JP2013011575A - Portable concrete compression testing machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem that, since a conventional portable compression testing machine is structured to hold load mounting means by two reaction columns set up in a portal shape, transportation is not facilitated due to heavy weight and a modulus of static elasticity of a concrete specimen could not be measured.SOLUTION: A portable concrete compression testing machine comprises: load mounting means (electrically-driven hydraulic pump) A; load detecting and displaying means (strain gauge: load cell) B; and specimen holding means C constituted by arranging in series the load mounting means A and the load detecting and displaying means B in a vertical center axis within a cylindrical machine frame. The testing machine reduces its weight and size, facilitates its transportation to a narrow place and can also measure a modulus of static elasticity of a specimen.

Description

  The present invention relates to a portable concrete compression test apparatus that can easily measure the compressive strength and static elastic modulus of all sampled concrete specimens on site.

  There is a conventional concrete portable compression tester in which the upper and lower reaction force frames are fixed by two right and left columns, and the pressure member supported by the reaction force columns is operated by a manual hydraulic device. . (For example, refer nonpatent literature 1.)

  Moreover, it displays with the Bourdon tube type pressure gauge of each of a high load and a low load as a load display means of the pressure which acts on a concrete specimen. (See Non-Patent Document 1 above.)

Next, the conventional example will be described in more detail with reference to FIG.
The concrete specimen a is pressed by the manual hydraulic device e between the two left and right reaction force columns b, b ′ supported by the lower base f and the upper reaction member g at the upper ends of the reaction force columns b, b ′. In addition, the Bourdon tube pressure gauges c and c ′ are installed so that either high load or low load can be switched and displayed.

  The portable compression tester is roughly divided into six parts: a lower pedestal f, an upper reaction force member g, two left and right reaction force columns b and b ', a manual hydraulic device e, and a pressure plate d. Although it can be divided, the total weight is about 400 kg.

  Portable compression tester SS-C-544-545 (Shinohara Works: Catalog)

The concrete portable compression tester shown in the above conventional example has a total weight of about 400 (kg), and such heavy objects are carried into a confined place, a construction site in an arbitrary urban area, or a mountainous area. That was not easy.
Moreover, even if such a bulky portable compression tester is brought to the site, it must be disassembled and transported into 6 parts for transport, and since it is heavy, a foundation for installation is required. It is necessary, and it is necessary to assemble again on the site after the transfer, and such work requires a lot of manpower and labor.

  In addition, since the compression tester manually operates the hydraulic device during the pressurizing operation, it cannot apply a load to the concrete specimen at a constant speed, and the static elasticity of the concrete specimen required by JIS A 1149. It is impossible to measure the coefficient.

  Furthermore, the load is measured with a Bourdon tube pressure gauge. For the maximum load of 1000 (kN), the Bourdon tube pressure gauge for high load is 4 (kN), and the Bourdon tube pressure gauge for low load is used. However, only 1 (kN) measurement resolution is maintained.

In addition, the installation space of the conventional example is about 3000 (cm ² ) including the most protruding part, and taking into consideration the work space, it is not easy to bring it into a narrow place.

  In the present invention, although the maximum load is 1000 (kN) and high load, the two reaction force struts are not used, the load loading means (electric hydraulic pump) A and the load detection display means (strain gauge: A load cell) B, the load loading means A and the load detection display means B are arranged in series with a specimen holding means C on a single vertical center axis in a cylindrical machine frame (φ200 × 800 (mm)). -Not only can it be reduced in size and easily carried into confined spaces, but it can also measure the static elastic modulus of concrete specimens.

  In the present invention, the two reaction force struts required in the conventional example can be obtained by arranging the load loading means, the load detection display means, and the test body in which the test apparatus main body is cylindrical as described above in series. This eliminates the need for lighter and smaller testing equipment. As a result, it can be carried into confined spaces, construction sites in arbitrary cities, or mountainous areas, and has various strengths sampled from concrete structures at the site. A compression test of a concrete specimen can be performed on the spot.

  In the present invention, when pressure is loaded on the specimen, the load acting means, the load detection display means, the specimen, etc. are arranged in series on one action line of pressure, so that the stress acting on the specimen is not dispersed. The load can be loaded on the specimen effectively.

  Furthermore, since the pressurizing unit is driven by an electric hydraulic pump, there is no deterioration in the left / right load balance as in the case of a conventional manual hydraulic device, the load loading speed is stable, the maximum compressive load is measured, and concrete is supplied. The static elastic modulus of the specimen can also be measured with high accuracy.

  Since the load is measured with a load cell, it has a measurement resolution of 0.1 (kN) for a maximum load of 1000 (kN), compared to the conventional Bourdon tube pressure gauge. It retains 10 to 40 times the resolution and enables accurate compression testing.

The pedestal 1 of the test apparatus has an installation space of 1600 (cm ² ) with 40 (cm) and 40 (cm), which is about half the area of the conventional example and can be brought into a narrow place.

  Longitudinal cross-sectional front view of the main part of the device of the present invention   Front view of conventional example

Hereinafter, an embodiment of the present invention will be described with reference to FIG.
In the figure, the present invention is roughly divided into a load loading means A, a load detection display means B, and a specimen holding means C.
First, the load loading means A fixes a lower portion of a reaction force outer cylinder 2 having a dimension φ200 × 800 (mm) having sufficient resistance to the load on the pedestal 1, and a pressure cylinder in the reaction force outer cylinder 2. (Spring return cylinder) 3 is water-tightly fitted and is configured to move up and down in response to oil pressure from a separately installed electric hydraulic pump 11.

  In addition, the load detection display means B is placed at a position above the pressure cylinder 3 with a constant gap between the load cylinder 4 and the inner circumference of the reaction force outer cylinder 2, and the detected value from the load cell 4 is detected. Is electrically guided to the data logger 12 for calculation display.

  The specimen holding means C interposes the specimen 13 between the pressure plate 5 and the pressure bearing plate 6 with the ball seat in the reaction force outer cylinder 2 and via the sphere 7 at the center of the upper surface of the pressure plate 6 with the ball seat. Thus, it is screwed by a setting screw lid 8 at the upper end of the reaction force outer cylinder 2. Reference numeral 10 denotes a handle of the setting screw lid 8.

In addition, the said compression test apparatus is attached on the base 1 of 40 (cm) * 40 (cm), a loading apparatus main body is about 60 (kg), and a total weight is about 80 (kg).
Further, the pressure plate 5 placed on the load cell 4 is engraved with a diameter of 100 (mm) on the upper surface, and the specimen 13 having a diameter of 100 (mm) and a length of 200 (mm) is attached to the pressure plate 5. The center position is correctly held.
In addition, there are pressure plates of a size different from the above, and a surface with a score of 80 (mm) on the top surface is added. This can be applied to a specimen having a diameter of 80 (mm) and a length of 160 (mm). A platen is also available.

  Next, a series of operations will be described. The specimen 13 is installed according to the size of the positioning markings having a diameter of 100 (mm) or 80 (mm) applied to the pressure plate 5 on the load cell 4, and the specimen is tested. The setting of the specimen 13 is completed by screwing the ball bearing pressure board 6 onto the reaction force outer cylinder 2 via the ball 7 on the ball seat pressure board 6 placed on the upper end of the ball 13. In this state, the strain value is taken out from the load cell 4 through the slit 9 formed on the side surface of the reaction force outer cylinder 2 by the lead wire and input to the data logger 12.

  The electric hydraulic pump 11 controls the start, stop, and flow rate adjusting valve with a remote switch to adjust the pressurization speed, and can easily measure distortion at one third of the maximum expected load. Therefore, the static elastic modulus of the specimen 13 is obtained. The load loading method with respect to the specimen 13 is a simple configuration including only the pressure plate 6 with a ball seat, the pressure cylinder 3 and the load cell 4 for load measurement, which are screwed onto the upper end of the reaction force outer cylinder 2. There is no such a support and it can be made compact.

  Securely screw the setting screw lid 8 to the reaction tube 2 and connect the output cable of the load cell 4 and the strain gauge lead attached to the specimen 13 to a commercially available data logger 12, etc. Keep it.

  The switch of the electric hydraulic pump 11 is turned on to start loading and distortion measurement, and at the same time the specimen 13 is destroyed, the loading operation is automatically terminated.

  Since the present invention is portable, it can be used not only for the concrete compression test but also for all the above-mentioned places, as well as for the compression test of rocks and the like, and is a highly versatile device.

DESCRIPTION OF SYMBOLS 1 Base 2 Reaction force outer cylinder 3 Pressurizing cylinder 4 Load cell 5 Lower pressure-resistant board 6 Pressure-resistant board 7 with a ball seat 7 Sphere 8 Setting screw lid 9 Slit 10 Setting handle 11 Electric hydraulic pump 12 Data logger 13 Specimen A Load loading means B Load detection display means C Specimen holding means

Claims (2)

A compressive force can be applied to a specimen having a pedestal, a reaction force support member, a lower pressure plate, a pressure plate with a ball seat, a pressure cylinder, a sphere, an upper reaction force member, and a hydraulic pump. A device,
The reaction force support member is a cylindrical reaction force outer cylinder, the lower part is fixed to the pedestal, and has a proof stress exceeding a maximum load of 1000 (kN),
The upper reaction force member is a screw lid, screwed to the upper end of the reaction force outer cylinder,
The pressure cylinder, the lower pressure plate, the ball seat additional pressure plate, and the sphere are installed in the reaction force outer cylinder,
The sphere is installed in the center of the upper surface of the pressure plate with the ball seat and at the lower part of the screw lid, and a specimen is interposed between the lower pressure plate and the pressure plate with the ball seat, and the naked lid is An apparatus capable of being held via the sphere by screwing on a reaction force outer cylinder. The hydraulic pump can automatically load at a constant speed,
The detected value of the load cell placed between the pressurizing cylinder and the specimen and the detected value of the strain gauge attached to the specimen are electrically transferred to the data logger outside the reaction force outer cylinder. Can lead and
The apparatus according to claim 1, wherein a static elastic modulus of the specimen can be obtained from a detection value of the load cell and a detection value of the strain gauge.

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