CN103760327A - Concrete shrinkage measuring instrument - Google Patents

Abstract

The invention discloses a concrete shrinkage measuring instrument, comprising an inclined platform base, the angle between the inclined surface of the inclined platform base and the bottom surface is 3°-10°; two end plates are symmetrically arranged on the inclined surface of the inclined platform base, The end plate is perpendicular to the slope of the inclined platform of the base; a micrometer is arranged on the high end plate of the inclined surface of the base of the inclined platform, and a positioning column is arranged on the low end plate of the inclined surface of the base of the inclined platform. The micrometer is corresponding to the position of the positioning column; the inclined surface of the inclined platform base is also provided with a plurality of concrete support frames between the two end plates, and the top of the concrete support frame is provided with a rolling shaft. The slope of the base of the inclined platform is parallel to and perpendicular to the connecting line between the micrometer and the positioning column. The concrete test block is placed at a small angle, so that the concrete test block has a small sliding force, so that the test block is always in close contact with the dial gauge and the positioning column, with high measurement accuracy, simple structure, low cost and easy operation.

Description

A concrete shrinkage measuring instrument

technical field

The invention relates to a measuring instrument, in particular to a concrete shrinkage measuring instrument.

Background technique

Concrete is a very important civil engineering material and is widely used in civil engineering. Concrete shrinkage is the shrinkage of the volume that occurs in the early stage of concrete setting or during the hardening process. Concrete shrinkage can cause damage such as cracking of components and loss of pre-tightening force. In order to prevent the harm caused by concrete shrinkage, it is necessary to measure the shrinkage rate of the concrete in accordance with the provisions of GB/T50082-2009 during the concrete development process. Concrete shrinkage is measured by a special tool called a concrete shrinkage measuring instrument, and the shrinkage is obtained through multiple measurements of concrete specimens by a concrete shrinkage instrument.

At present, there are two kinds of concrete shrinkage measuring instruments on the market: non-contact type and contact type. Insufficient contact between the concrete test block and air, frequent manual operation and other factors that will cause obvious errors, or use two dial gauges to measure, due to the error of the dial gauge itself or the error caused by manual reading, use two dial gauges The sub-meter measurement increases the error, resulting in poor accuracy of the measurement results.

Contents of the invention

In order to solve the above problems, the present invention provides a concrete shrinkage measuring instrument with simple structure, high measurement accuracy, convenient use and low cost.

The present invention adopts the following technical solutions: a concrete shrinkage measuring instrument, comprising an inclined platform base, the angle between the inclined surface of the inclined platform base and the bottom surface is 3°-10°; the inclined surface of the inclined platform base is symmetrically provided with two An end plate, the end plate is perpendicular to the slope of the inclined platform of the base; the end plate located at the high position of the inclined surface of the base of the inclined platform is provided with a micrometer, and the front end of the measuring shaft of the micrometer is concave to match the shrinkage of the concrete The measuring head on the test block is used for positioning measurement; the end plate located at the lower end of the inclined plane of the base of the inclined platform is provided with a positioning column, and the front end of the positioning column is in a concave shape to match the measuring head on the concrete shrinkage test block. Perform positioning measurement; the micrometer corresponds to the position of the positioning column; the inclined surface of the inclined platform base is located between the two end plates and a plurality of concrete support frames are provided, and the top of the concrete support frame is provided with a rolling shaft, used to support the concrete test block, the rolling shaft is parallel to the slope of the inclined platform base and perpendicular to the connection line between the micrometer and the positioning column, so as to reduce the distance between the concrete test block and the rolling shaft of friction.

Preferably, the angle between the slope of the base of the inclined platform and the bottom surface is 5°; the friction coefficient μ of the rolling shaft is generally about 0.01, when the concrete test block is placed on the rolling shaft, the gravity of the concrete test block must The component force along the slope direction of the inclined platform base is greater than its frictional force, and the component force should be as small as possible so as not to affect the accuracy of measurement, i.e. mg "sin α > μ mg" cos α, and α is as small as possible Value, after calculation, 5° is the optimal value.

Preferably, the height of the concrete support frame is greater than 3 cm, which can make the concrete test block more fully contact with the air and ensure the accuracy of the test.

Preferably, both the micrometer and the positioning column are located on the longitudinal centerline of the end plate, which can make the whole tester more regular and more beautiful.

Preferably, the micrometer is an electronic micrometer, and the electronic micrometer is electrically connected to a solar photovoltaic panel to ensure the power supply of the electronic micrometer during a long test period.

Compared with the prior art, the present invention has the following beneficial effects: the concrete test block is placed at a small angle, so that the concrete test block has a small sliding force, and the test block is always in close contact with the dial indicator and the positioning column , and because the angle is very small, it will not be affected by the gravity of the concrete test block itself; at the same time, the concrete test block can be fully contacted with the air, and a dial gauge is used for measurement, which is less affected by instrument errors, high measurement accuracy, and the structure Simple, low cost and easy to operate.

Description of drawings

Fig. 1 is a perspective view of the present invention;

Fig. 2 is the front view of the present invention;

Fig. 3 is the top view of the present invention;

Among them: 1. Inclined platform base, 2. End plate, 3. Electronic micrometer, 4. Solar photovoltaic panel, 5. Positioning column, 6. Concrete support frame, 7. Rolling shaft.

Detailed ways

The present invention is described by examples below, and it should be noted that the examples listed should not be construed as limiting the invention.

As shown in the figure: a concrete shrinkage measuring instrument, including an inclined platform base 1, two end plates 2 are symmetrically arranged on the inclined surface of the inclined platform base 1, and the inclined surface of the inclined platform 1 of the base and the end plate 2 Vertical; the end plate 2 located at the high position of the inclined plane of the inclined platform base 1 is provided with an electronic micrometer 3, and the front end of the measuring shaft of the electronic micrometer 3 is in a concave shape to cooperate with the measuring head on the concrete shrinkage test block to carry out For positioning measurement, the electronic micrometer 3 is electrically connected to a solar photovoltaic panel 4 to ensure the power supply of the electronic micrometer 3 during a long test period; it is located on the end plate 2 at the lower end of the inclined plane of the inclined platform base 1 A positioning column 5 is provided, and the front end of the positioning column 5 is in a concave shape, so as to cooperate with the measuring head on the concrete shrinkage test block for positioning measurement; the electronic micrometer 3 corresponds to the position of the positioning column 5; The slope of the inclined platform base 1 is also provided with four concrete support frames 6 between the two end plates 2, the height of the concrete support frames 6 is greater than 3cm, which can make the contact between the concrete test block and the air more sufficient and ensure The accuracy of the test; the top of the concrete support frame 6 is provided with a rolling shaft 7 for supporting the concrete test block, the rolling shaft 7 is parallel to the slope of the inclined platform base 1 and is parallel to the electronic micrometer 3 and the The line connecting the positioning columns 5 is vertical to reduce the friction between the concrete test block and the rolling shaft 7 .

The angle between the slope and the bottom surface of the inclined platform base 1 is 5°; the friction coefficient of the rolling shaft is generally about 0.01. When the concrete test block is placed on the rolling shaft 7, the gravity of the concrete test block must The component force in the slope direction of the inclined platform base 1 is greater than its friction force, and the component force should be as small as possible so as not to affect the accuracy of the measurement, that is, mg″sinα>μmg″cosα, and α should be as small as possible , after calculation, 5° is the optimal value.

Both the micrometer and the positioning column are located on the longitudinal centerline of the end plate, which can make the whole tester more regular and more beautiful.

Apparently, the above content is only to illustrate the characteristics of the present invention, but not to limit the invention. Changes made by persons of ordinary skill in the relevant technical field in the corresponding technical field according to the present invention shall belong to the protection scope of the present invention.

Claims (5)

1. A concrete shrinkage measuring instrument is characterized in that it comprises an inclined platform base, and the angle between the slope of the inclined platform base and the bottom surface is 3 °-10 °; the inclined surface of the inclined platform base is symmetrically provided with two An end plate, the end plate is perpendicular to the slope of the inclined platform of the base; a micrometer is arranged on the end plate at the high position of the inclined surface of the base of the inclined platform, and the front end of the measuring shaft of the micrometer is concave; The lower end plate of the slope of the base is provided with a positioning column, and the front end of the positioning column is concave; the position of the micrometer corresponds to the position of the positioning column; A plurality of concrete support frames are also arranged between, and a rolling shaft is provided on the top of the concrete support frame, and the rolling shaft is parallel to the slope of the inclined platform base and perpendicular to the line connecting the micrometer and the positioning column. 2. The concrete shrinkage measuring instrument according to claim 1, wherein the angle between the slope of the base of the inclined platform and the bottom surface is 5°. 3. The concrete shrinkage measuring instrument according to claim 1, characterized in that, the height of the concrete support frame is greater than 3cm. 4. The concrete shrinkage measuring instrument according to claim 1, characterized in that, both the micrometer and the positioning column are located on the longitudinal centerline of the end plate. 5. The concrete shrinkage measuring instrument according to claim 1, wherein the micrometer is an electronic micrometer, and the electronic micrometer is electrically connected to a solar photovoltaic panel.

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