tester installs the upper and lower rings at the positioning position, because The upper and lower rings are fixed by 8 fastening screws, and it is difficult for the tester to fix them at the same time, resulting in that the gauge distance between the upper and lower rings cannot be accurate to 150mm, and the inaccuracy of the gauge distance will directly affect the size of the test results; The non-parallelism of the test directly leads to the fact that the centering step does not meet the specification requirements during the test. The tester will dismantle the device and reassemble it again. This is time-consuming and labor-intensive, and the elastic modulus parameters of the concrete cannot be accurately measured.

In the construction of Jiangxi Expressway, the prefabricated T-beams and cast-in-place box girders in the bridge engineering both have design requirements for the concrete elastic modulus, which is 3.45×10 ⁴ MPa, and the elastic modulus is not less than 90% of the design value, the total design of prefabricated T-beams on Jiangxi Expressway is more than 2600 pieces, and the cast-in-place box girders have also reached more than 500 joints. According to the design, the concrete elastic modulus test will reach more than 6200 groups (28 days old and One group for each tension age) and above, it is the key to quickly and accurately detect the elastic modulus data of concrete.

In the existing technology, there are some deficiencies: 1) It takes a long time to measure the gauge distance marking line on the test piece, and it takes a long time to locate it, and the influence of human factors is relatively large, so it is impossible to quickly and effectively fix the upper and lower rings and the gauge distance is accurate. 2) The level of the fixing frame after fixing depends entirely on the observation and experience of the human eye, and it is impossible to measure the level scientifically and accurately, which has a great influence on the subsequent test process and test data. 3) The contact rod is either fixed or not, directly adjust the height of the dial gauge to contact it, and the dial gauge cannot be quickly installed and reset to zero.

Utility model content

The technical problem to be solved by the utility model is to provide a measuring device for elastic modulus of concrete with a level, which has a simple and generous appearance, low manufacturing cost, high use efficiency, easy operation, strong practicability, safety and environmental protection.

In order to solve the problems of the technologies described above, the technical solution adopted in the utility model is:

A measuring device for elastic modulus of concrete with a level, comprising an upper ring and a lower ring, the upper ring and the lower ring are arranged up and down, and both the upper ring and the lower ring are provided with fastening devices for fixing the concrete to be measured; the upper ring A circular level is also arranged on the upper ring, and a positioning plate is fixed between the upper ring and the lower ring. The positioning plate is used to fix the distance between the upper ring and the lower ring; A contact rod is arranged on the ring, and the dial gauge is placed between the dial indicator bracket and the contact rod.

Further, the fastening device is set screws respectively arranged around the upper ring and the lower ring.

Further, the positioning plate is connected with the upper ring through a positioning bolt, and the positioning plate is connected with the lower ring through a positioning screw.

Further, the dial gauge support is set in the reserved hole of the upper ring, and the contact rod is set in the reserved hole of the lower ring.

Further, a bottom plate is fixed at the lower end of the positioning plate.

Further, the set screws are evenly distributed around the upper ring or the lower ring.

Further, there are two positioning plates.

Compared with the prior art, the utility model has the beneficial effects as follows: 1) It can be used not only as a test device, but also as a teaching instrument. 2) The positioning plate can quickly and accurately locate, ensure the accuracy of the gauge distance of 150mm, and improve the accuracy of the test data at the same time. 3) The installation angle and size of the circular level are conducive to the development of the test work, and it has two functions (locating and centering, and observing the direction of deformation). 4) The U-shaped design of the dial gauge bracket can meet the dial gauge’s arbitrary rotation at any angle and meet the requirements for quick installation of the dial gauge. 5) The device shortens the working time and improves the working efficiency.

Description of drawings

Fig. 1 is the overall structure schematic diagram of the utility model device.

Fig. 2 is a top view of the utility model device.

Fig. 3 is a structural schematic diagram of the fixed part of the device of the present invention.

Fig. 4 is a structural schematic diagram of the reading part of the device of the present invention.

Fig. 5 is a structural schematic diagram of the positioning part of the device of the present invention.

In the figure: 1-Circular level; 2-Set screw; 3-Positioning bolt; 4-Dial indicator bracket; 5-Dial indicator; 6-Positioning plate; 7-Setting screw; 8-Lower ring; Upper ring; 10-contact rod; 11-bottom plate.

detailed description

The utility model is described in detail below through specific embodiments. The utility model device is mainly composed of three major parts: the fixed part, including the upper ring 9 (two circular levels 1 are installed inside), the lower ring 8 (two circular levels 1 can also be installed), the set screw 2; the reading The part includes the dial indicator 5, the contact rod 10 and the dial indicator bracket 4; the positioning part includes the positioning plate 6 and the positioning screw 7.

1. Design and processing of fixed frame

1. Implementation

1) The upper ring 9 and the lower ring 8 with an outer diameter of 258mm (inner diameter 222mm) are made of high-strength stainless steel with a thickness of 20mm and a width of 18mm, which is corrosion-resistant, not easy to rust and deform, and then made of stainless steel with the same material and 8 pieces of Ф10mm in length not less than 85mm set screw 2.

2) Drill holes at 0°, 90°, 180°, and 270° in the thickness direction of the upper ring 9 and the lower ring 8 respectively, which can fasten nuts with Ф10mm screws, and can be used together with 8 set screws 2; Holes Ф5mm at 45° and 225° in the thickness direction, reserved positioning holes on the positioning plate 6, holes Ф8mm at 45° and 225° in the thickness direction of the lower ring 8, and nuts matched with the positioning screws 7.

3) Reserve 4 holes for Ф10mm fixed dial indicator bracket at 165° and 345° in the width direction of upper ring 9, and reserve 10 holes for Ф8mm fixed contact rod at 165° and 345° in the width direction of lower ring 8.

4) Install four circular vial holes of Ф12mm×8mm in the 135° and 315° directions of the width direction of the upper ring 9 and the lower ring 8 .

2. Actual effect verification

1) High-strength stainless steel is superior to ordinary steel in terms of rigidity and hardness, and the upper and lower rings are not easily deformed and damaged. 2) Hole opening and thread processing are all processed by CNC lathe, which increases the precision of device processing. 3) After being fixed, it can be closely combined with other components to achieve the desired effect. 4) It can be quickly installed and positioned to meet the design requirements. 5) It can firmly grasp the specimen and play the role of transmitting strain.

2. Reading system design and processing

1. Implementation

1) Dial gauge 5 is produced by other manufacturers and purchased for use.

2) The contact rod 10 is composed of an upper plate of Ф15mm and a Ф8mm screw rod on the lower part, and is used in conjunction with the Ф8mm fixed contact rod hole reserved for the width direction of the lower ring 8 at 165° and 345°.

3) Dial indicator bracket 4 is composed of two deep U-shaped, the material is consistent with the upper ring 9 and lower ring 8, the total length is 108mm, the thickness is 9mm, and the width is 24mm. The upper and upper ring width directions 165° and 345° are reserved for Ф10mm The holes are fixed, and the bottom is used to fix the dial indicator 5.

2. Actual effect verification

1) The dial indicator support 4 and the contact rod 10 are made of high-strength stainless steel, and the deformation is small during the test, which is closer to the real situation. 2) The installation direction and the installation up and down distance of the dial indicator 5 are not restricted, and can be installed and fastened quickly. 3) The contact rod 10 can rotate up and down to contact with the dial gauge 5 to transmit the strain.

3. Design and processing of positioning device

1. Implementation

1) Two positioning plates 6 are used, which are made of the same stainless steel material as the upper ring 9 and the lower ring 8. The positioning plate 6 is 25 mm wide, 235 mm high (including the thickness of the bottom plate 11), and 4 mm thick; the welding length of the positioning plate 6 is 48 mm. The bottom plate 11 with a width of 12mm can make the positioning plate 6 more stable. Open a Ф8mm screw hole on the positioning plate 6 at a height of 75mm from the ground, and align with the Ф8mm hole at the 45° and 225° thickness directions of the lower ring 8 . Weld a Ф5mm positioning bolt 3 at a height of 225mm from the ground on the positioning plate 6, and use it with the Ф5mm hole in the thickness direction of the upper ring 9 at 45° and 225°.

2) Two positioning screws 7 are used, which are made of the same stainless steel material as the upper ring 9 and the lower ring 8. The length of the screw Ф8mm is not more than 20mm. Both 45° and 225° openings and Ф8mm screw holes can be used together.

2. Actual effect verification

1) Using the positioning board for positioning can solve the problem of rapid positioning, reduce the steps of the tester to measure the gauge distance and mark the positioning on the test piece, and save working time. 2) The positioning bolt 3 and the reserved holes of the upper ring 9 can be quickly disassembled and assembled, saving time. 3) The bottom plate 11 of the positioning plate 6 can make the whole device "stand" independently, which is beneficial to teaching and experiment work.

4. Final Assembly and Verification

1. Final assembly

1) Screw 8 set screws 2 into the reserved nut holes of 0°, 90°, 180°, and 270° in the thickness direction of the upper ring 9 and the lower ring 8, so that the connection is tight and can be in good contact with the test piece , plays the role of fixing the upper and lower rings.

2) Positioning plate 6 is 225mmФ5mm high from the ground, and it is connected with the 45° and 225° reserved holes in the thickness direction of upper ring 9. It is used for the 45° and 225° reserved holes in the thickness direction of the lower ring 8, and is connected with the set screw 7, and the connection is tight and firm.

3) Fix the dial gauge bracket 4 at the reserved holes at 165° and 345° in the width direction of the upper ring 9, and fix the contact rod 10 at the reserved holes at 165° and 345° in the width direction of the lower ring 8.

4) Install the dial gauge 5 on the dial gauge bracket 4, the installation is firm, and the pointer of the dial gauge 5 can move freely.

5) Ensure that the circular level 1 is installed horizontally, and then seal the surrounding area.

6) There are many openings and welds in the device, which should be polished.

7) The whole device should be processed by removing edges and corners to prevent scratching the test personnel. After the completion, the upper ring 9, the lower ring 8, and the positioning plate 6 should be sprayed with a layer of baking paint to prevent oxidation and corrosion from long-term exposure to the air, and the appearance can be more beautiful. Spend.

8) After the assembly is completed, the weight of the whole device is about 3.2kg, and the overall dimensions are 310mm long x 310mm wide x 260mm high.

2. Verification of the final actual effect

After all the assembly is completed, the tester uses a leveled concrete elastic modulus measuring device to measure the elastic modulus of a group of C50 concrete. During use, it can be quickly positioned at one time, and the intermediate gauge distance is 150mm, which is basically error-free. The circular level 1 is used for horizontal positioning. Finally, during the centering test, the error of the dial indicators on both sides is only 0.002mm, which meets the requirements of the specification. The entire test process (from taking out the test piece to the end of all tests) takes 70 minutes.

The same tester took a group of C50 concrete samples on the same day to conduct the elastic modulus test. Using the common elastic modulus measuring device on the market, the tester took up to 10 minutes to position the gauge length, and then centered the test process The error of the dial indicator 5 on both sides of the center has always been above 0.015mm. The tester reassembled it after reassembly, which was time-consuming and laborious. In the final test result, the difference between the axial compressive strength and the average value after one cycle exceeded 20%, and the remaining two The average value of the elastic modulus of the root is taken as the measured value, and the test process takes 120 minutes. From the comparative test process, the use of the measuring device for the elastic modulus of concrete with a level saves more than 50% of the time, and the workload of the tester is relatively small , basically achieve a successful test, and there will be no repeated disassembly and assembly.

Claims (7)

1. a kind of band level concrete modulus of elasticity measuring device is characterized in that, comprises upper ring (9) and lower ring (8), and described upper ring (9) and lower ring (8) are arranged up and down, and upper ring ( 9) and the lower ring (8) are both provided with fastening devices for fixing the concrete to be tested; A circular level (1) is also arranged on the upper ring (9), and a positioning plate (6) is fixed between the upper ring (9) and the lower ring (8), and the positioning plate (6) is used for fixing the distance between the upper ring (9) and the lower ring (8); A dial indicator bracket (4) is arranged on the upper ring (9), and a contact rod (10) is arranged on the lower ring (8). The dial indicator bracket (4) and the contact rod (10) are used to place a dial sub-table (5). 2. a kind of band level concrete modulus of elasticity measuring device as claimed in claim 1, is characterized in that, described fastening device is the set screw ( 2). 3. A kind of band level concrete modulus of elasticity measuring device as claimed in claim 1, is characterized in that, described locating plate (6) links to each other with upper ring (9) by locating bolt (3), and locating plate (6) It is connected with the lower ring (8) through the set screw (7). 4. a kind of band level concrete modulus of elasticity measuring device as claimed in claim 1, is characterized in that, described dial indicator support (4) is arranged in the reserved hole of upper ring (9), and described contact rod (10) is arranged in the reserved hole of lower ring (8). 5. A measuring device for elastic modulus of concrete with level as claimed in claim 1, characterized in that a bottom plate (11) is fixed at the lower end of the positioning plate (6). 6. A measuring device for elastic modulus of concrete with level as claimed in claim 2, characterized in that said set screws (2) are evenly distributed around the upper ring (9) or the lower ring (8). 7. A kind of measuring device for elastic modulus of concrete with level as claimed in claim 1, characterized in that, there are two positioning plates (6).