JP5690255B2 - Performance confirmation test method and apparatus for surface covering material of RC structure - Google Patents

Description

  The present invention relates to a performance confirmation test method and apparatus for a surface covering material of an RC (Reinforced Concrete) structure.

  The performance of RC structures deteriorates due to corrosion of reinforcing bars caused by salt damage. Then, in order to improve the resistance with respect to corrosion of the reinforcing bar of RC structure, there is an example which constructs a surface covering material to RC structure.

  Hereinafter, the existing technology will be described.

  The existing technologies for confirming the performance of the surface covering material of the RC structure are roughly classified into an exposure test and a deterioration promotion test.

  Considering that the civil engineering structure has been in service for 50 years or more, an exposure test that requires a test period equivalent to that is difficult to practically use.

  In addition, in general deterioration promotion tests, it is necessary not only to reinforce the reinforcing bars in the concrete in order to check the corrosion amount of the reinforcing bars, but also to provide specimens for each parameter such as the diameter of the reinforcing bars and concrete cover. The problem remains in economic efficiency.

  In addition, common to existing technologies, it is difficult to predict deterioration with a reinforcing bar diameter or concrete cover different from the test conditions.

Japanese Patent Laid-Open No. 2007-240481

  As described above, the exposure test of the surface covering material of the RC structure has a problem of the length of the test period, and the deterioration acceleration test has a tendency to increase the number of required specimens. Thus, the present condition is that the rational method which confirms the performance of the surface coating material of RC structure is not established.

  The reason why the number of specimens increases in the deterioration promotion test is that it is necessary to lift the reinforcing bar from the concrete in order to grasp the corrosion amount of the reinforcing bar. This problem is solved if it is possible to monitor the progress of corrosion of one specimen throughout the test period.

  As such corrosion monitoring, for example, a method for predicting rebar corrosion and a monitoring system for rebar corrosion (see Patent Document 1 below) have been proposed. In this monitoring method, a reinforcing bar embedded in a member is divided into a plurality of reinforcing bar elements, and a sensor box in which a reference electrode and a counter electrode, a concrete resistance meter, and a concrete thermometer are stored is embedded in concrete. The computer controls the corrosion monitor and the switching device, and measures the electrochemical properties using the sensors in the sensor box.

  However, the method for predicting corrosion of reinforcing bars and the monitoring system for corrosion of reinforcing bars disclosed in Patent Document 1 described above have a problem that the scale of the apparatus is large and the test is complicated.

  In view of the above circumstances, an object of the present invention is to provide a method for confirming the performance of a surface covering material for an RC structure and an apparatus therefor, in which the number of test items is small and the test is simple.

In order to achieve the above object, the present invention provides
[1] In performance test method for the surface dressing of RC structures, using a strain gauge to correspond to the surface of the RC structure denoted by the surface coating material, a data logger connected to the strain gauge, said surface perform electrolytic corrosion testing rebar of RC structure denoted by the coating material, based on it was tested the degree of resistance to corrosion of the reinforcing steel by surface coating material of the RC structure, RC structure denoted by the surface coating material It is characterized by predicting the long-term deterioration and the progress of the.

  [2] In the performance confirmation test method for the surface covering material of the RC structure according to [1] above, the electrolytic corrosion test estimates a reinforcing bar expansion amount due to corrosion by numerical analysis.

[3] In the performance confirmation test apparatus for the surface covering material of the RC structure, using the strain gauge installed on the surface of the RC structure with the surface covering material and the data logger connected to the strain gauge, the surface perform electrolytic corrosion testing rebar of RC structure denoted by the coating material, based on it was tested the degree of resistance to corrosion of reinforcing steel RC structures by surface coating material, RC structure denoted by the surface coating material It is characterized by comprising means for predicting the long-term deterioration and the progress of the deterioration.

  According to the present invention, it is possible to provide a method and apparatus for confirming the performance of a surface covering material for an RC structure, which requires fewer test items and is easy to test.

It is a cross-sectional schematic diagram of the reinforcing bar of the RC structure specimen in which corrosion of the reinforcing bar has occurred. It is a performance confirmation test conceptual diagram of the surface covering material of the RC structure specimen according to the present invention. It is a schematic diagram of the performance confirmation test apparatus of the surface coating material of the RC structure specimen according to the present invention. It is a figure which shows the example which the surface coating material of the RC structure test body concerning this invention confirms performance.

Performance test method for the surface dressing of RC structures, using a strain gauge to correspond to the RC structure specimen surface marked with surface coating material, a data logger connected to the strain gauge, the surface coating material was subjected to electrolytic corrosion test of RC structures specimen rebar was subjected, on the basis of which to test the degree of resistance to corrosion of the reinforcing bars by RC structures specimen of the surface covering material, RC structure denoted by the surface coating material Predict the long-term degradation and progress.

  Hereinafter, embodiments of the present invention will be described in detail.

  FIG. 1 is a schematic cross-sectional view of an RC structure specimen in which corrosion of a reinforcing bar has occurred.

  In this figure, 1 is an RC structural specimen, 2 is a reinforcing bar, 3 is concrete, 4 is a concrete surface, 5 is a reinforcing bar volume strain, and 6 is a concrete surface strain.

  Thus, since the reinforcing bar 2 expands in volume due to corrosion, the surface of the concrete 3 is distorted by the influence thereof.

  Using this fact, the amount of expansion of the reinforcing bars due to corrosion is estimated using a strain gauge (see FIG. 4) installed on the surface of the RC structural specimen 1 and a data logger (see FIG. 3) connected thereto.

  FIG. 2 is a conceptual diagram of the performance confirmation test of the surface covering material of the RC structure specimen according to the present invention. FIG. 2 (a) shows the case without the surface covering material (comparative example), and FIG. 2 (b) shows the surface covering material. It is a figure which shows a case.

  In FIG. 2B, reference numeral 7 denotes a surface covering material attached to the concrete surface 4 of the RC structure specimen.

  As shown in FIG. 2, the performance of the surface covering material 7 can be confirmed by the progress of corrosion of the reinforcing bars of the RC structure specimen measured as the magnitude of the concrete surface strain.

FIG. 3 is a schematic diagram of a performance confirmation test apparatus for a surface covering material of an RC structure specimen according to the present invention.
In this figure, 11 is an RC structure specimen with a surface covering material 14 , 12 is a reinforcing bar, 13 is concrete, 15 is a performance confirmation test device for the surface covering material 14, and is arranged so as to correspond to the surface covering material 14. And a data logger 17 connected to the strain gauge 16.

  By using this, the long-term deterioration of the RC structural specimen 11 (reinforced concrete member) with the surface covering material 14 and its progress are predicted.

A strain gauge 16 is installed on the surface of the RC structural specimen 11 provided with the surface covering material 14 and on the top of the reinforcing bar 12, and the surface strain of the concrete 13 is measured. Since the reinforcing bar 12 expands due to corrosion, the surface of the concrete 13 is distorted by the influence thereof. Therefore, numerical analysis by FEM (finite element method) etc. can be performed using the measured surface strain to predict the progress of corrosion of the reinforcing bars.

  Further, by modeling the relationship between the reinforcing bar volume strain and the concrete surface strain, the corrosion amount of the reinforcing bar can be predicted without lifting the reinforcing bar in the concrete. Thereby, the progress of corrosion of the reinforcing bars can be monitored throughout the test period.

  FIG. 4 is a view showing an example of confirming whether or not the surface covering material of the RC structure specimen according to the present invention satisfies the performance, and the horizontal axis indicates the accumulated current amount and the vertical axis indicates the surface strain. .

  As shown in this figure, for example, measure the surface strain of an unmeasured specimen (in the case of a comparative example without a surface covering material) C, a covering material A to be compared, and a specimen provided with a covering material B. . When a constant integrated current is passed, the performance of the coating is checked or confirmed by comparing the strain reduction rate with respect to the strain of the unmeasured specimen and the allowable value of the surface strain. For example, in FIG. 4, surface distortion appears significantly in the non-measured specimen C, which far exceeds the allowable value R. On the other hand, in the case of the surface covering material B, the surface strain is reduced, but the allowable value R is exceeded. On the other hand, in the case of the surface coating material A, the surface strain is very small and becomes an allowable value R or less, and it can be said that the resistance to corrosion of the reinforcing bars by the surface coating material A is larger than that of the surface coating material B. In this way, a confirmation test of the performance of the surface covering material can be performed.

Thus, the degree of corrosion of the reinforcing bars can be measured by the degree of surface strain of the RC structure specimen provided with the surface covering material . Based on this, it is possible to monitor the progress of corrosion of the reinforcing bar of the RC structure specimen with the surface covering material and the improvement of the resistance to corrosion of the reinforcing bar by the surface covering material.

  In addition, this invention is not limited to the said Example, Based on the meaning of this invention, a various deformation | transformation is possible and these are not excluded from the scope of the present invention.

  The RC structure surface covering material performance confirmation test method and apparatus thereof according to the present invention is a small scale and simple test, and the RC structure specimen surface covering material performance confirmation test method and apparatus thereof Is available.

1 RC structural specimen 2,12 Reinforcing bar 3,13 Concrete 4 Concrete surface 5 Reinforced volume strain 6 Concrete surface strain 7,14 Surface coating material
Performance test apparatus 16 of the RC structures specimen 15 surface coating material marked with 11 surface coating material strain gauge 17 Data Logger

Claims (3)

And strain gauges correspond to RC structures specimen surface marked with surface coating material, the strain using a data logger that is connected to the gauge, the electrolytic corrosion test of RC structures specimen rebar marked with the surface coating material done, it was tested the degree of resistance to corrosion of the reinforcing bars by RC structures specimen of the surface covering material, to predict the long-term deterioration or the progress of RC structures specimen marked with the surface coating material on the basis thereof A method for confirming the performance of a surface covering material for an RC structure characterized by the following.   The performance check test method for a surface covering material of an RC structure according to claim 1, wherein the electrolytic corrosion test estimates a reinforcing bar expansion amount due to corrosion by numerical analysis. Confirmation test method. Using the strain gauge installed on the surface of the RC structure specimen with the surface coating material and the data logger connected to the strain gauge, the corrosion test of the reinforcing bars of the RC structure specimen with the surface coating material was conducted. performed, based on it was tested the degree of resistance to corrosion of the reinforcing bars by RC structures specimen of the surface covering material, means for predicting the long-term deterioration or the progress of RC structures specimen marked with the surface coating material An apparatus for confirming the performance of a surface covering material for an RC structure , comprising:

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