CN211576069U - An Improved Contact Concrete Expansion and Shrinkage Tester - Google Patents

Abstract

The utility model relates to the technical field of concrete deformation measuring equipment, in particular to an improved contact type concrete expansion and contraction instrument, comprising a base, two sides of the base are respectively provided with a support part and a reference plate, and a measuring device is installed on the support part , the reference plate is provided with a guide chute, a positioning plate is arranged between the support part and the reference plate, a positioning groove is opened on the axis of the positioning plate, and the positioning groove is connected to the measuring device and the guide chute. In the same vertical plane, when carrying out the concrete expansion test, the staff only needs to insert the pre-embedded probes on both sides of the concrete sample into the positioning grooves on the positioning plate, so as to ensure that the probes on both sides of the concrete sample are consistent with each other. The measuring device and the guide chute are in the same vertical plane, so that the axis of the concrete sample will not be offset, avoiding the measurement error of the expansion or shrinkage measurement value of the concrete sample caused by human factors, and ensuring the accuracy of the experiment.

Description

An Improved Contact Concrete Expansion and Shrinkage Tester

technical field

The utility model relates to the technical field of concrete deformation measuring equipment, in particular to an improved contact type concrete expansion and contraction instrument.

Background technique

Concrete expansion and contraction tester is a special instrument used to measure the change in length or volume of concrete specimens during the hardening process under certain environmental conditions. Concrete will expand and shrink during curing or when encountering changes in natural environment. Expansion and contraction of concrete can cause cracks in the wall, affecting the durability of the concrete structure.

The existing concrete expansion and contraction tester includes a base, a backing plate and a dial indicator bracket symmetrically arranged at both ends of the base. During the concrete expansion test, the concrete sample is placed between the dial indicator bracket and the backing plate to make the concrete The probes embedded on both sides of the sample are in conflict with the dial gauge and the backing plate respectively, and then the expansion and shrinkage change values caused by the concrete curing period or environmental temperature changes are obtained through the reading of the dial gauge. The concrete sample is in the expansion and contraction test. The measurement accuracy of shrinkage or expansion value is only 0.001mm.

The prior art scheme in the above has the following defects: because the concrete sample is manually placed on the base by the staff, it cannot be guaranteed that the measuring heads on both sides of the concrete sample, the dial indicator and the backing plate are in the same vertical plane, which causes Due to the high test accuracy of the dial indicator, even a small offset will affect the accuracy of the experiment.

Utility model content

In view of the deficiencies in the prior art, the purpose of the present invention is to provide an improved contact type concrete expansion and contraction meter to solve the above problems.

An improved contact-type concrete expansion-contraction instrument comprises a base, a support part and a reference plate are respectively provided on both sides of the base, a measuring device is installed on the support part, and a guide chute is arranged on the reference plate, so the A positioning plate is arranged between the support portion and the reference plate, a positioning groove is formed on the axis of the positioning plate, and the positioning groove, the measuring device and the guide chute are in the same vertical plane.

Preferably, the positioning groove is a U-shaped groove with an upper opening, and a measuring head is pre-buried on both sides of the concrete sample to be tested. connected, the probe on the other side is in contact with the guide chute.

Preferably, the support part includes a support plate, the support plate is provided with a high-adjustment hole for adjusting the height of the measuring device, a thread groove is opened on one side of the high-adjustment hole, and a threaded groove is rotatably connected in the thread groove for fixing Locking part of the measuring device.

Preferably, the base is provided with a slideway, the bottom of the positioning plate is provided with a slider, and the positioning plate is slidably engaged with the base.

Preferably, the base is also provided with a calibration mechanism.

Preferably, the calibration mechanism includes a vertical plate and a standard rod, the vertical plate is placed between the support plate and the reference plate, the standard rod penetrates the vertical plate, one side of the standard rod is in contact with the measuring device, and the other side is in contact with the measuring device. the chute on the reference plate.

Preferably, the measuring device is a dial indicator or a micrometer with an accuracy of 0.001 mm, and the standard rod is made of hard steel or quartz glass.

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

The equipment of the utility model is provided with a positioning plate on the base, a positioning groove is formed on the axis of the positioning plate, and the positioning groove is in the same vertical plane as the measuring device on the support plate and the guide chute on the reference plate; During the expansion test, the staff only needs to insert the probes embedded on both sides of the concrete sample into the positioning grooves on the positioning plate to ensure that the probes on both sides of the concrete sample are in the same vertical position as the measuring device and the guide chute. In-plane, the concrete sample will not be offset, avoid the expansion or shrinkage of the concrete sample caused by human factors, and ensure the accuracy of the experiment.

Description of drawings

FIG. 1 is a schematic structural diagram of an improved contact-type concrete expansion-contraction meter in this embodiment.

FIG. 2 is a side view of an improved contact-type concrete expansion-contraction meter in this embodiment.

FIG. 3 is a top view of an improved contact-type concrete expansion-contraction meter in this embodiment.

Figure 4 is a schematic diagram of the structure of the concrete test sample.

In the attached drawings: 1 base, 1-1 slide, 2 support plate, 2-1 measuring device, 2-2 high adjustment hole, 3 reference plate, 3-1 guide chute, 4 positioning plate, 4-1 positioning groove , 5 vertical plates, 6 standard bars, a pre-embedded probe, b post-embedded probe c concrete test sample.

Detailed ways

The technical solutions in the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the implementations. example. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present invention.

It should be noted that when a component is referred to as being "mounted on" another component, it can be directly on the other component or there may also be an intervening component. When a component is considered to be "connected" to another component, it may be directly connected to the other component or there may be a co-existence of an intervening component. When a component is considered to be "set" another component, it may be located directly on the other component or may co-exist with a centered component. The terms "center," "inner," "left," "right," and similar expressions are used herein for illustrative purposes only.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the technical field to which the present invention belongs. The terms used in the description of the present invention herein are only for the purpose of describing specific embodiments, and are not intended to limit the present invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

Please refer to FIG. 1 to FIG. 4 at the same time, an improved contact-type concrete expansion-contraction meter includes a base 1, a support portion and a reference plate 3 are respectively provided on both sides of the base 1, and a measuring device 2 is installed on the support portion. -1, the reference plate 3 is provided with a guide chute 3-1, a positioning plate 4 is arranged between the support portion and the reference plate 3, and a positioning groove 4-1 is opened on the axis of the positioning plate 4 , the positioning groove 4-1 is in the same vertical plane as the measuring device 2-1 and the guide chute 3-1, the positioning plate 4 is provided with two pieces, one is installed inside the support part, and the other is installed on the reference Inside of plate 3.

When placing the concrete sample, the staff first picks up the concrete sample, aligns the probes on both sides with the positioning grooves on the two positioning plates, and then slowly puts the concrete sample in the direction of the positioning groove. When the probe on one side of the sample touches the guide chute 3-1 on the reference plate 3, and the probe on the other side touches the measuring device 2-1, the placement of the concrete sample is completed.

The positioning groove 4-1 is a U-shaped groove with an upper opening, and a measuring head is pre-buried on both sides of the concrete sample to be tested. -1 is connected, and the probe on the other side is in contact with the guide chute 3-1.

Since the concrete samples to be tested may have different heights each time, the heights of the probes pre-buried on both sides of the concrete samples will also change. Therefore, in this embodiment, the positioning groove 4-1 adopts an upper opening. U-shaped groove, so that when the height of the concrete sample changes, the probes on both sides can still be placed in the positioning groove 4-1.

The support part includes a support plate 2, and the support plate 2 is provided with a height adjustment hole 2-2 for adjusting the height of the measuring device 2-1, and a thread groove is opened on one side of the height adjustment hole 2-2. A locking piece for fixing the measuring device 2-1 is rotatably connected in the threaded groove, and the locking piece is a star-shaped handle screw.

Since the concrete samples to be tested may have different heights each time, the height of the measuring device 2-1 also needs to be changed. 2-1 Take out from the height adjustment hole 2-2, and then put it into the height adjustment hole with the same height as the concrete sample to be tested, and then tighten the star handle screw to complete the height adjustment of the measuring device 2-1.

The base 1 is provided with a slideway 1-1, the bottom of the positioning plate 4 is provided with a slider 4-2, and the positioning plate 4 is slidably engaged with the base 1.

The sliding block 4-2 adopts a T-shaped sliding block, and the sliding path 1-1 adopts a sliding path matching the T-shaped sliding block. The design is stable in structure, easy to disassemble, and can easily replace the damaged positioning plate. In addition, when not in use, it can be disassembled to save space.

The base 1 is also provided with a calibration mechanism, the calibration mechanism includes a vertical plate 5 and a standard rod 6, the vertical plate 5 is placed between the support plate 2 and the reference plate 3, and the standard rod 6 penetrates the vertical plate 5, One side thereof is against the measuring device 2-1, and the other side is against the chute 3-1 on the reference plate 3.

Before the expansion and contraction measurement, the zero point of the measuring device 2-1 should be calibrated with the standard rod 6, and should be re-checked at least 1-2 times during the measurement process, one of which should be carried out after all the test pieces are read. When the deviation between the zero point and the original value is found to exceed ±0.001mm during the review, it should be re-measured after zero adjustment;

For the detailed usage of the standard bar 6 and the vertical plate 5, please refer to the "Standard for the Long-term Performance and Durability of Ordinary Concrete" (GBT50082-2009).

The measuring device 2-1 is a dial indicator or a micrometer with an accuracy of ±0.001 mm, and the standard rod 6 is made of hard steel or quartz glass.

working principle:

Before the test, carry out the elevation according to the set height of the concrete specimen; during the elevation, the height of the vertical plate 5 should be the same as the height of the concrete specimen. 2009), and then adjust the height of the dial indicator 2-1 according to the position of the vertical plate 5 and the standard rod 6, take out the dial indicator 2-1 from the original high-adjustment hole, and put it in the same height as the standard rod 6 and fix it with the star-shaped handle screw. After the height adjustment is completed, remove the vertical plate 5 and the standard rod 6;

During the test, the concrete sample to be tested by the staff is placed between two positioning plates. The measuring head penetrates the positioning groove on the other positioning plate and interferes with the guiding chute 3-1 on the reference plate 3; it can ensure the measuring head on both sides of the concrete sample, the dial indicator 2-1, and the guiding chute 3 -1 on the same axis, so that the axis of the concrete sample will not be offset.

Claims (7)

1. An improved contact type concrete expansion-contraction instrument is characterized in that: comprise a base (1), and both sides of the base (1) are respectively provided with a support portion and a reference plate (3), and the support portion is provided with A measuring device (2-1), the reference plate (3) is provided with a guide chute (3-1), and a positioning plate (4) is arranged between the support part and the reference plate (3), the positioning A positioning groove (4-1) is provided on the axis of the plate (4), and the positioning groove (4-1) is in the same vertical plane as the measuring device (2-1) and the guide chute (3-1). . 2. An improved contact-type concrete expansion-contraction meter according to claim 1, characterized in that: the positioning groove (4-1) is a U-shaped groove with an upper opening, and both sides of the concrete sample to be detected are previously A probe is embedded, the probe is clamped in the U-shaped groove, one side of the probe is connected to the measuring device (2-1), and the other side of the probe is in contact with the guide chute (3-1) . 3. An improved contact-type concrete expansion-contraction meter according to claim 1, characterized in that: the support part comprises a support plate (2), and the support plate (2) is provided with a measuring device ( 2-1) A height adjustment hole (2-2), a thread groove is formed on one side of the height adjustment hole (2-2), and a thread for fixing the measuring device (2-1) is rotatably connected in the thread groove. locking piece. 4. An improved contact-type concrete expansion-contraction meter according to claim 1, characterized in that: a slideway (1-1) is provided on the base (1), and a bottom of the positioning plate (4) is provided with a slideway (1-1). A slider (4-2) is provided, and the positioning plate (4) is slidably and clamped with the base (1). 5. An improved contact-type concrete expansion-contraction meter according to claim 3, characterized in that: the base (1) is further provided with a calibration mechanism. 6. An improved contact-type concrete expansion-contraction meter according to claim 5, characterized in that: the calibration mechanism comprises a vertical plate (5) and a standard rod (6), and the vertical plate (5) is placed on the Between the support plate (2) and the reference plate (3), the standard rod (6) penetrates the vertical plate (5), one side of the standard rod (6) is in contact with the measuring device (2-1), and the other side is in contact with the reference plate (3) on the chute (3-1). 7. An improved contact-type concrete expansion-contraction meter according to claim 6, characterized in that: the measuring device (2-1) adopts a dial indicator or a micrometer with an accuracy of 0.001 mm, and the standard The rod (6) is made of hard steel or quartz glass.

Images