SU1114945A1 - Device for determination of concrete strength - Google Patents

Abstract

A DEVICE FOR DETERMINING THE STRENGTH OF CONCRETE, containing a series-connected clock generator, a control interval shaping unit, an ultrasonic oscillator, emitting an electro-acoustic transducer, a receiving electro-acoustic transducer, an amplifier, a measured time interval former, a time discriminator s 5 5 i J W .; i: and the generator of counting pulses, the output of which is connected to the second input of the control unit for forming a low, terval time, the output of the last with Connected to the second inputs of the time discriminator and the generator of the measured time interval, the serially connected generator of the calibration time interval, the selector, the second input of which is connected to the output of the counting pulse generator, and a counter, characterized in that it is equipped with connected to the output of the counter by series-connected zero indication circuit, (L three-input circuit AND, the second input of which is connected to the output of the counting pulse generator, and t ety input to the second output generator calibration time interval, and the block numbers in erecting chetverTjno extent made reversible counter and a second input connected to the output circuit trehvhodovoy VI; about sd

Description

 one

This invention relates to a technique for non-destructive testing of materials and products using ultrasound and can be used to control the quality of concrete.

A device is known for determining the strength of a concrete, which contains a series-connected clock generator, a control interval formation unit, an ultrasonic vibration generator, an emitting electroacoustic converter, a receiving electroacoustic converter, an amplifier, a measured time interval generator, a time discriminator, and a counting pulse generator, the output of which is connected to the second input of the control interval formation block, the output of the last connection n; with the second inputs of the time discriminator and the former of the measured time interval, the serially connected generator of the calibration time interval, the selector, the second input of which is connected to the output of the counting pulse generator, and the counter t.

Using a known device, the ultrasound velocity in a sample of concrete is measured. The strength of concrete can be determined by calculation by the formula

R gv (1)

where g is the empirical coefficient; V is the ultrasound velocity in the sample.

A disadvantage of the known device is its limited functionality — the device does not allow to determine directly the value of concrete strength.

     , :

The purpose of the invention is to expand the functional possibilities.

This goal is achieved by the fact that a device for determining the strength of concrete, containing sequentially connected generator of sync pulses, a unit for forming a control interval of time, an ultrasonic vibration generator, an emitting electroacus transducer, a received electroacoustic transducer, amplifier, driver

149452

. the measured time interval, the time discriminator and the generator of counting pulses, the output of which is connected to the second input of the force block of the control time interval, the output of the latter is connected to the second inputs of the time discriminator and the former of the measured time interval, sequentially. (0 Tightly connected generator of the calibration time interval , selector, the second input of which is connected to the output of the generator of counting pulses, and the counter, is connected in series with the output of the counter in series The zero display circuit, the three-input circuit I, the second input of which is connected to the output of the counting impulses generator Q2, and the third input to the second output of the calibration time generator, and the fourth-power raising unit, the counter is reversible, and

5 bgo the second input is connected to the output of the three-input circuit I.

The drawing shows a block diagram of a device for determining the strength of concrete.

The device contains a series-connected sync pulse generator 1, a control time interval forming unit 2, an ultrasonic oscillator 3 oscillator 5, an electroacoustic transducer 4 emitting, a transceiver electroacoustic transducer 5, an amplifier 6, a driver 7 of the measured time interval,

0 time discriminator 8 and the generator 9 of counting pulses, the output of which is connected to the second input of the control time interval formation unit 2, the output of the latter is connected to the second inputs of the time discriminator 8 and the former 7 of the measured time interval, sequentially connected the generator 10 of the calibration time interval, the selector 11, the second input of which is connected to the output of the generator 9 of the counting pulses, and the counter 12, connected to the output of the counter 12, successively connected to the zero display circuit 13 of three undercarriage AND circuit 14, a second input coupled to an output jreHepaTopa 9 countable pulses.

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and the third input is with the second output of the generator 10 of the calibration time interval, and the unit 15 is raising the number to the fourth power, the counter 12 is reversible, and its second input is connected to the output of the three-input circuit 14.

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

The generator 1 of sync pulses generates a sequence of pulses arriving at one of the inputs of the block 2 forming a control interval, the second input of which receives the pulses of the generator 9 counting pulses. At the output of the control interval generation unit 2, a sequence of pulses is generated, the duration of which is equal to the pulse detection period of the 9 counting pulses, and the repetition frequency corresponds to the synchronizer pulse frequency 1. The leading edge of the pulse of the control interval formation unit 2 oscillates the ultrasonic oscillator 3, which excites ultrasonic vibrations transmitting electroacoustic transducer 4, radiating them into a controlled product 16. Receiving electroacoustic ustichesky converter 5 converts pulses of ultrasonic oscillations passed through the controlled product 16 into electrical pulses and feeds them to the input of amplifier 6, whose output signals are input to Stop shaper 7, the measured time interval. At the input of the start of the imaging unit of the measured time interval, pulses are received from the output of the control interval formation unit 2, corresponding to the leading edge of the pulse generated by them. I.

Thus, at the output of the imaging unit 7 of the measured time interval, pulses are obtained, the duration of which is equal to the transit time of ultrasonic oscillation pulses in the monitored product 16. These pulses go to one of the inputs of the time discriminator 8, to the second input of which pulses are output from the control interval forming unit 2 . Supporting

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the interval is the pulse from the output of the imager 7, which is measured by the time interval. If the pulse duration at the output of the imager 7 5 of the measured time interval is not equal to the pulse duration at the output of the control interval formation block 2, then the time discriminator 8 generates a voltage

10 of the corresponding polarity, which is fed to the input of the generator 9 of counting pulses and adjusts its frequency so that the duration of these pulses becomes equal to J5. From the output of the generator 9 counting pulses, the signals arrive at one of the inputs of the selector 11, the second input of which receives pulses from the first output of the generator 10 of a calibrating time interval, the duration of which is chosen to be numerically equal to the product of the value of the sounding base by a factor K equal to. The number of pulses per

25 output selector 11 is equal to product. the velocity of the ultrasonic oscillations V by a factor K. From the output of the selector, the pulses are post-entry to the input of the first counter 12.

This ends the first cycle of the device. In the second cycle of operation, the beginning of which corresponds to the leading edge of the pulse at the second output of the generator 10 of the calibration time interval,

 carried out in accordance with formula (1), calculating the fourth power of the number stored in the counter 12.

The counting pulses from the output of the generator 9 of the counting pulses through the three-input circuit AND 14 are fed to the subtractions of the input of the counter 12 and to the input of the unit 15 for raising the number to the fourth power until the counter 12 goes to the zero state. In this case, the zero indication circuit 13 i changes its state and thereby prevents the passage of pulses from the generator 9 of the counting 50 pulses through the AND t4 circuit, and the number stored in the counter 12 that is numerically equal to V turns out to be entered into the fourth power raising unit 15, with

55 with which receive the value of strength R according to the formula (1).

The application of the invention ensures the achievement of a positive

the effect of expanding the functionality of the device by directly determining the strength of the concrete, which increases the control performance, reduces the laboriousness of testing the concrete for strength.

Claims (1)

A DEVICE FOR DETERMINING CONCRETE STRENGTH, containing a serially connected clock generator, a control time interval generating unit, an ultrasonic vibration generator, an emitting electro-acoustic converter, an electro-acoustic receiving transducer, an amplifier, a measured time interval shaper, a time discriminator and a counting pulse generator, the output of which is connected to the second input block formation control in-, time-out, the output of the latter is connected to the second the inputs of the time discriminator and the shaper of the measured time interval, connected in series to the generator of the calibration time interval, a selector, the second input of which is connected to the output of the counter pulse generator, and a counter, characterized in that, in order to expand the functionality, it is equipped with series-connected to the output of the counter connected by a zero indication circuit, a three-input AND circuit, the second input of which is connected to the output of the counting pulse generator, and the third input with a second output the generator of the calibration time interval, and the block raising the number to the fourth degree, the counter is made reversible, and its second input is connected to the output of the three-input circuit I.