JP3511040B2 - Method for measuring compaction of fresh concrete and method for managing compaction - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a slump 0 cm hardening
Rino fresh concrete over preparative degree of compaction method of the measurement of, and a compaction management method.

[0002]

2. Description of the Related Art Fresh concrete or fresh mortar after pouring (hereinafter referred to as "fresh concrete, etc." in the present specification) causes junkers and bean boards when compaction is insufficient. It is being compacted. For example, a rod-shaped vibrator or a form-panel-mounted vibrator is generally used, and a vibrating roller is particularly used in the RCD method for dam construction. As described above, although compaction of fresh concrete etc. is performed by various methods, it is not possible to know in real time how much compaction is performed during compaction work, so the number of rolling pressure of the vibrating roller, the bar vibrator or the mold The vibration time of the vibrator attached to the frame panel or the like may be excessive or insufficient, which may result in inconsistent compaction degree and uneven quality of concrete.

As a method of knowing in real time how much the fresh concrete or the like has been compacted during compaction work, a method of hitting the outside of the form with a mallet and judging by the sound, fresh concrete or the like is used. There is a method of visually observing breathing water, and a method called RI method used for dam RCD method. This RI method embeds the radiation generating terminal in compacted fresh concrete, etc., installs a radiation measuring section on the surface of the fresh concrete, etc., and measures the radiation amount passing through the fresh concrete etc. to determine the degree of compaction. This is the method of judgment.

[0004]

However, in the method of hitting with a mallet and the method of visually observing the breathing water, the compaction degree is judged subjectively by the measurer, so that a certain degree of compaction cannot be obtained. However, there is a problem that the quality of concrete becomes uneven.

Further, the concrete used in the RCD method for dams has been kneaded firmly from the beginning such that the slump is 0 cm, and at the time of compaction, it is further compacted by rolling with a vibrating roller. Therefore, when the RI method is applied to the dam RCD method, a great amount of labor is required to embed the radioactivity generation terminal in the RCD concrete. Therefore, it is difficult to measure the compaction degree in real time while rolling the RCD concrete with the vibrating roller, and there is a problem that the quality of the concrete is likely to be non-uniform because the compaction degree is excessive or insufficient.

[0006] The present invention has St. solve the above problems, tightening its object is capable of determining the real time, and objectively degree of compaction, while the compaction work of the fresh concrete over preparative It is to provide a method for measuring the degree of compaction.

Further, another object of the present invention is to provide a compaction method for managing fresh concrete over bets can Rukoto give hardened fresh concrete over directors to a predetermined degree of compaction.

[0008]

The present invention has been made in view of the above objects, and its gist is a slump of 0 cm.
A method for measuring the compaction degree of fresh concrete of hard kneading , which comprises:
The degree of compaction and whether it is fresh concrete during compaction work.
To obtain the relationship with the elastic wave with a frequency of 20 kHz or more
In addition, even in the construction site, fresh concrete
Measure the elastic wave while performing the compaction work of the
Elastic wave measured at this construction site and
From the relationship between the compaction degree and the elastic wave, which was set aside,
Degree of compaction Gerhard concrete is determined in compaction method of measuring fresh concrete, characterized in Rukoto.

In the method for measuring the degree of compaction according to the present invention, the fresh concrete to be measured means that concrete constituent materials such as aggregate, cement, water and an admixture are not sufficiently bonded to each other and are not yet solidified. Any concrete can be used, including those that have just been mixed and kneaded in a mixer, to those that are close to hardened concrete in which the hydration reaction of cement has progressed and the concrete constituent materials are integrated .

[0010] In degree of compaction measurement method of the present invention, the <br/> The elastic wave concrete over preparative occurs, the concrete over preparative
When aggregates are compacted, the aggregates of the constituent materials, cement, water, admixture, etc. collide with each other and rub against each other, or when the concrete constituent materials harden together due to the hydration reaction of the cement. A sound wave in the ultrasonic range having a frequency of 20 kHz or higher. As a method of measuring this elastic wave, it is possible to use a sensor called a "AE sensor", which is provided with a piezoelectric element that converts mechanical vibration into an electric signal. By using the analysis system, various AE parameters such as AE COUNT, AE envelope detection (event, maximum amplitude, duration, rise time, and energy) can be obtained in real time, and the degree of compaction can be determined. It can be easily judged.

[0011] In the compaction degree measuring method of the present invention, first, either affixed to AE sensor in a mold outer surface, or placing the AE sensor on the front surface of the fresh concrete over and.
When placing the AE sensor on the front surface of the fresh concrete over preparative it may be disposed directly on the surface of the concrete over bets,
Alternatively waves conductive good member, for example, a metallic plate such as a steel plate by disposing the front surface of the concrete over preparative may be disposed AE sensor on the metal plate. Furthermore, the RCD of the dam
In the construction method, the vibrating roller and the steel plate may be connected by a cord, and the AE sensor may be arranged on the steel plate.

After the AE sensor is arranged, the elastic wave is measured while compacting the concrete. Fresh co <br/> Nkuri over DOO according compacted tighten and deflated are kneaded, gradually increasing Mitsumi of. If Such densely real is go increases, <br/> in the fresh concrete over DOO is easier acoustic wave of a high frequency is transmitted, AE COUNT of the measured acoustic waves, various such AE envelope detection AE parameters, that is, AE characteristics also change. Therefore, in advance,
AE such as predominant frequency of elastic wave, AE COUNT, AE envelope detection
And characteristics can be determined by previously obtained relation between degree of compaction of fresh concrete over preparative, the degree of compaction of fresh co <br/> Nkuri over preparative construction construction site in real time.

Another subject of the present invention is that the slump is 0 cm.
Is a method for controlling the compaction of freshly kneaded fresh concrete , wherein the compaction degree of the fresh concrete is set in advance.
And from the fresh concrete during compaction work
The relationship with elastic waves with a frequency of 20 kHz or more
Before when fresh concrete is compacted from the clerk
Construction of construction by obtaining frequency distribution or AE characteristics of elastic wave
Compacting fresh concrete on-site
Measure the elastic wave while doing it, and at this construction site
The elastic wave in the wave is the frequency of the elastic wave previously obtained.
A method for controlling compaction of fresh concrete is characterized in that the fresh concrete is repeatedly compacted until a distribution or an AE characteristic is reached.

In the compaction management method of the present invention, the same means and the same procedure as the method for measuring the degree of compaction described above are used.
Bullets when fresh concrete is previously compacted
Obtain the frequency distribution or AE characteristics of the sex wave, and
Even in compaction work in the field, this pre-determined elasticity is required.
Repeated compaction of fresh concrete until a wave frequency distribution or AE characteristic is reached allows the construction of a fully compacted and high quality concrete structure.

[0015]

In the fresh concrete compaction degree measuring method and compaction managing method of the present invention, the fresh concrete
When the shoe is compacted, its constituent material, aggregate,
Cement, water, admixture, etc. collide with each other and rub against each other, and the hydration reaction of cement causes the concrete constituent materials to harden together, and the elastic waves generated are measured to determine the degree of compaction.

[0016]

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0017] Incidentally, embodiments described below, which the fresh concrete over preparative compaction measurement methods and compaction management method of the present invention is applied to compaction measurement of fresh concrete used in the RCD method of dam Is.

[0018]

[Example 1] RCD having a unit water amount per unit volume of concrete (hereinafter referred to as "W") of 89 kg / m3
A sample of concrete for use was prepared, and an elastic wave at that time was measured by an AE sensor (manufactured by Japan Physical Acoustics Co., Ltd.) while the sample was compacted by a VC tester. Here, the VC tester is developed for measuring the consistency of RCD concrete, and is provided with a cylinder for packing the RCD concrete and a vibrating table for vibrating the cylinder. Is. The VC value measured by this VC tester is determined by the time (in seconds) until the RCD concrete is compacted and solidified by placing the cylinder on the vibration table after filling the cylinder with the RCD concrete. Given. The completion of compaction is determined by the mortar breathing on the surface of the RCD concrete.

The measured results are shown in FIGS. 1 and 2. Figure 1
Shows the frequency frequency of 10 seconds after the compaction was started by vibrating the vibrating table of the VC tester, and FIG. 2 shows the frequency frequency of 10 seconds from 50 seconds to 60 seconds after the compaction was started. Is shown.

Start compaction 10 as shown in FIG.
Most of the elastic waves are measured in the range of 1 MHz or less for a second, but as shown in FIG.
In 10 seconds of up to 60 seconds, as compared with FIG. 1, many elastic waves of 1 MHz or more are also measured. Therefore, fresh concrete over DOO in accordance solidifies tightened, high elasticity wave frequencies it can be seen that easily transmitted to the concrete surface. Therefore, at the actual construction work site, while performing the compaction work, the elastic wave is measured by the AE sensor, and further, by the analysis system equipped with the arithmetic processing device, as shown in FIG. 1 and FIG. If the frequency distribution is obtained, the compaction degree can be determined in real time.

[0021]

Example 2 Next, RC of W = 84, 89, 91 kg / m3
A sample of concrete for D was prepared, and while the sample was compacted by a VC tester, the acoustic wave at that time was measured by an AE sensor, and the VC value was also visually measured.

3 (a) to 3 (d), an AE sensor measures elastic waves from the start of compaction to 100 seconds while compacting a sample of RCD concrete with W = 84 kg / m3 by a VC tester. 3 (a) shows the measurement frequency of elastic waves equal to or higher than a predetermined threshold value, that is, AE COUNT every 2 seconds.
FIG. 3B shows the measurement result of FIG. 3A integrated over the measurement time. Further, FIG. 3 (c) shows AE ENERGY (AE energy) every 2 seconds, and FIG. 3 (d) is an integration of the measurement results of FIG. 3 (c) over the measurement time.
From the graph in Fig. 3, the compaction time when the AE COUNT rapidly increases is 91 seconds and the compaction time when the AE ENERGY rapidly increases is 92.
You can see that the seconds are. The VC value of this sample is 9
It was 0 seconds.

4 (a) to 4 (d) show R of W = 89 Kg / m3
It is the measured value which experimented the sample of the concrete for CD like FIG.3 (a)-(d), of which FIG.4 (a) is AE C.
OUNT is shown every 2 seconds, and FIG. 4 (b) is shown in FIG.
The measurement result of (a) is integrated over the measurement time. Further, FIG. 4 (c) shows AE ENERGY every 2 seconds, and FIG. 4 (d) shows the measurement result of FIG. 4 (c) integrated over the measurement time. From the graph of this Figure 4, AE COUN
It can be seen that the compaction time for T and AE ENERGY increases rapidly is 62 seconds. The VC value of this sample was 60 seconds.

Further, in FIGS. 5A to 5D, W = 91 kg / m
While compressing the RCD concrete sample of No. 3 with a VC tester, elastic waves from the start of compaction until 62 seconds have elapsed are measured values by the AE sensor, and FIG. 5 (a) shows AE COUNT of 2 FIG. 5B shows the measurement result of FIG. 5A integrated by the measurement time. Further, FIG. 5 (c) shows AE ENERGY every 2 seconds, and FIG. 5 (d) shows FIG. 5 (c).
It is the result of integration of the measurement result of 1. This Figure 5
The graph shows that the AE COUNT rapidly increases and the compaction time is 43
It can be seen that the compaction time at which the AE ENERGY increases rapidly is 42 seconds. The VC value of this sample was 40 seconds.

FIG. 6 shows the compaction time and AE obtained from FIGS. 3 to 5 at which the AE COUNT of each sample rapidly increases.
This is a graph showing the relationship between the VC value and the compaction time when ENERGY rapidly increases.

From FIG. 6, it can be seen that, in the same sample, the compaction time in which AE COUNT rapidly increases and the compaction time in which AE ENERGY rapidly increases almost coincide with the VC value.
Therefore, even at the actual construction work site, the elastic wave is measured by the AE sensor while performing the compaction work, and further, by the analysis system including the arithmetic processing device, as shown in FIG.
As shown in FIG. 5, if the compaction time in which AE COUNT rapidly increases and the compaction time in which AE ENERGY rapidly increases, the compaction degree can be determined in real time.

[0027]

The fresh concrete over preparative tightening solid <br/> Me measuring method of the present invention, in advance, a clamping <br/> compacted degree of fresh concrete over preparative, from fresh concrete over preparative during compaction operations
Dominant frequency of the acoustic wave that occurs, AE COUNT, by keeping obtained relation between AE characteristics such as AE envelope detection, to measure the elastic wave Fresh concrete over preparative during compaction operations,
Furthermore, this measurement, by obtaining the AE characteristics analyzed by the analysis system having an arithmetic processing device, it is possible to determine the degree of compaction of fresh concrete over preparative real-time construction construction site.

[0028] In compaction management method of the present invention, pre
Therefore, the compaction degree of fresh concrete and compaction work
Frequency generated from fresh concrete inside 20k
The relationship with elastic waves above Hz is obtained, and from this relationship
Frequency of elastic waves when compacted concrete
Find the distribution or AE characteristics and put it on the construction site.
Even if you do not compact the fresh concrete
Elastic wave is measured from the
Is the elastic wave frequency distribution or AE characteristic
Repeated compaction of fresh concrete until it reaches its properties allows the construction of a fully compacted and high quality concrete structure.

[Brief description of drawings]

FIG. 1 is a graph showing the frequency frequency of elastic waves measured in Example 1 for 10 seconds after the start of compaction.

FIG. 2 is 50 to 60 after the start of compaction measured in Example 1.
It is a graph which showed the frequency frequency of the elastic wave for 10 seconds of a second.

FIG. 3 (a) is W = 84 Kg / m measured in Example 2.
3 shows the AE COUNT of the RCD concrete sample of 3 every 2 seconds, (b) is the integration of the measurement results of (a) over the measurement time, and (c) is the AE ENERGY of 2
It is shown for each second, and (d) is obtained by integrating the measurement result of (c) with the measurement time.

FIG. 4 (a) is W = 89 Kg / m measured in Example 2.
3 shows the AE COUNT of the RCD concrete sample of 3 every 2 seconds, (b) is the integration of the measurement results of (a) over the measurement time, and (c) is the AE ENERGY of 2
It is shown for each second, and (d) is obtained by integrating the measurement result of (c) with the measurement time.

FIG. 5 (a) is W = 91 Kg / m measured in Example 2.
3 shows the AE COUNT of the RCD concrete sample of 3 every 2 seconds, (b) is the integration of the measurement results of (a) over the measurement time, and (c) is the AE ENERGY of 2
It is shown for each second, and (d) is obtained by integrating the measurement result of (c) with the measurement time.

FIG. 6 is a graph showing the relationship between the VC value and the compaction time in which the AE COUNT of each sample sharply increases and the compaction time of AE ENERGY sharply increases in Example 2.

─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-56-652 (JP, A) JP-A-5-93715 (JP, A) Actual development Sho-60-150261 (JP, U) JP-B-51- 10604 (JP, B1) (58) Fields investigated (Int.Cl. ⁷ , DB name) E04G 21/06 G01N 29/02

Claims (2)

(57) [Claims] 1. A method for measuring the degree of compaction of fresh concrete with a slump of 0 cm, which comprises :
Compaction degree of the fresh concrete and compaction work
Frequency generated from fresh concrete inside 20k
The relationship with the elastic wave of Hz or more is sought, and the construction site
Even in this case, the compaction work of fresh concrete should be performed.
While measuring the elastic wave,
And the elastic wave measured by
Compaction of fresh concrete from the relationship with elastic waves
Compaction measurement method of fresh concrete, characterized in Rukoto because degree is determined. 2. A method for controlling compaction of fresh concrete with a slump of 0 cm , which comprises:
The degree of compaction of ash concrete and the
Frequency of 20 kHz or more generated from ash concrete
Of the elastic wave of the
Frequency distribution of elastic waves when the REIT is compacted or
Seeking AE characteristics, fresh co
The elastic wave is measured while compacting the cleats.
And obtain the elastic wave at this construction site in advance.
A method for managing compaction of fresh concrete, characterized in that the fresh concrete is repeatedly compacted until the frequency distribution or the AE characteristic of the elastic wave is reached.