JP7097015B2 - How to determine the degree of compaction of concrete - Google Patents

How to determine the degree of compaction of concrete Download PDF

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JP7097015B2
JP7097015B2 JP2018029751A JP2018029751A JP7097015B2 JP 7097015 B2 JP7097015 B2 JP 7097015B2 JP 2018029751 A JP2018029751 A JP 2018029751A JP 2018029751 A JP2018029751 A JP 2018029751A JP 7097015 B2 JP7097015 B2 JP 7097015B2
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修治 松本
吾郎 坂井
修司 柳井
学 橋本
浩平 水野
和英 倉田
昇 坂田
惠介 井上
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Kajima Corp
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Description

本発明は、コンクリートの締固め度判定方法、及び、コンクリートの締固め度判定装置に関する。 The present invention relates to a method for determining the degree of compaction of concrete and a device for determining the degree of compaction of concrete.

コンクリートを打設する際、型枠内に充填されたコンクリートが確実に充填されているかどうか、及び、確実に締め固められているかどうかについて、従来様々な方法で確認している。確実に充填されているかどうかについては、例えば、型枠として透明なアクリル製のものを使用したり、埋設型の充填検知センサーを用いたりしている。また、確実に締め固められているかどうかについては、例えば、バイブレータによる振動で締め固めたり、締固めの作業が不要な高流動コンクリートを用いたりしている。 When placing concrete, it has been confirmed by various methods in the past whether or not the concrete filled in the formwork is surely filled and whether or not it is surely compacted. As for whether or not the formwork is surely filled, for example, a transparent acrylic formwork is used, or a buried type filling detection sensor is used. Further, as to whether or not the concrete is surely compacted, for example, compaction is performed by vibration by a vibrator, or high-fluidity concrete that does not require compaction work is used.

他方、地盤表面を締め固める要請がある分野においては、ガンマ線や中性子線を地盤の表層に照射し、地盤を透過した放射線を計測して地盤の状態を知る技術が用いられている（例えば特許文献１参照）。 On the other hand, in the field where there is a request to compact the ground surface, a technique of irradiating the surface layer of the ground with gamma rays or neutron rays and measuring the radiation transmitted through the ground to know the state of the ground is used (for example, patent documents). 1).

特開平８－７４２３８号公報Japanese Unexamined Patent Publication No. 8-74238

上記従来の方法では、充填性の判断において、透明な型枠では視認できる深さに限度があるし、充填検知センサーをコンクリート躯体に埋め込むことになるのは構造物としての品質を損なう虞がある。また、締固めの善し悪しは作業者の技能に依るところが大きく、判断も定性的であり品質にばらつきが生じる傾向がある。高流動コンクリートは高価であるし、施工対象によっては必ずしも適性でない場合もある。 In the above-mentioned conventional method, there is a limit to the depth that can be visually recognized with a transparent formwork in determining the filling property, and embedding the filling detection sensor in the concrete skeleton may impair the quality of the structure. .. In addition, the quality of compaction largely depends on the skill of the worker, the judgment is qualitative, and the quality tends to vary. High-fluidity concrete is expensive and may not always be suitable depending on the construction target.

そこで本発明は、通常の流動性を有するコンクリートであっても所望の締固め度合いが達成されたことを確認することができる、コンクリートの締固め度判定方法を提供することを目的とする。また、その判定方法に用いることができるコンクリートの締固め度判定装置を提供することを目的とする。 Therefore, an object of the present invention is to provide a method for determining the degree of compaction of concrete, which can confirm that a desired degree of compaction has been achieved even for concrete having normal fluidity. Another object of the present invention is to provide a concrete compaction degree determination device that can be used in the determination method.

本発明は、型枠の中に充填されたコンクリートに放射線を照射し、コンクリートを通過した放射線を型枠の外に設置したＲＩ計測器により計測する計測工程を有し、計測工程では、コンクリートを締め固めながら又は締め固めた後に、放射線の計測を連続的又は離散的に行い、ＲＩ計測器が示す計測値が所定の値領域に収束した時点、又は、ＲＩ計測器が示す計測値が所定の値領域内に達した時点を締固め完了と判断する、コンクリートの締固め度判定方法を提供する。 The present invention has a measurement process of irradiating concrete filled in a formwork with radiation and measuring the radiation passing through the formwork with an RI measuring instrument installed outside the formwork. In the measurement process, concrete is used. Radiation measurement is performed continuously or discretely during or after compaction, and the measured value indicated by the RI measuring instrument converges to a predetermined value region, or the measured value indicated by the RI measuring instrument is predetermined. Provided is a method for determining the degree of compaction of concrete, which determines that compaction is completed when the value reaches within the value range.

この判定方法では、コンクリートを通過する放射線をＲＩ計測器によって計測することでコンクリートの密度を算出することができ、その値からコンクリートの締固め度合いを知ることができる。従って、通常の流動性を有するコンクリートであっても所望の締固め度合いが達成されたことを確認することができる。 In this determination method, the density of concrete can be calculated by measuring the radiation passing through the concrete with an RI measuring instrument, and the degree of compaction of the concrete can be known from the value. Therefore, it can be confirmed that the desired degree of compaction has been achieved even with concrete having normal fluidity.

なお、本発明における「締固め」は、コンクリートを型枠内に行き渡らせる「充填」の意味と、行き渡ったコンクリートの密度を高める狭義の「締固め」の意味を含むものとする。 In addition, "compacting" in the present invention includes the meaning of "filling" in which concrete is distributed in the formwork and the meaning of "compacting" in a narrow sense to increase the density of the distributed concrete.

上記所定の値領域は、コンクリートの配合から推定される締固め後の密度に基づく理論値領域であってもよい。この場合、ＲＩ機器による計測を離散的として計測回数が少ない場合であっても、計測結果がその理論値領域内に収まっていれば、コンクリートが所望の締固め度合いに達したと認めることができる。 The predetermined value region may be a theoretical value region based on the density after compaction estimated from the concrete composition. In this case, even if the measurement by the RI device is discrete and the number of measurements is small, if the measurement result is within the theoretical value range, it can be recognized that the concrete has reached the desired compaction degree. ..

本発明では、ＲＩ計測器による計測を型枠の外における複数の箇所で行ってもよい。この場合、主にコンクリートの充填性を確認することができる。すなわち、一箇所でのみ計測した場合は、計測値が所定の値領域に収束する等して締固めが完了したことを確認することができるが、仮に、他の箇所で計測した場合に計測値が別の値領域に収束した場合、充填性にばらつきがあることが推定される。 In the present invention, the measurement by the RI measuring instrument may be performed at a plurality of places outside the mold. In this case, the filling property of concrete can be mainly confirmed. That is, if the measurement is performed at only one location, it can be confirmed that the compaction is completed by converging the measured value to a predetermined value region, but if the measurement is performed at another location, the measured value is measured. If is converged to another value region, it is presumed that the filling property varies.

本発明において、ＲＩ計測器は散乱型又は透過型のいずれの計測器であってもよい。コンクリートの施工態様に応じて、両者を使い分けることができる。 In the present invention, the RI measuring instrument may be either a scattering type or a transmissive type measuring instrument. Both can be used properly according to the concrete construction mode.

本発明は、コンクリートは、鉄筋の周囲に充填されたものであり、計測工程では、コンクリートのうち型枠と鉄筋との間の領域に存在するコンクリートを対象としてもよい。当該領域は、鉄筋コンクリート構造物において「かぶり」と呼ばれる部分である。 In the present invention, the concrete is filled around the reinforcing bar, and the measuring process may target the concrete existing in the region between the formwork and the reinforcing bar in the concrete. This area is the part called "fog" in the reinforced concrete structure.

また、本発明は、型枠の中に充填されたコンクリートに放射線を照射する線源部と、コンクリートを通過した放射線を型枠の外で計測する受信部と、を備えるコンクリートの締固め度判定装置を提供する。 Further, the present invention determines the degree of compaction of concrete including a radiation source portion that irradiates the concrete filled in the formwork with radiation and a receiving portion that measures the radiation passing through the concrete outside the formwork. Provide the device.

本発明によれば、通常の流動性を有するコンクリートであっても所望の締固め度合いが達成されたことを確認することができる、コンクリートの締固め度判定方法を提供することができる。 According to the present invention, it is possible to provide a method for determining the degree of compaction of concrete, which can confirm that a desired degree of compaction has been achieved even for concrete having normal fluidity.

本実施形態を適用するコンクリート及び型枠を示した平面図である。It is a top view which showed the concrete and the formwork to which this embodiment is applied. 放射線のカウント数の経時変化を示したグラフである。It is a graph which showed the time-dependent change of the count number of radiation. 締固め前後のカウント数の変化を示すグラフである。It is a graph which shows the change of the count number before and after compaction.

以下、本発明の好適な実施形態について、図面を参照しながら詳細に説明する。なお、各図において同一部分又は相当部分には同一符号を付し、重複する説明は省略する。 Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. In each figure, the same parts or corresponding parts are designated by the same reference numerals, and duplicate description will be omitted.

本実施形態のコンクリートの締固め度判定方法は、型枠内に打設したコンクリートを対象としてその密度を測定し、その結果から締固めの程度を判断するものである。 In the method for determining the degree of compaction of concrete in the present embodiment, the density of concrete placed in a formwork is measured, and the degree of compaction is determined from the result.

図１は、本実施形態を適用するコンクリート３及び型枠１を示した平面図である。本実施形態の実施に際しては、図１に示されているとおり、上部が開放された直方体の型枠１内にコンクリート３を流し込む。ここで用いるコンクリートは、例えばスランプが８～１２ｃｍ程度の流動性を有するものである。型枠１がアクリル板のように透明な材料からなっていると、型枠１内に極端な未充填部分が生じていないかどうかを目視確認することができるので好ましい。 FIG. 1 is a plan view showing a concrete 3 and a formwork 1 to which the present embodiment is applied. In carrying out this embodiment, as shown in FIG. 1, concrete 3 is poured into a rectangular parallelepiped formwork 1 having an open upper portion. In the concrete used here, for example, the slump has a fluidity of about 8 to 12 cm. It is preferable that the mold 1 is made of a transparent material such as an acrylic plate because it is possible to visually confirm whether or not an extremely unfilled portion is generated in the mold 1.

次に、型枠１の外部から、型枠１に対してＲＩ計測器（コンクリートの締固め度判定装置）５をあてがう。ＲＩ計測器５をあてがう高さ位置としては、床又は地面からの影響を小さくするために、床又は地面から幾分の距離をおくことが好ましい。なお、図１では型枠１に接するようにＲＩ計測器５をあてがっているが、コンクリートの測定深さの調整のために、型枠１とＲＩ計測器５との間に別の板を挟み込む等して互いの距離を調整してもよい。 Next, the RI measuring instrument (concrete compaction degree determination device) 5 is applied to the formwork 1 from the outside of the formwork 1. The height position to which the RI measuring instrument 5 is applied is preferably a distance from the floor or the ground in order to reduce the influence from the floor or the ground. In FIG. 1, the RI measuring instrument 5 is applied so as to be in contact with the formwork 1, but another plate is sandwiched between the formwork 1 and the RI measuring instrument 5 in order to adjust the measurement depth of concrete. The distance between them may be adjusted by equalizing.

ＲＩ計測器５は線源部５ａと受信部５ｂとを内蔵している。このＲＩ計測器５は、線源部５ａからコンクリート３に向けて照射した放射線のうち、コンクリート３内を散乱及び通過して戻ってきた放射線を受信部５ｂでカウントする、いわゆる散乱型の計測器である。線源としては、コバルト６０（６０Ｃｏ）やセシウム１３７（１３７Ｃｓ）を好適に使用することができる。散乱型のＲＩ計測器５としては、セシウム１３７を使用することが特に好ましい。ＲＩ計測器５としては市販されている装置を用いることができる。 The RI measuring instrument 5 has a built-in radiation source unit 5a and a receiving unit 5b. This RI measuring instrument 5 is a so-called scattering type measuring instrument in which, among the radiation emitted from the radiation source portion 5a toward the concrete 3, the radiation scattered and passed through the concrete 3 and returned is counted by the receiving portion 5b. Is. As the radioactive source, cobalt-60 ( 60 Co) or cesium-137 ( 137 Cs) can be preferably used. As the scattering type RI measuring instrument 5, it is particularly preferable to use cesium-137. As the RI measuring instrument 5, a commercially available device can be used.

次にコンクリート３を締め固めるため、コンクリート３の任意の箇所に棒状バイブレータ７を突き刺し、振動を与える。振動によってコンクリートを締め固めながら、ＲＩ計測器５を稼働させて放射線のカウントを連続的に続ける（計測工程）。コンクリート３に振動を与えることで、型枠１内で充填度合いが高まっていくとともに、コンクリート３が締め固まってゆく。 Next, in order to compact the concrete 3, a rod-shaped vibrator 7 is pierced into an arbitrary portion of the concrete 3 to give vibration. While compacting the concrete by vibration, the RI measuring instrument 5 is operated to continuously count the radiation (measurement process). By giving vibration to the concrete 3, the filling degree in the formwork 1 increases, and the concrete 3 is compacted.

図２に、実測値の例として、コンクリート３の締固め前（「Ａ」の時間帯）、締固め中（「Ｂ」の時間帯）、締固め後（「Ｃ」の時間帯）における放射線のカウント数の経時変化を示した。締固め前では、時間ごとのカウント数が概ね７５０～８７０の値領域に収まっている。締固め中は、時間ごとのカウント数が降下している。締固め後では、時間ごとのカウント数が概ね６７０～７８０の値領域に収まっている。 In FIG. 2, as an example of the measured values, the radiation before compaction (“A” time zone), during compaction (“B” time zone), and after compaction (“C” time zone) of the concrete 3 as an example. The time course of the count number is shown. Before compaction, the number of counts per hour is generally within the value range of 750 to 870. During compaction, the hourly count is dropping. After compaction, the number of counts per hour is generally within the value range of 670 to 780.

図２から、放射線のカウント数は、コンクリート３の密度が変化しない状態でも一定の値領域内にばらついていることが分かる。また、締固めが進んでいる最中はコンクリート３の密度の高まりに応じてカウント数が小さくなってゆき、次第に、締固め前にカウント数がばらついていた値領域よりも小さい値領域においてカウント数がばらつくようになる。すなわち、カウント数が所定の値領域に収束することを以って、締固めが完了したことを判断することができる。 From FIG. 2, it can be seen that the radiation counts vary within a certain value region even when the density of the concrete 3 does not change. Further, during the compaction, the count number becomes smaller as the density of the concrete 3 increases, and the count number gradually decreases in the value region smaller than the value region in which the count number varies before the compaction. Will be scattered. That is, it can be determined that the compaction is completed when the count number converges to a predetermined value region.

なお、放射線のカウント数とコンクリートの密度との間には、以下の関係が成立しており、放射線のカウント数から密度を算出することができる。
（Ａ）散乱型のＲＩ計測
線源部と受信部が同位置にあり、線源部から放出された放射線のうち、コンクリートと相互作用して散乱し、受信部に到達した放射線をカウントすることによって、コンクリートの密度を測定することができる。コンクリートの密度が大きいほど、放射線とコンクリートを構成する物質中の軌道電子との相互作用が起こりやすくなり、散乱の繰返しによって放射線のエネルギーが減少するため、放射線のカウント数が少なくなる。
（Ｂ）透過型のＲＩ計測
線源部と受信部との距離が２～１５ｃｍであり、コンクリート中に配置した線源部から放出された放射線のうち、コンクリートを透過して受信部に到達する放射線をカウントすることによって、コンクリートの密度を測定することができる。散乱型と同様に、コンクリートの密度が大きいほど、放射線とコンクリートを構成する物質中の軌道電子との相互作用が起こりやすくなり、受信部に到達する放射線が少なくなる。 The following relationship is established between the number of radiation counts and the density of concrete, and the density can be calculated from the number of radiation counts.
(A) Scattering type RI measurement The radiation source and receiver are located at the same position, and among the radiation emitted from the radiation source, the radiation that interacts with concrete and scatters and reaches the receiver is counted. Allows you to measure the density of concrete. The higher the density of concrete, the easier it is for the radiation to interact with the orbital electrons in the material that makes up the concrete, and the energy of the radiation decreases due to repeated scattering, so the number of radiation counts decreases.
(B) Transmission-type RI measurement The distance between the radiation source and the receiver is 2 to 15 cm, and of the radiation emitted from the radiation source placed in the concrete, the radiation passes through the concrete and reaches the receiver. By counting the radiation, the density of concrete can be measured. As with the scattered type, the higher the density of concrete, the easier it is for the radiation to interact with the orbital electrons in the material that makes up the concrete, and the less radiation reaches the receiver.

以上のとおり、本実施形態の判定方法では、コンクリートを通過する放射線をＲＩ計測器によって計測することでコンクリートの密度を算出することができ、その値からコンクリートの締固め度合いを知ることができる。従って、スランプが８～１２ｃｍ程度の通常の流動性を有するコンクリートであっても、所望の締固め度合いが達成されたことを確認することができ、特に、初期欠陥の発生を防止することができる。また、本実施形態の判定方法には、埋設型の充填検知センサーをコンクリート中に埋め込む必要がないという利点もある。 As described above, in the determination method of the present embodiment, the density of concrete can be calculated by measuring the radiation passing through the concrete with an RI measuring instrument, and the degree of compaction of concrete can be known from the value. Therefore, even if the slump is concrete having a normal fluidity of about 8 to 12 cm, it can be confirmed that the desired degree of compaction has been achieved, and in particular, the occurrence of initial defects can be prevented. .. Further, the determination method of the present embodiment has an advantage that it is not necessary to embed the buried filling detection sensor in the concrete.

締固めが完了したことを判断する別の方法として、コンクリート３の配合からあらかじめ締固め後の理論密度を推定しておき、放射線のカウント数に基づいて導かれる密度がその理論密度に達したときを締固めの完了時と判断することもできる。この場合、必ずしも図２の「Ｂ」の時間帯に放射線をカウントする必要はなく、カウントする頻度は例えば数秒～十数秒おき、又は２０秒おきのように離散的な計測頻度でよい。また、締固めが完了したと思われる時点で一回のみカウントすることでもよい。理論密度を用いたこの判定方法であると、ＲＩ計測器５による計測回数が少ない場合であっても、計測結果が所定の理論値領域内に収まっていれば、コンクリート３が所望の締固め度合いに達したと認めることができる。 As another method of determining that compaction is completed, the theoretical density after compaction is estimated in advance from the composition of concrete 3, and when the density derived based on the radiation count reaches the theoretical density. Can also be determined when compaction is complete. In this case, it is not always necessary to count the radiation in the time zone "B" in FIG. 2, and the frequency of counting may be a discrete measurement frequency such as every few seconds to a dozen seconds or every 20 seconds. In addition, it may be counted only once when the compaction seems to be completed. In this determination method using the theoretical density, even when the number of measurements by the RI measuring instrument 5 is small, if the measurement result is within a predetermined theoretical value region, the concrete 3 has a desired degree of compaction. Can be admitted to have reached.

また、本実施形態の判定方法を、型枠１の外における複数の箇所で行うことで、コンクリート３の充填性をより良く確認することができる。すなわち、一箇所でのみ計測した場合は、上記のとおり計測値が所定の値領域に収束する等して締固めが完了したことを確認することができるが、仮に、他の箇所で計測した場合に計測値が別の値領域に収束した場合、型枠１内でのコンクリート３の充填性にばらつきがあることが推定される。従って、複数の計測箇所において同様の計測結果が得られることをもって、コンクリート３が一様に充填されていることを確認することができる。なお、このように複数箇所で計測を行う場合は、豆板等の初期欠陥が予想される部分や、コンクリートの充填が難しいと考えられる高密配筋領域を対象とすることが好ましい。 Further, by performing the determination method of the present embodiment at a plurality of places outside the formwork 1, the filling property of the concrete 3 can be confirmed better. That is, when the measurement is performed at only one place, it can be confirmed that the compaction is completed by converging the measured value to a predetermined value region as described above, but if the measurement is performed at another place. When the measured value converges to another value region, it is presumed that the filling property of the concrete 3 in the formwork 1 varies. Therefore, it can be confirmed that the concrete 3 is uniformly filled by obtaining the same measurement results at a plurality of measurement points. When measuring at a plurality of locations in this way, it is preferable to target a portion such as a bean plate where initial defects are expected, or a highly densely arranged bar region where it is considered difficult to fill concrete.

本実施形態の判定方法は、鉄筋コンクリート構造物における「かぶり」部分に対して適用することができる。ここで「かぶり」部分とは、コンクリートのうち型枠と鉄筋との間の領域をいう。かぶりの厚さは通常３～１０ｃｍ程度であり、コンクリートが充填されにくい傾向がある。従って、本実施形態の判定方法の適用対象として好適である。 The determination method of the present embodiment can be applied to a "fog" portion in a reinforced concrete structure. Here, the "cover" portion refers to the area of concrete between the formwork and the reinforcing bar. The thickness of the cover is usually about 3 to 10 cm, and concrete tends to be difficult to fill. Therefore, it is suitable as an application target of the determination method of this embodiment.

以上、本発明の好適な実施形態について説明したが、本発明は上記実施形態に何ら限定されるものではない。例えば、コンクリートのスランプの程度、型枠の形状、バイブレータの形状等は上記のものに限定されない。コンクリートは高流動コンクリートであってもよい。また、上記実施形態では散乱型のＲＩ計測器を用いる例を示したが、透過型のＲＩ計測器を用いてもよい。この場合、線源部をコンクリートに突き刺し、型枠外に設置した受信部で放射線を計測する。計測後は線源部をコンクリートから抜く。透過型のＲＩ計測器を用いる場合は、線源はコバルト６０であることが好ましい。 Although the preferred embodiment of the present invention has been described above, the present invention is not limited to the above embodiment. For example, the degree of concrete slump, the shape of the formwork, the shape of the vibrator, etc. are not limited to the above. The concrete may be high fluidity concrete. Further, although the example in which the scattering type RI measuring instrument is used is shown in the above embodiment, a transmission type RI measuring instrument may be used. In this case, the radiation source is pierced into concrete, and the radiation is measured by the receiving unit installed outside the mold. After the measurement, remove the radiation source from the concrete. When a transmission type RI measuring instrument is used, the radiation source is preferably cobalt-60.

以下、実験例を挙げて本発明の内容をより具体的に説明する。なお、本発明は下記実験例に限定されるものではない。 Hereinafter, the contents of the present invention will be described more specifically with reference to experimental examples. The present invention is not limited to the following experimental examples.

（使用材料・練混ぜ）
表１に示した材料を用いて、表２に示したスランプ１２ｃｍのモルタル及びコンクリートを調製した。ここで、粗骨材量を０ｋｇ／ｍ３としたモルタルの配合を基準とし、このモルタルに対して粗骨材を投入し練り混ぜ、単位粗骨材量５０％、１００％、１５０％の配合とした。ここで「％」表示の値は、粗骨材量の相対割合を示している。また、混和剤については、「ＡＤ１」をセメントの重量に対して１．２％の重量で添加し、「ＡＤ２」をセメントの重量に対して０．３％の重量で添加した。 (Materials used / mixing)
Using the materials shown in Table 1, the mortar and concrete of slump 12 cm shown in Table 2 were prepared. Here, based on the blending of the mortar with the coarse aggregate amount of 0 kg / m 3 , the coarse aggregate is added to the mortar and kneaded, and the unit coarse aggregate amounts of 50%, 100%, and 150% are blended. And said. Here, the value indicated by "%" indicates the relative ratio of the amount of coarse aggregate. As for the admixture, "AD1" was added in a weight of 1.2% with respect to the weight of the cement, and "AD2" was added in a weight of 0.3% with respect to the weight of the cement.

練混ぜは、粗骨材量を０ｋｇ／ｍ３としたモルタルについて、材料を投入して３０秒間練り混ぜ、次いでかき落とし、更に６０秒間練り混ぜ、次いで排出した。粗骨材量５０％、１００％、１５０％の配合については、それぞれモルタルに対して所定量の粗骨材を投入し、６０秒練り混ぜた。なお、練量は１００Ｌとした。

Figure 0007097015000001

Figure 0007097015000002
 For kneading, the material was added to the mortar having a coarse aggregate amount of 0 kg / m3 , kneaded for 30 seconds, then scraped off, kneaded for another 60 seconds, and then discharged. For the blending of the coarse aggregate amounts of 50%, 100%, and 150%, a predetermined amount of coarse aggregate was added to the mortar, and the mixture was kneaded for 60 seconds. The kneading amount was 100 L.
Figure 0007097015000001
Figure 0007097015000002

他方、表３に示した材料を用いて、表４に示したスランプフロー４３ｃｍの高流動コンクリートを調製した。混和剤については、「ＳＰ」をセメントの重量に対して０．８％の重量で添加し、「ＡＤ２」をセメントの重量に対して０．６％の重量で添加した。練混ぜは、材料を投入して３０秒間練り混ぜ、次いでかき落とし、更に９０秒間練り混ぜ、５分間静置し、その後３０秒間練り混ぜ、次いで排出した。なお、練量は８０Ｌとした。

Figure 0007097015000003

Figure 0007097015000004
 On the other hand, using the materials shown in Table 3, high-fluidity concrete having a slump flow of 43 cm shown in Table 4 was prepared. For the admixture, "SP" was added by weight 0.8% by weight to the weight of cement and "AD2" was added by weight 0.6% by weight to weight of cement. For kneading, the ingredients were added, kneaded for 30 seconds, then scraped off, kneaded for another 90 seconds, allowed to stand for 5 minutes, then kneaded for 30 seconds, and then discharged. The kneading amount was 80 L.
Figure 0007097015000003
Figure 0007097015000004

（締固め）
図１として説明した型枠内に上記モルタル又はコンクリートを流し込んだ。モルタルについては、締固めを実施することなく密実に充填した。各コンクリートについては、目視で粗な部分が観察される程度に未充填部分が存在した。 (Compacting)
The mortar or concrete was poured into the formwork described as FIG. The mortar was packed tightly without compaction. For each concrete, there were unfilled parts to the extent that rough parts were visually observed.

型枠の外側において散乱型のＲＩ計測器をあてがい、コンクリートに棒状バイブレータを刺して振動させた。振動は３０秒間にわたって行い、その間、放射線をカウントした。いずれも振動させている最中にカウント値が図２に示されたような変化を辿りながら、一定の値幅内に入る程度に安定した。 A scattering type RI measuring instrument was applied to the outside of the formwork, and a rod-shaped vibrator was pierced into the concrete to vibrate. The vibration was performed for 30 seconds, during which the radiation was counted. In each case, the count value was stable to the extent that it was within a certain price range while following the change as shown in FIG. 2 while vibrating.

モルタル及び各コンクリートの締固め前後（ただしモルタルは締固めを行っていない）のカウント数を図３のグラフに示した。図３のグラフにおいて、横軸は密度の高低を示しており、左側から右側へ向けて、密度の低いものから高いものを並べている。凡例のうち％表示をしているものは、表２に示したものに対応しており、「（後）」の文字を付したものはそれぞれの締固め後を意味している。ここで、「１００％」及び「１５０％」のものが締固め前のカウント数が高くなっているのは、粗骨材の量が相対的に多く、未充填箇所が多かったことが原因と考えられる。 The counts before and after compaction of the mortar and each concrete (however, the mortar is not compacted) are shown in the graph of FIG. In the graph of FIG. 3, the horizontal axis shows the high and low densities, and the ones with low density to the high density are arranged from the left side to the right side. Of the legends, those with% indication correspond to those shown in Table 2, and those with the letters "(after)" mean after each compaction. Here, the reason why the counts of "100%" and "150%" before compaction are high is that the amount of coarse aggregate is relatively large and there are many unfilled parts. Conceivable.

各コンクリートはいずれも、締固めによってカウント数が低下していることが分かる（グラフ中の下向き矢印）。すなわち、締固めによって密度が高くなっていることがわかる。従って、締固めの程度を放射線のカウント数の変化によって判定することができることが分かる。また、密度の高まりの程度は、粗骨材の配合割合が高いコンクリートほど大きくなっている。 It can be seen that the count number of each concrete is reduced by compaction (down arrow in the graph). That is, it can be seen that the density is increased by compaction. Therefore, it can be seen that the degree of compaction can be determined by the change in the number of radiation counts. In addition, the degree of increase in density is greater for concrete with a higher proportion of coarse aggregate.

本発明は、コンクリート構造物の施工において利用することができる。 The present invention can be used in the construction of concrete structures.

１…型枠、３…コンクリート、５…ＲＩ計測器（コンクリートの締固め度判定装置）、５ａ…線源部、５ｂ…受信部、７…棒状バイブレータ。 1 ... Formwork, 3 ... Concrete, 5 ... RI measuring instrument (concrete compaction degree determination device), 5a ... Source unit, 5b ... Receiver unit, 7 ... Rod-shaped vibrator.

Claims (4)

型枠の中に充填されたコンクリートに前記型枠外から放射線を照射し、前記コンクリートを散乱し通過した前記放射線を前記型枠の外に設置した散乱型のＲＩ計測器により計測する計測工程を有し、
前記計測工程では、前記コンクリートを締め固めながら及び締め固めた後に、前記放射線の計測を連続的又は離散的に行い、
前記ＲＩ計測器が示す計測値が所定の値領域に収束した時点、又は、前記ＲＩ計測器が示す計測値が所定の値領域内に達した時点を締固め完了と判断する、コンクリートの締固め度判定方法。 There is a measurement process in which the concrete filled in the formwork is irradiated with radiation from outside the formwork, and the radiation that has scattered and passed through the concrete is measured by a scattering type RI measuring instrument installed outside the formwork. death,
In the measurement step, the radiation is continuously or discretely measured while compacting and after compacting the concrete.
Concrete compaction is determined to be complete when the measured value indicated by the RI measuring instrument converges to a predetermined value region or when the measured value indicated by the RI measuring instrument reaches a predetermined value region. Degree judgment method. 前記所定の値領域は、前記コンクリートの配合から推定される締固め後の密度に基づく理論値領域である、請求項１記載のコンクリートの締固め度判定方法。 The method for determining the degree of compaction of concrete according to claim 1, wherein the predetermined value region is a theoretical value region based on the density after compaction estimated from the compounding of the concrete. 前記ＲＩ計測器による計測を前記型枠の外における複数の箇所で行う、請求項１又は２記載のコンクリートの締固め度判定方法。 The method for determining the degree of compaction of concrete according to claim 1 or 2, wherein the measurement by the RI measuring instrument is performed at a plurality of places outside the formwork. 前記コンクリートは、鉄筋の周囲に充填されたものであり、
前記計測工程では、前記コンクリートのうち前記型枠と前記鉄筋との間の領域に存在するコンクリートを対象とする、請求項１～３のいずれか一項記載のコンクリートの締固め度判定方法。 The concrete is filled around the reinforcing bar and
The method for determining the degree of compaction of concrete according to any one of claims 1 to 3 , wherein in the measurement step, the concrete existing in the region between the formwork and the reinforcing bar among the concrete is targeted.
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