RU1778675C - Device for determining strength of concrete - Google Patents

Abstract

The invention relates to a technique for non-destructive testing of concrete quality and can be used to evaluate the strength of concrete, for example, in operating reinforced concrete structures. The purpose of the invention is to increase the accuracy and productivity of concrete strength control. A device for monitoring the strength of concrete comprises an indenter, a hammer, a percussion mechanism and an indicator. New in the device is the introduction of an indenter made of detachable two parts, between which an electro-acoustic transducer is coaxially mounted, an amplifier in series, a signal envelope driver, a key, an analog-to-digital converter and an indicator, as well as a time interval driver, the input of which is connected to the output of the driver the envelope of the signal, and the output to the control input of the key, the input of the amplifier is connected to the electro-acoustic transducer. The striker with the indenter strikes the controlled item without rebounding. 1 silt. Joint venture with 6

Description

The invention relates to a technique for non-destructive testing of concrete quality and can be used to evaluate the strength of concrete, for example, in operating reinforced concrete structures.

Devices are known for determining the strength of concrete by non-destructive methods or with partial destruction, based on the use of the correlation dependence of some physical characteristics with the strength of concrete.

Such devices include, for example, a Kashkarov hammer, when using which the strength is determined by the diameter of the print, a tear-off device based on measuring the force that

needed to tear concrete layer 1 away from the surface of the product.

A disadvantage of the known devices is the low accuracy and control performance associated with the need to manually calculate the strength of concrete from the measurement data.

The closest to the claimed device in technical essence and the achieved result is a device for determining the strength of concrete selected as a prototype, based on measuring the rebound of an elastic rod after hitting it on a concrete surface (Schmidt sclerometer), containing a striker, indenter, shock spring and indicator 2.

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A disadvantage of the known device is the low accuracy and control performance. This is due to the fact that the friction force in the moving parts, the magnitude of the preliminary pressure of the tip on the test material, and the location of the device relative to the test material have an influence on the measurement accuracy. A known device cannot be used for mass automatic control of standard products and structures.

The purpose of the invention is to increase the accuracy and productivity of concrete strength control.

The goal is achieved in that in a device containing coaxially mounted firing pin, impact mechanism and indicator, a series-connected electro-acoustic transducer, amplifier, signal envelope shaper, switch and analog-to-digital converter, the output of which is connected to the indicator input, and a time interval shaper, input, are introduced which is connected to the output of the envelope of the signal envelope, the output is to the control input of the key, and the indenter is made detachable from two parts, between which the electric kustichesky converter.

The drawing shows a block diagram of a device for measuring strength.

The device for determining the strength of concrete contains coaxially mounted striker 1, indenter 2, percussion mechanism 3 and indicator 4, serially connected electro-acoustic transducer 5, amplifier 6, signal envelope shaper 7, key 8 and analog-to-digital converter 9, the output of which is connected to the indicator input 4, and the shaper 10 of the time interval, the input of which is connected to the output of the shaper 7 of the envelope of the signal, and the output to the control input of the key 8, the indenter 2 is made detachable from two parts, between which the electro-acoustic transducer 5 is clearly installed, Position 11 in the drawing shows a controlled product.

A device for determining the strength of concrete works as follows.

The firing pin 1 with indenter 2, in which the electro-acoustic transducer 5 is installed, is hit by the action of the impact mechanism 3 on the surface of the material being monitored 11 without rebound.

Under the influence of shock, the electro-acoustic transducer 5 generates an electrical signal, the magnitude of which depends on the ratio of the elastic moduli

electro-acoustic transducer 5 and controlled material 11. In turn, the elastic modulus of the controlled material depends on its strength characteristics. Electrical signal with

electro-acoustic transducer 5, the magnitude and duration of which depends on the strength of the material being monitored, is fed to amplifier 6 and then to the envelope shaper of signal 7. From the shaper of the envelope, the signal goes to key 8 and to shaper 10 of the time interval, which generates a time interval, the value of which depends from the nature of the envelope of the signal generated by the electro-acoustic transducer 5 and the shaper 7 of the envelope of the signal.

Shaper 10 time interval controls the key 8. From the output of the key 8

an electric signal is supplied to an analog-to-digital converter 9 and then the converted signal is displayed by indicator 45 in units of strength.

The use of a device for determining the strength of concrete in comparison with existing devices provides higher accuracy and reliability of quality control and can be used in automated stands for mass automatic control of standard products and structures.

Claims (1)

The claims A device for determining the strength of concrete, comprising coaxially mounted strikers, an indenter, a percussion mechanism and an indicator, characterized in that, in order to increase the accuracy of the control of strength concrete, it is equipped with a series-connected electro-acoustic transducer, amplifier, signal envelope shaper, a key and an analog-to-digital converter, the output of which it is connected to the indicator input and a time interval shaper, the input of which is connected to the output of the envelope of the signal envelope, the output is to the control input of the key, and the indenter is made detachable from two parts, between which the electro-acoustic transducer is coaxially mounted.