Effective stress level test device and method of vertical prestressed reinforcement

A technology of vertical prestress and effective stress, applied in measuring devices, force/torque/work measuring instruments, instruments, etc., to ensure effectiveness, eliminate limitations, and have the effect of tensioning quality

Active Publication Date: 2012-08-15
RES INST OF HIGHWAY MINIST OF TRANSPORT
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Problems solved by technology

[0005] The purpose of this invention is to provide a kind of vertical prestressed reinforcement effective stress level testing device and its testing method, to solve the technical problem of vertical prestressed reinforcement effective stress level test in the box girder web; and solve how to quantify the temperature to stress Influence of measurement accuracy

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  • Effective stress level test device and method of vertical prestressed reinforcement
  • Effective stress level test device and method of vertical prestressed reinforcement
  • Effective stress level test device and method of vertical prestressed reinforcement

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specific Embodiment

[0098] The specific embodiment is as follows: according to step one to step seven, the total length L of the vertical prestressed reinforcement obtained through measurement is 3.030m, and the thickness D of the upper anchor backing plate 1 and the thickness D of the lower anchor plate 2 Both are 0.020m, the distance D between the upper and lower anchor plates 3 is 2.657m, the outer diameter D of the vertical prestressed reinforcement 4 = 32mm, the effective stress length L of the steel bar e =D 1 +D 2 +D 3 +D 4 =2.729m; the acoustic time values ​​of the vertical prestressed steel bars collected by the ultrasonic transducer before and after loading are S 1 =508559ns, S 2 =513927ns, the temperature values ​​before and after the vertical prestressed steel bar are stressed are respectively t 1 =25°C, t 2 = 28°C, calculated by the ARM processor, using the formula obtained in step 6 to calculate the effective stress level of the vertical prestressed steel bar is 610.454MPa,...

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Abstract

The invention discloses an effective stress level test device and method of a vertical prestressed reinforcement. An ARM (Advanced RISC Machines) processor is connected with an ultrasonic pulse generator; a pulse signal emitted from the ultrasonic pulse generator is transmitted to an ultrasonic transducer via a boosted circuit and a transmitter circuit; the ultrasonic transducer transmits the ultrasonic wave to a data register via a programmable filter, a programmable amplifier and an A/D (analog-to-digital) converter; collected signals are sent to a DSP (Digital Signal Processor) by the data register; the DSP stores the signals in an RAM (Random-Access Memory) storage area; the ARM processor is connected with a memory, a keyboard, a display, the programmable amplifier, the programmable filter, the RAM storage area and a temperature measurement circuit; and the temperature measurement circuit is connected with a temperature sensor. The device has the characteristics of no loss, high speed, high accuracy and low cost, especially can quantify the influence of temperature on a stress measurement result, can correct the stress level test error of the vertical prestressed reinforcement so as to obtain the effective stress level value of the vertical prestressed reinforcement with the engineering accuracy.

Description

technical field [0001] The invention belongs to the field of non-destructive testing, and relates to a device and a method for testing the effective stress level of vertical prestressed reinforcement applied to the web of a box girder. Background technique [0002] The vertical prestressed tendons of the bridge structure act on the web of the box girder (the web of the long-span concrete box girder), which is the key structure to bear the shear stress and main tensile stress of the section. In bridge construction, due to the limited height of the box girder , the length of the vertical prestressed reinforcement (relative to the longitudinal prestressed reinforcement) is relatively short, so the elongation of the reinforcement is limited when the tensile control stress is reached. If there is a slight deviation during the anchoring and anchoring process, the effective stress will easily The level cannot meet the design requirements or even stress failure; affected by the cons...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): G01L5/00
Inventor 张劲泉傅宇方张科超李万恒郑毅
Owner RES INST OF HIGHWAY MINIST OF TRANSPORT
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