JP4229277B2 - Method for repairing concrete defects generated during construction of concrete structure and vibrator used for repairing the concrete defects - Google Patents

Description

  The present invention relates to a method for repairing a concrete defect generated during construction of a concrete structure and a vibrator used for repairing the concrete defect.

  In recent years, the necessity of ensuring the quality of concrete structures has been reaffirmed. In particular, effective measures are being sought to reduce the quality and shorten the life of structures due to jumpers generated during the construction of concrete structures. .

In general, in order to prevent the occurrence of jumpers, concrete is placed in a mold and then compacted (Patent Documents 1 and 2). In addition, when a jumper is formed as a bean-plate-like concavo-convex portion on the surface of the cast concrete in spite of such treatment, partial repair is performed by filling the concavo-convex portion with repair mortar (Patent Document 3).
JP 6-60530 Japanese Patent Publication No. 2-55587 JP-A-8-284427 JP 2001-337074 A Japanese Patent No. 2836799

  In the method of Patent Document 3 described above, the integrity of the repaired part and the original concrete cannot always be ensured, and the quality cannot be guaranteed over a long period of time.

  On the other hand, as a method for examining the internal state of a concrete structure, nondestructive inspection by an ultrasonic method (Patent Document 4), an electromagnetic induction method (Patent Document 5), etc. has been conventionally performed. Although it is possible to remove the junker that has occurred after placing the concrete and before hardening by applying vibrational energy to the place of occurrence, it is unclear when the vibration should be applied. Inadequate repair, or too long, causes inconvenience such as delay in construction period.

  The applicant of the present application has found that the vibration time (more precisely, vibration energy) required for repairing the jumper before hardening the concrete depends on the elapsed time from the completion of concrete placement and the pressure applied to the vibration location. The concrete structure is characterized in that the vibration time or vibration energy is determined as a function of the elapsed time from the completion of the placement or the height from the vibration location to the top of the concrete and the vibration of the required time or energy is applied. An object of the present invention is to provide a method for repairing a concrete defect during construction of an object.

The first means is
When repairing defects such as junkers that occur during the curing period after concrete placement and before curing by oscillating the defect occurrence site, the total amount of vibration energy necessary for repairing the defect is placed in the concrete placement. According to the elapsed time t from time, a method for repairing defects that occurred during the construction of the concrete structure determined based on the data created in advance for the correlation between the amount of energy and the elapsed time ,
The vibration time T required for repairing a concrete defect when the vibration energy is applied at a constant rate in time is determined by the following Equation 1.
[Formula 1] T = A × t ² + B (A and B are time constants)

In the present specification and claims, the “concrete defect” includes an unfilled portion that occurs without the concrete material reaching the corners of the formwork in addition to the junkers.
In the detailed description of the invention of the present specification, “when concrete is placed” means when the work of placing concrete into the mold is completed, and the disclosure column and claims of the invention are completed. It is desirable to interpret the same in the range of.

  Further, it is desirable to create data indicating the correlation between the total amount of vibration energy and the elapsed time of the concrete for each vibrator that applies the vibration.

  The second means includes the first means, and records and records the correlation between the total amount of the vibration energy and the elapsed time from the concrete placement.

The third means has the above-mentioned first means, and the time constants A and B are determined by the following formulas 2 to 3 using the height H from the vibration location to the top of the concrete as a variable. ing.
[Formula 2]

A = a ₁ × H + a ₂ (where a ₁ and a ₂ are constants relating to H)
[Formula 3]

B = b ₁ × H + b ₂ (where b ₁ and b ₂ are constants relating to H)
Fourth means includes said first means or third means, and the right side of the above equation 1, is multiplied by the correction coefficient S about Slump S _L of ready-mixed concrete, T = S × (A × t ² + B), and the correction coefficient S is expressed by the following Equation 4.
[Formula 4]

S = s ₁ × S _L ² + s ₂ × S _L + s ₃
Fifth means includes one of the first means to the fourth means, and the mold portion corresponding to Janka occurrence point of the mold that Da設the concrete, before the addition of vibration The content is to form the air holes 7.

Sixth means has one of said first means to the fifth means, and has the content that the frequency was 130～250Hz.

The seventh means is a vibrator for repairing a concrete defect generated during construction of a concrete structure,
A vibrator main body 22 and a processing device 23 with an arithmetic function provided with an information input unit 26,
When the time information necessary to obtain at least the elapsed time after concrete placement is input to the information input unit 26, the processing device 23 uses the vibrator main body 22 according to the elapsed time. The required vibration time for repairing the jumper is calculated, and the vibrator main body 22 can be vibrated only within the calculated required vibration time . The processing device 23 is applied to the cast concrete. When the height from the place of vibration to the top of the concrete is input to the information input unit 26, the required vibration time for repairing the jumper is corrected and calculated according to the height.

  As a specific structure for calculating the vibration time required for the above-mentioned jumper repair, for example, Formula 1 described in the second means and coefficient data specific to the vibrator main body included in the formula are recorded. The computer may be built in the processing device 23.

  The processing device 23 may only calculate the required vibration time and display it to the user, or controls the operating state of the vibrator main body according to the calculated time as described in the eleventh means described later. But it ’s okay. Further, the processing device 23 may be integrally attached to the outer surface of the vibrator main body, or may be provided separately from the processing device.

The eighth means has the seventh means , and the processing device 23 measures the vibration time from the start of the vibrator main body, and the measured vibration time becomes the required vibration time for the junker repair. When it reaches, the vibrator main body 22 is automatically stopped.

The invention according to the first means has the following effects.
○ Because the total amount of vibration energy required for repairing defects is determined based on the data created in advance for the correlation between the amount of energy and the elapsed time, depending on the elapsed time since concrete placement. Energy saving can be achieved.
○ Since the vibration time required for repairing the jumper is given by Equation 1 (T = A × t ² + B) including the function of the elapsed time t, the required vibration time required for repairing the concrete defect (hereinafter referred to as convenience) Therefore, the work process can be carried out quickly.
In the above formula 1, since the first-order coefficient of t is zero, the required vibration time T does not become a decreasing function with respect to t at t = 0 or in the vicinity thereof, and vibrates in a relatively short time after placing concrete. In view of the qualitative nature of the concrete that the hardness gradually increases during the curing period, the calculated value of the required vibration time T is not unduly small.

  In the invention according to the second means, since the above-mentioned correlation is charted, the required amount of vibration energy can be immediately determined from this table.

In the invention according to the third means, since the time constants A and B are a linear function of the height H from the excitation location to the top of the concrete, the required vibration time value can be corrected by the height, The vibration time can be determined more accurately.

In the invention according to the fourth means, because the slump value S _L of freshly mixed concrete was added as a correction factor in the equation 1 can be determined more accurately vibration time.

In the invention according to the fifth means, since the air vent hole is drilled in the surface of the jumper occurrence location, the junker can be repaired quickly by facilitating the discharge of the gas existing in the jumper occurrence location. .

In the invention according to the sixth means, since the frequency is set to 130 to 250 Hz, the repair area ratio of the jumper can be improved.

In the invention according to the seventh means, since the vibrator main body 22 and the processing device 23 for calculating the required repair time for repairing the junker using the vibrator main body are provided, the index of the required repair time is repaired. It can be easily performed in the process. Moreover, in the invention which concerns on the 7th means, since it provided so that the required vibration time for a junker restoration might be corrected with the height from the excitation location to the concrete cast to the top of the concrete, the junker restoration is more reliable. And can be done quickly.

In the invention according to the eighth means, the processing device 23 automatically stops the vibrator main body 22 when the vibration time from the start of the vibrator main body reaches a required vibration time for repairing the junker. As a result, the junker repair work is further simplified.

  Hereinafter, FIGS. 1 to 11 show a first embodiment of a method for repairing a concrete defect generated during construction of a concrete structure according to the present application.

  FIG. 1 shows a concrete form 1 to which the method of the present invention is applied. As is well known, concrete construction is carried out through various steps in which ready-mixed concrete is driven into a formwork, vibrated with a vibrator, etc., compacted, cured for a certain period, and demolded. 1 is filled with concrete 2 under curing. Reference numeral 21 denotes a vibrator for vibrating the concrete jumper generating portion 3 in the concrete mold 1.

  When repairing a jumper by the method of the present invention, first, the time when the concrete placing work is completed is recorded.

  Next, during the curing period, the concrete under construction is inspected at any time using a known junker inspection device to check for the occurrence of junkers. Since the jumper is likely to be generated at the leg portion of the vertical member such as a column or a wall and the turning hitting position, it is preferable to inspect these points with priority.

  When the jumper is detected, the height of the concrete portion above the jumper (hereinafter referred to as “upper concrete”), that is, the height H from the jumper occurrence point 3 to the top edge 4 of the concrete is measured.

  Next, the elapsed time t and the height H of the upper concrete are applied to the following table prepared in advance for each vibrator to obtain the required vibration time T for the junker repair. During the time, the vibrator 21 If vibration is applied to the place where the jumper is generated, the jumper can be repaired in the minimum necessary time. After the junka is restored, the concrete should continue to be cured. In addition, how to obtain the numerical values in this table will be described later.

  When the following Table 1 is used for another vibrator having vibration energy per unit time N times with respect to the vibrator to which this table is applied, vibrations 1 / N times the numerical values in this table. Take time.

この表１は、ジャンカの修復に関して得られた次の知見に基づいて作成されている。上記表１中の振動時間Ｔは、ジャンカを修復するための振動エネルギーに比例している。本出願人は、これら振動時間乃至振動エネルギーと、ジャンカが発現した面積のうち修復された割合（以下「ジャンカ修復面積率」という）との関係を調べるために図２の様なコンクリート型枠11を用いて実験を行った。まず該コンクリート型枠内に、型枠前壁12と一定の間隔を保って仕切り板14を挿入して型枠前壁12と仕切り板14との間の間隙内へジャンカの代わりとなる砂利15を充填するとともに、又仕切り板14と型枠後壁13との間の空間内へ生コンクリート２を打設し、次に図２(a)に矢示する如く仕切り板14を引き抜いて得られる試験体でジャンカが現れたコンクリートの状態を再現した。この装置において、上部コンクリートの打設高さHがある場合を再現するときには、図２(b)に示す如く適当な加圧機16を使用して上記コンクリート型枠11の上面全体を、上記Hに対応する圧力で押圧する。尚、この実験での型枠の大きさは横幅ｄ₁＝40cm、奥行きｄ₂＝15cm、高さｈ＝40cmであり、又、砂利層の厚みは２cmである。又、コンクリート材料としては、関東地方で得られた標準的な粘度を有するコンクリート材料であって、W/C＝55％でのスランプ値が18cm程度のもの（以下「基準コンクリート」という）を用いた。

This Table 1 is prepared based on the following knowledge obtained regarding the restoration of Junka. The vibration time T in Table 1 is proportional to the vibration energy for repairing the jumper. In order to investigate the relationship between the vibration time or vibration energy and the proportion of the area where the jumper has been repaired (hereinafter referred to as “junker restoration area ratio”), the applicant of the present invention is shown in FIG. The experiment was conducted using. First, a partition plate 14 is inserted into the concrete formwork at a certain distance from the formwork front wall 12, and gravel 15 instead of a junker is inserted into the gap between the formwork front wall 12 and the partition plate 14. Is obtained by placing the ready-mixed concrete 2 in the space between the partition plate 14 and the rear wall 13 of the formwork, and then pulling out the partition plate 14 as shown by the arrow in FIG. The condition of the concrete in which junka appeared in the test specimen was reproduced. In this apparatus, when reproducing the case where the upper concrete has a placement height H, the entire upper surface of the concrete formwork 11 is set to H by using a suitable press 16 as shown in FIG. Press with the corresponding pressure. Note that the size of the mold in this experiment is the width d ₁ = 40 cm, the depth d ₂ = 15 cm, the height h = 40 cm, and the gravel layer thickness is 2 cm. The concrete material is a concrete material with a standard viscosity obtained in the Kanto region, with a slump value of about 18 cm at W / C = 55% (hereinafter referred to as “standard concrete”). It was.

When four specimens as described above are manufactured and 45 minutes have passed after placing concrete, three types of handheld vibrators V ₁ , V ₂ and V ₃ and one kind of vibrator with a wall are used. Vibration was applied using V ₄ and each. Each frequency of the vibrator V ₁ ~V ₃ is 173Hz, 140 Hz, is 140 Hz, also doubled, per unit of vibrators V ₃ times of the vibration energy vibrator V ₁ of the per unit time vibrator V ₂ the vibration energy of about 2.8 times the vibrator V _1, vibrational energy per unit time vibrator V ₄ is approximately 0.5 times the vibrator V _1.

Incidentally, the total vibration energy E of the vibrator is generally given by the following formula 5. In the equation, m is the mass of the vibrator, A is the amplitude of the vibrator, f is the vibration frequency of the vibrator, and t is the vibration time. In the vibrator V ₂ used in the experiment, m = 197.5 g, A = 23.5 mm, and f = 140 Hz.
[Formula 5]

E = m × (π × A × f) ² × t
FIG. 3 shows the result of the experiment according to FIG. In the hand-held type vibrator, it was found that when the vibration time is increased, the repair area ratio of the junker increases, and when the fixed vibration time is given, the repair ratio of the jumper reaches 100%. In this experiment, when the wall-mounted vibrator V ₄ was used, the junker repair area ratio did not reach 100% within the experiment time, because the output of the vibrator V ₄ is the vibrator V It is understood that it is about half that of ₁ . In order to make the junker repair area 100% within a practical time, the output of the vibrator used is the output of the vibrator V ₁ (3.77 × 10 ⁷ [g * mm ² * Hz ² * s ]) It is desirable to set the same level or higher.

Further, the vibration time to Janka repair area ratio is 100%, vibrator V ₂ at about 1/2 relative to the vibrator V _1, also were vibrator V ₃ at about 1/4. Therefore, if Table 1 is created for vibrators having a certain vibration energy per unit, the numerical values in the table are 1 / N times the other vibrators having N times the vibration energy as described above. By doing so, an appropriate vibration time can be roughly estimated.

Further, according to Equation 5, the vibration energy E of each vibrator is expressed as a quadratic function of the frequency f of the pendulum in the vibrator. It is understood that this amount of energy is transmitted almost as it is to the concrete with a slump value close to zero, but even in the concrete with a slump value of about 15 to 20 cm, which is generally used for construction, vibration There is no guarantee that the vibration energy of the machine will be directly received by the ready-mixed concrete. Therefore, when the applicant conducted an additional test in the vibration experiment using the vibrator V ₁ with the initial frequency (173 Hz) changed, the vibration time was increased to 1.25 times when the frequency was 0.8 times (143 Hz) and the frequency was increased. However, at 1.13 times (195 Hz), it was found that the vibration time should be 0.88 times. Therefore, when the frequency can be changed in the same vibrator, the vibration time given in Table 1 should be 1 / N times when the frequency is increased N times.

  Further, from the above experimental results, it is estimated that there is a close relationship between the vibration energy applied to the location where the jumper is generated and the vibration time for repairing the jumper. In this embodiment, the vibration time is determined. The elapsed time after placing concrete was considered as the first factor. The reason is that the concrete will harden over time and the yield value of the concrete will increase, and it is expected that much vibration energy will be required to remix the aggregate and cement part of the concrete beyond the yield value. Because it is done. Furthermore, the height of the above-mentioned upper concrete was taken into consideration as a second factor for determining the vibration time for the above-mentioned junker restoration. This is because the greater the height, the greater the pressure at the location where the jumper is generated, thereby increasing the yield value of the concrete. Therefore, the following experiments were conducted on the time dependency and pressure dependency of the yield value of the concrete.

Fig. 4 shows the relationship between the vibration energy applied to the location where the junker is generated and the junker repair area ratio, immediately after placing (L ₁ ), 30 minutes after placing (L ₂ ), and 45 minutes after placing (L ₃ ) and graphs for 60 minutes after placement (L ₄ ). From this graph, it was found that as the elapsed time after placement was longer, more vibration energy was required as expected.

FIG. 5 shows the relationship between the vibration energy applied to the location where the junker is generated and the junker repair area ratio, when the upper concrete placement height is 0 (L ₅ ), 0.1 m (L ₆ ), The graph shows the case of 0.25 m (L ₇ ) and the case of 0.50 m (L ₈ ). From this graph, it can be seen that the greater the placement height of the upper concrete, the more vibration energy is required.

6 repeats the experiment shown in FIG. 4 under different conditions (placement height of the upper concrete), and shows the elapsed time t after placement and the vibration time T for making the junker repair area 100%. The relationship is plotted. In FIG. 6, L ₉ represents the case where the upper concrete placement height is 0.50 m, L ₁₀ is 0.25 m, L ₁₁ is 0.10 m, and L ₁₂ is zero. Yes.

7 repeats the experiment shown in FIG. 5 under different conditions (elapsed time after concrete placement), and shows the elapsed time t after placement and the vibration time T for setting the junker repair area to 100%. The relationship is plotted. In FIG. 7, L ₁₆ is immediately after placing, L ₁₅ is 30 minutes after placing, L ₁₄ is 45 minutes after placing, and L ₁₃ is 60 minutes after placing. Each case represents a time of 0.50 m. The results of these experiments are summarized in Table 1.

  FIG. 8 shows the core compressive strength of the concrete whose junker is repaired by the method of the present invention. The broken line in the figure shows the core strength of the repaired concrete at each junker repair area ratio, and the alternate long and short dash line in the figure shows the core compressive strength of the concrete without the junker at the age of 35 days or more, respectively. However, when the repair area ratio of junker is 92% or more, the core compressive strength of the repaired concrete is almost inferior to the concrete that has not yet developed junker. The compressive strength experiment in FIG. 8 was performed by applying a vertical pressure to a columnar test body having a diameter of 10 cm and a height of 20 cm.

  FIG. 9 to FIG. 11 are modifications of the first embodiment. Based on the data shown in Table 1, the vibration time T for the junker repair and the elapsed time t to the height H of the upper concrete are shown. This is a mathematical expression of the correlation.

  The correlation was analyzed by the method of least squares. As a result, it was found that the vibration time T for repairing the junker is preferably expressed as a quadratic function of the elapsed time t and expressed as a linear function of H. Specifically, the vibration time T (s) is determined by substituting the elapsed time t (min) into the following Equation 1.

T = A × t ² + B (Formula 1)
However, A and B in the right side of the above formula 1 are determined by substituting the concrete height H (m) above the junker into the following formula 2 and formula 3.

A = a ₁ × H + a ₂ (Formula 2) B = b ₁ × H + b ₂ (Formula 3)
However _{a 1, a 2, b 1} , b 2 are constants related to H. The values of these constants determined from the data in Table 1 are a ₁ = 0.0488 (s / m * min ² ), a ₂ = 0.0016 (s / min ² ), b ₁ = 65.116 (s / m), b ₂ = 20 (s).

Next, the process that led to the introduction of Equation 1 to Equation 3 will be described. First, when the data in Table 1 and FIG. 6 are directly formulated into the form of T = αt ² + βt + γ by the least square method, the coefficients α, β, γ and the least square error R ² shown in the following Table ² are obtained. It was.

しかし上記近似式では右辺中の１次係数βが負なので、ｔ＝０及びその近傍においてジャンカ修復のための振動時間Ｔはｔの増加に伴って減少することになるが、上述の通り定性的にはｔに対して増加関数となる筈であり、このままでは経過時間ｔが零の時の意味合いも不明確となる。

However, since the first order coefficient β in the right side is negative in the above approximate expression, the vibration time T for repairing the junker at t = 0 and in the vicinity thereof decreases as t increases. Is an increase function with respect to t, and the meaning when the elapsed time t is zero becomes unclear if it remains unchanged.

In order to improve this point, Formula 1 in the form of T = At ² + B is newly adopted as an approximate formula, and A and B are determined so that the error between the calculation result by this formula and the experimental data is minimized. did.

  Specifically, from the vibration time T at t = 0, 30, 45, 60 (min) described in Table 1, the vibration time T at t = 0 (corresponding to the coefficient B in Equation 1) ), And the elapsed time t in Table 1 is replaced with the square value of t to obtain the following Table 3. The result is shown in FIG.

表３及び図９中の上部コンクリート打設高さＨ毎の振動時間Ｔの実験値の折れ線Ｌ₉〜Ｌ₁₂に関して、これら各線との誤差が最小となる近似直線を決定してその傾きＡを求め、上記係数Ｂとともにまとめると、次の表４を得る。

Regarding the broken lines L _{9 to} L ₁₂ of the experimental values of the vibration time T for each upper concrete placement height H in Table 3 and FIG. 9, an approximate straight line that minimizes the error from each of these lines is determined, and the inclination A is determined. When obtained and summarized together with the coefficient B, the following Table 4 is obtained.

Based on the data in Table 4, when the dependence on the height H of the upper concrete is plotted for each of the coefficient A corresponding to the slope of Formula 1 and the coefficient B corresponding to the vertical axis intercept of the formula, FIG. In addition, an approximate straight line that minimizes an error from the numerical value of each of the coefficient A and the coefficient B is determined, and the coefficient a of the above formula 2 is determined from the slope and vertical axis intercept of the approximate line of the coefficient A ₁ and a ₂ , and the coefficients b ₁ and b ₂ of Equation 3 can be obtained from the slope of the approximate line of the coefficient B and the vertical axis intercept, respectively.

図11は、上記の如く決定した各係数を代入した数式１を、ジャンカ修復時間の実験値に重ねたものであり、当該時間の計算値と実験値とがかなり良く一致していることを示している。

Fig. 11 is a result of superimposing Equation 1 with each coefficient determined as described above on the experimental value of the junker repair time, and shows that the calculated value of the time and the experimental value agree fairly well. ing.

  In the above description, the jumper is taken as an example of the concrete defect, but the vibration time for repair can be determined in the same procedure for the unfilled hollow portion in the concrete mold. Even in the repair of the above-mentioned unfilled hollow part, the process of (re) vibrating the sound part of the healthy part and liquefying and repairing it is exactly the same, so the repair time is almost the same as or slightly less than the case of the jumper It is estimated that This is because less energy is required compared to reflowing and repairing the inside of the Janka aggregate.

  The vibrator 21 is provided with a recording control means such as a microcomputer for recording the above-described mathematical formulas 1 to 3 and numerical data as coefficients of the mathematical formula. Implementation of the method of the present invention is made so that the vibrator is operated only for the required vibration time by inputting the placement height, or the required vibration time is displayed on the display unit attached to the separate vibrator. It can also be provided as a vibrator suitable for the above.

  12 to 14 show a second embodiment of the present invention. In this embodiment, correction coefficients relating to the hardness and viscosity of concrete material are introduced into Formula 1 in the first embodiment.

Fig. 12 shows the use of two types of concrete materials M ₁ and M ₂ with different viscosities, and cast W / C (water-cement ratio) = 55% normal strength concrete and W / C = 35% high strength concrete. The pressure required for the height H of the upper concrete was applied, and the required vibration time for repairing the junkers was measured 45 minutes after placing. M ₁ is the reference concrete (so-called Kanto material) used in preparing the above-mentioned Table 1, and M ₂ is a highly viscous concrete material (so-called Kansai material) that reuses sea sand and crushed sand. is there. In addition, as the vibrator, an improved type in which the pendulum mass of the vibrator V ₂ of the first embodiment is 1.2 times larger is used, and as a result, the vibration time value appears to be 67% smaller than that shown in Table 1. Yes.

According to FIG. 12, in concrete material M ₁ , the vibration time at W / C = 35% is 1.1 times that of W / C = 55%, and in concrete material M ₂ , It was found that the vibration time with W / C = 35% was 1.25 times that with W / C = 55%. Therefore, it is expected that the method of the present invention can be applied to various concrete materials by introducing a correction coefficient relating to the properties of the concrete material into Equation 1.

Figure 13, corresponding to slump value of the concrete used for the vertical member, such as a building of pillars and walls (15~21cm), slump _{S L = 21cm, 18 cm,} 15 cm of the Janka repair for each The required vibration time is measured. These are obtained by experiments using concrete material M _1.

From the figure, when a reference required vibration time when the slump value _{S L = 18 cm, S L} = 21cm in its 0.88 fold, is S L ₌ 15 cm in vibration time of 1.5 to 1.6 times the required I found out.

  In addition, when the kind of concrete material is unknown, it can be determined by a known slump flow test. For example, measure the time when the slump of the test specimen piled on the slump plate vibrated with a vibrator becomes 60cm, if the time is 8-10 seconds, Kanto material, if 11-14 seconds, Kansai material, etc. It is.

  FIG. 14 is a plot of the experimental results of FIG. 13. When this is approximated by the method of least squares, the following equation is obtained.

S = s ₁ × S _L ² + s ₂ × S _L + s ₃ (Formula 3)
The coefficients of Equation 3 in this experiment were s ₁ = 0.0259, s ₂ = −1.05, and s ₃ = 11.5.

  FIG. 15 shows the result of a junker repair experiment using both the junker repair method of the first embodiment and the above-described junker detection method based on the electromagnetic dielectric method. The above-mentioned jumper detection method measures the capacitance between two terminals attached at appropriate positions on the concrete formwork, and determines that the concrete is poorly filled if the capacitance is below a reference value (100 pF in this experiment). The principle is simply explained by making use of the fact that the dense concrete part has a larger capacitance than the gap part in the jumper.

In the above experiment, when the above-mentioned junker measurement method was applied to five construction sites S ₁ and S ₂ where concrete walls with openings (windows) were respectively placed, measurement position 2 was measured at construction site S _1. and in 4, also is below the reference capacitance in a construction site S ₂ in the measurement positions 2 and 3, it is estimated that Janka has occurred. At any construction site, the elapsed time after concrete placement is 0 minutes, the concrete material used is S _L = 18 cm, W / C = 47%, and the placement height is S ₁ of the construction site. H = 0 m at measurement positions 1 to 3 and measurement positions 1 to 3 at construction site S ₂ , and H = 0.25 m at measurement positions 4 and 5 of construction site S ₁ and measurement positions 4 and 5 of construction site S ₂ It is. However, even at the measurement position where H = 0.25 m, the jumper is generated in the vicinity of the lower edge of the opening, and the substantial difference in height between the lower edge and the position where the jumper is generated is almost zero.

  As a result of calculating the required vibration time for repairing the jumper by the method of Embodiments 1 to 3, it was 20 seconds when H = 0 m and 40 seconds when H = 0.25 m. When vibration was applied for 20 seconds at the measurement position where H = 0 m, the capacitance at that location exceeded the reference value of 100 pF as shown in the figure. From this, it was found that the jumper can be sufficiently repaired with the vibration time obtained by the method of the present invention. Similarly, at the measurement position 4 where H = 0.25 m, an attempt was made to apply vibration for 40 seconds. When the vibration was applied for 20 seconds, the vibration exceeded the reference capacitance and was stopped. From this, for the junker generated below the opening, it was found that the necessary vibration time for repairing the junker should be measured using the substantial placement height from the junker occurrence point to the lower edge of the opening. .

  FIG. 16 shows a third embodiment of the present invention, in which an air hole 7 is drilled in a portion corresponding to a junker occurrence position of the concrete mold 1 prior to the excitation work. According to this aspect, when the junker occurrence location is remixed by vibration, remixing is facilitated by allowing the air present at the location to be discharged.

  The diameter of the air hole 7 is preferably 3.5 mm or less so that the concrete aggregate does not flow out. The air hole 7 should be located at the upper end of the jumper location so that air can be easily discharged. This is sufficient if the size of the jumper is normally generated (20 x 20 cm or less). It is. On the other hand, a larger jumper may be drilled at a position corresponding to an intermediate portion or a lower portion of the jumper occurrence location.

In the illustrated example, the case where no air hole is formed in the mold 1 and the case where the air hole is formed at one place corresponding to the center of the uppermost portion of the jumper generation position as shown by a solid line in FIG. As shown by the imaginary line in the figure, the relationship between the junker repair area ratio and the vibration time was tested for each of the cases where air holes were drilled at two locations corresponding to the center of the uppermost part of the jumper occurrence location, and are described in FIG. is doing. In this experiment, the vibration is applied by the vibrator V ₂ in the first embodiment after 45 minutes from the placement.

  According to the experimental results, the vibration time T until the junker repair area ratio reaches 100% is 2/3 in the case where the air hole is drilled in one place as compared with the case where the air hole is not drilled. In addition, when air holes are formed in two places, the holes are shortened to ½.

FIG. 18 shows a fourth embodiment of the present invention. For various vibrators V _{1 to} V ₄ in the first embodiment, the junker repair area ratio and vibration when vibration is applied for 90 seconds, respectively. It represents the relationship with numbers. In this figure, the junker repair area ratio is almost 100% in the frequency range of 130 to 250 Hz. At frequencies lower than this range, the junker repair area ratio does not reach 100%, which is understood to be because vibration energy is insufficient to repair the junkers as described above. Above 250 Hz, the junker repair area ratio shows a slightly decreasing trend according to experimental data. The reason is unknown, but at least experimentally, a 100% Junker repair area ratio was obtained at a frequency of 130 Hz, and energy loss could occur due to various causes at the construction site. Even so, it is sufficient to add vibration energy in the range of 130 to 250 Hz, and it is considered that energy loss is large if the vibration frequency is higher than that.

  19 to 20 show modifications of the vibrator 21 suitable for the method of the present invention.

  The vibrator 21 includes a vibrator body 22 and a processing device 23.

  The vibrator main body 22 is preferably a handy type known vibrator, and is connected to an external power source (not shown) through a power supply line 30 in the illustrated example.

  The processing device 23 has a calculation function for calculating the required vibration time for repairing the jumper using the vibrator main body 22, and for vibrating the vibrator main body for the required time based on the result of the calculation. It has a control function. These functions are realized by incorporating a computer in which the above Equations 1 to 4 and coefficient data specific to the vibrator main body 22 included in these Equations are recorded in the processing device.

  The processing device 23 has a control panel 25 formed by an information input unit 26, a vibrator main body drive button 27, and a display 29 as shown in FIG.

  The information input unit 26 includes a time information input button 26a, a height information input button 26b, and a material information input button 26c. In the illustrated example, each button is formed by a pair of arrow buttons so that numerical information appearing on the display can be increased or decreased by pressing these arrow buttons. In the example shown in the figure, the time information is the elapsed time from the completion of concrete placement, and the height information is the difference in height between the top of the concrete measured with a convex or the like and the junker restoration location (that is, the placement height of the upper concrete). In addition, slump values of concrete materials can be input as material information. However, instead of these pieces of information, other information described later may be substituted.

 In the illustrated example, the vibrator main body drive button 27 is formed of a main drive button (start button) 27a and a follow vibration button 27b. The main drive button 27a is used to vibrate the vibrator main body 22 for the required vibration time calculated from the input information, and it is generally expected that the jumper is sufficiently repaired by the vibration. However, it is not necessarily the case that the junker cannot be completely repaired due to the unevenness of the properties of the concrete in the formwork, and if it is found by hammering inspection etc., the additional vibration button 27b is pushed to complete the junka. Follow-up vibration can be applied. Reference numeral 28 denotes a follow vibration time selection button.

  The display 29 first displays the initial values of the time information, height information, and material information described above, and when the user presses each information input button 26a, 26b, 26c, the corresponding information value is displayed. When the input information is confirmed by pressing a confirmation switch (not shown) or the like, the vibration time required for the repair of the jumper may be displayed. Further, at least at the stage when the excitation work is completed, the initial value of the follow-up vibration time is displayed on the display 29. When the follow-up vibration time selection button 28 is pressed, the follow-up vibration time displayed correspondingly increases or decreases. It is formed as follows.

 The processing device 23 is integrally connected to the upper surface of the vibrator main body 22 via a fixture (not shown), but as a separate body from the vibrator main body 22, for example, the vibrator main body and an external power source The power supply line 30 may be interposed between the vibrator main body and the vibrator main body separately from the power supply line.

  The processing device 23 has a clock function and is through a control panel, and can input the time at which concrete is placed instead of the elapsed time from the concrete placement through the control panel 25. In addition, the processing device may be configured to automatically measure the elapsed time from the concrete placement time when the main drive button 27a is pressed. In the example shown in the figure, the difference in height between the top of the concrete and the repaired portion of the jumper is visually measured. However, a known measurement that automatically measures the difference in height between the two by marking them with infrared or laser. A container (not shown) may be provided in conjunction with the information input unit. The measuring instrument may be formed integrally with the processing apparatus 23 or separately.

  In the configuration shown above, when it is determined that a jumper has occurred after a certain period of time has passed since concrete placement, the above time information, height information, and material information are input to the processing device 23 via the control panel 25. Then, when the information is confirmed, the required vibration time for repairing the jumper is displayed on the display 29 of the control panel 25. Next, when the vibration part 22a at the tip of the vibrator main body 22 is brought into contact with the mold part corresponding to the place where the jumper is generated and the main drive button 27a of the processing device 23 is pressed, vibration is generated by the oscillation signal transmitted from the processing device 23. The machine main body 22 vibrates and the occurrence of the jumper is repaired by the vibration. When the required vibration time has elapsed, a stop signal is issued from the processing device 23, and the vibration of the vibrator main body 22 stops. After the stop, a vibration test is performed on the vibration location, and if the sound is normal, the junker is repaired. Add vibration.

  In the above description, the processing device 23 is configured to control the operation of the vibrator main body 22. However, the processing device 23 simply calculates the time required to repair the jumper based on the input data. It may be displayed only on the display 29 of the control panel, and the user may drive the processing device 23 according to the displayed time.

FIG. 6 is a process explanatory diagram of the jumper repair method according to the first embodiment of the present invention. FIG. 2 shows a configuration example of an experimental apparatus for obtaining data supporting the method of the present invention, in which FIG. (A) is a perspective view of the apparatus before the experiment, and (b) is a cross section of the apparatus during the experiment. FIG. It is a graph showing the experimental data which show the correlation of the vibration energy total amount to a junker generation | occurrence | production location, and the junker restoration area rate for every kind of vibrator. It is a graph showing the experimental data which show the correlation with the vibration energy total amount to a junker generation | occurrence | production location, and a junker restoration area rate for every elapsed time after placement. It is a graph showing the experimental data which show the correlation with the vibration energy total amount to a junker generation | occurrence | production location, and the junker restoration area rate for every casting height of upper concrete. It is a graph showing the correlation with the elapsed time after concrete pouring and the vibration time for junker restoration for every casting height of upper concrete. It is a graph showing the correlation between the placement height of the upper concrete and the vibration time for the junker restoration for each elapsed time after the concrete placement. It is a graph showing the relationship between the junker restoration area ratio of the concrete repaired by the method of this invention, and core compressive strength. FIG. 7 is a modified example of the first embodiment, and shows experimental values representing the relationship between the vibration time difference and the square value of the elapsed time after placement in order to formulate the experimental data of FIG. It is a figure showing the relationship between the inclination A of Formula 1 derived from FIG. 9 and its intercept B and the upper concrete height H. It is the figure which piled up the numerical formula 1 which determined the coefficient based on FIG.9 and FIG.10 on the data of the experimental value. It is a figure showing the vibration time for the junker repair for every concrete material in 2nd Embodiment of this invention method. In the said 2nd Embodiment, it is a figure showing the vibration time for every slump value of concrete material. FIG. 13 is a diagram illustrating a vibration time correction value for each slump value derived from the data of FIG. It is a figure which shows the result of the junker restoration experiment by the method which concerns on 1st and 2nd embodiment. It is a figure which shows the air hole drilling example in 3rd Embodiment of this invention method. FIG. 17 is a diagram showing the relationship between the junker repair area ratio for each number of air holes and the vibration time necessary for the jumper repair in the configuration of FIG. Is a diagram representing the Janka repair area ratio of each vibrator V ₁ ~V ₄ in the fourth embodiment of the present invention methods. It is a perspective view of one embodiment of a vibrator concerning the present invention. FIG. 20 is a diagram showing a processing device according to the vibrator of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Formwork 2 ... Concrete 3 ... Junker location 4 ... Concrete top 7 ... Air hole
11 ... Form 12 ... Same front wall 13 ... Side rear wall 14 ... Partition plate 15 ... Gravel 16 ... Pressure machine
21 ... vibrator 22 ... vibrator body 22a ... vibrating unit 23 ... processing device
25 ... Control panel 26 ... Information input part 26a ... Time information input button
26b… Height information input button 26c… Material information input button
27 ... Vibrator main body drive button 27a ... Main drive button 27b ... Additional vibration button
28 ... Additional vibration time selection button 29 ... Display 30 ... Power supply line

Claims (8)

When repairing defects such as junkers that occur during the curing period after concrete placement and before curing by oscillating the defect occurrence site, the total amount of vibration energy necessary for repairing the defect is placed in the concrete placement. According to the elapsed time t from time, a method for repairing defects that occurred during the construction of the concrete structure determined based on the data created in advance for the correlation between the amount of energy and the elapsed time ,
A concrete defect during the construction of a concrete structure, characterized in that the vibration time T required to repair a concrete defect when the vibration energy is applied at a constant rate in time is determined by the following formula 1. Repair method.
[Formula 1] T = A × t ² + B (A and B are time constants) 2. The method for repairing a concrete defect generated during construction of a concrete structure according to claim 1, wherein the correlation between the total amount of vibration energy and the elapsed time from the time of placing the concrete is plotted and recorded. . The time constant A and B, and determines the following equation 2 to equation 3 for the height H from the excitation point to the concrete crest and variables, construction of claim 1 concrete structure according A method for repairing concrete defects that occur inside.
[Formula 2] A = a ₁ × H + a ₂ (where a ₁ and a ₂ are constants relating to H)
[Formula 3] B = b ₁ × H + b ₂ (where b ₁ and b ₂ are constants relating to H) Multiplying the right side of Equation 1 by the correction coefficient S relating to the slump S _L of ready-mixed concrete, it is expressed as T = S × (A × t ² + B), and the correction coefficient S is expressed by the following Equation 4. A method for repairing a concrete defect generated during construction of a concrete structure according to claim 1 or 3,
[Formula 4] S = s ₁ × S _L ² + s ₂ × S _L + s ₃ The mold portion corresponding to Janka occurrence point of the mold that Da設the concrete, and the content to be drilled air holes 7 before concussion to any of claims 1 to 4 A method for repairing a concrete defect generated during construction of the concrete structure described. The method for repairing a concrete defect generated during construction of a concrete structure according to any one of claims 1 to 5 , wherein the frequency is 130 to 250 Hz. A vibrator for repairing a concrete defect generated during construction of a concrete structure,
A vibrator main body 22 and a processing device 23 with an arithmetic function provided with an information input unit 26,
When the time information necessary to obtain at least the elapsed time after concrete placement is input to the information input unit 26, the processing device 23 uses the vibrator main body 22 according to the elapsed time. Calculate the required vibration time to repair the jumper and configure the vibrator main body 22 to vibrate only within the calculated required vibration time ,
When the processing unit 23 inputs the height from the place of vibration to the cast concrete to the top of the concrete to the information input unit 26, the required vibration time for repairing the junkers according to the height. A vibrator characterized by being configured to calculate with correction . The processing device 23 measures the vibration time from the start of the vibrator main body, and automatically stops the vibrator main body 22 when the measured vibration time reaches the required vibration time for repairing the junker. The vibrator according to claim 7 , wherein the vibrator is configured as follows.

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