JP2008290902A - Method for determining blending ratio of expansive admixture for concrete - Google Patents

Method for determining blending ratio of expansive admixture for concrete Download PDF

Info

Publication number
JP2008290902A
JP2008290902A JP2007137149A JP2007137149A JP2008290902A JP 2008290902 A JP2008290902 A JP 2008290902A JP 2007137149 A JP2007137149 A JP 2007137149A JP 2007137149 A JP2007137149 A JP 2007137149A JP 2008290902 A JP2008290902 A JP 2008290902A
Authority
JP
Japan
Prior art keywords
concrete
strain
blending ratio
evaluation
construction site
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
JP2007137149A
Other languages
Japanese (ja)
Other versions
JP5046278B2 (en
Inventor
Takashi Hanebuchi
貴士 羽渕
Takahiko Amino
貴彦 網野
Ryoichi Tanaka
亮一 田中
Kentaro Suhara
健太郎 栖原
Teruhiro Hori
彰宏 保利
Kiminobu Ashida
公伸 芦田
Satoru Teramura
悟 寺村
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Denka Co Ltd
Toa Corp
Original Assignee
Toa Corp
Denki Kagaku Kogyo KK
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Toa Corp, Denki Kagaku Kogyo KK filed Critical Toa Corp
Priority to JP2007137149A priority Critical patent/JP5046278B2/en
Publication of JP2008290902A publication Critical patent/JP2008290902A/en
Application granted granted Critical
Publication of JP5046278B2 publication Critical patent/JP5046278B2/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Landscapes

  • On-Site Construction Work That Accompanies The Preparation And Application Of Concrete (AREA)
  • Sampling And Sample Adjustment (AREA)
  • Preparation Of Clay, And Manufacture Of Mixtures Containing Clay Or Cement (AREA)
  • Curing Cements, Concrete, And Artificial Stone (AREA)

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for determining the blending ratio of an expansive admixture for concrete by which an adequate blending ratio of the expansive admixture corresponding to the conditions or the like required to a concrete structure to be constructed can be obtained and the occurrence of cracks in concrete being placed can be prevented. <P>SOLUTION: A plurality of concrete samples S for estimation, prepared by changing at least blending ratio of an expansive admixture in the blending of concrete used at a construction site are solidified under the same temperature condition as that of the construction site in a state where the deformation in the longitudinal direction of each sample is restricted by a restricting steel pipe 2 of a strain measuring device 1. Then, the strain in the longitudinal direction generated in the restricting steed pipe 2 in the solidification process is measured with a strain indicator 4 as the strain of each concrete sample S. The blending ratio of the expansive admixture is determined based on the generated stress of each concrete sample S, calculated from the measured data with a strain measuring instrument 6. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

本発明は、コンクリート用膨張材の配合割合の決定方法に関し、さらに詳しくは、構築するコンクリート構造物に対する要求条件等に応じた過不足のない適正な膨張材の配合割合を把握して、打設するコンクリートのひび割れを防止できるようにしたコンクリート用膨張材の配合割合の決定方法に関するものである。   The present invention relates to a method for determining the mixing ratio of an expansion material for concrete, and more specifically, grasping the mixing ratio of an appropriate expansion material without excess or deficiency according to the requirements for the concrete structure to be constructed, and placing The present invention relates to a method for determining a mixing ratio of a concrete expansion material that can prevent cracking of concrete.

膨張材を配合することにより、コンクリートのひび割れの発生を抑制する方法が種々提案されている（例えば、特許文献１参照）。従来、コンクリート用膨張材の配合割合は、標準割合が規定されていて、例えば、低添加型膨張材では２０ｋｇ／ｍ３が標準割合となっている。 Various methods for suppressing the occurrence of cracks in concrete by blending an expansion material have been proposed (for example, see Patent Document 1). Conventionally, a standard ratio is specified as a mixing ratio of the expansion material for concrete. For example, 20 kg / m 3 is a standard ratio in a low additive type expansion material.

しかしながら、打設したコンクリートで構築される構造物に対する要求条件や施工条件によっては、膨張材の添加量が標準割合よりも少ない場合であっても十分なひび割れ抑制効果を得られることもある。一方、膨張材の添加量が不足すれば、打設したコンクリートのひび割れの発生を抑制することができない。   However, depending on the requirements and construction conditions for a structure constructed of cast concrete, a sufficient crack suppression effect may be obtained even when the amount of the expanded material added is less than the standard ratio. On the other hand, if the added amount of the expansion material is insufficient, the occurrence of cracks in the placed concrete cannot be suppressed.

そのため、構築するコンクリート構造物に対する要求条件等に応じて、打設したコンクリートのひび割れを防止できる適正な膨張材の配合割合を把握することが必要であった。
特開２００５−３３６０３９号公報 Therefore, it was necessary to grasp the proper proportion of the expansion material that can prevent cracking of the placed concrete according to the requirements for the concrete structure to be constructed.
JP 2005-336039 A

本発明の目的は、構築するコンクリート構造物に対する要求条件等に応じた過不足のない適正な膨張材の配合割合を把握して、打設するコンクリートのひび割れを防止できるようにしたコンクリート用膨張材の配合割合の決定方法を提供することにある。   An object of the present invention is to grasp the mixing ratio of an appropriate expansion material without excess or deficiency according to the requirements for the concrete structure to be constructed, and to prevent cracking of the concrete to be placed. It is in providing the determination method of the mixture ratio of.

上記目的を達成するため、本発明のコンクリート用膨張材の配合割合の決定方法は、施工現場で用いるコンクリートの配合のうち、少なくとも膨張材の配合割合を変えて作製した複数の評価用コンクリートを、長さ方向の変形を拘束した状態で所定の温度条件下で固化させ、その固化過程でそれぞれの評価用コンクリートに生じる長さ方向のひずみを測定し、該測定したひずみから算出したそれぞれの評価用コンクリートに生じる応力に基づいて、その施工現場で用いるコンクリートの膨張材の配合割合を決定するようにしたことを特徴とするものである。   In order to achieve the above object, the method for determining the blending ratio of the concrete expansion material according to the present invention includes a plurality of evaluation concretes prepared by changing at least the blending ratio of the expansion material among the concrete blending used at the construction site. Solidify under specified temperature conditions with restrained deformation in the length direction, measure the strain in the length direction generated in each concrete for evaluation during the solidification process, and calculate for each evaluation calculated from the measured strain Based on the stress generated in the concrete, the mixing ratio of the concrete expansion material used in the construction site is determined.

ここで、前記所定の温度条件を施工現場と同じ温度条件とすることもできる。また、例えば、前記それぞれの評価用コンクリートに生じる応力が一定になった時の応力に基づいて、その施工現場で用いるコンクリートの膨張材の配合割合を決定するようにする。また、本発明において、膨張材の配合割合は、例えば、コンクリート１ｍ３に対して３０Ｋｇ以下の範囲にする。 Here, the predetermined temperature condition may be the same temperature condition as the construction site. Further, for example, based on the stress when the stress generated in each evaluation concrete becomes constant, the blending ratio of the concrete expansion material used at the construction site is determined. Further, in the present invention, the mixing ratio of the expandable material, for example, the following range 30Kg against concrete 1 m 3.

本発明のコンクリート用膨張材の配合割合の決定方法によれば、施工現場で用いるコンクリートの配合のうち、膨張材の配合割合を変えて作製した複数の評価用コンクリートを用いて、長さ方向の変形を拘束した状態で所定の温度条件下で固化させることにより、施工現場に近似した状況を再現することができる。そして、コンクリートの固化過程でそれぞれの評価用コンクリートに生じる長さ方向のひずみを測定し、該測定したひずみから算出したそれぞれの評価用コンクリートに生じる応力に基づいて、その施工現場で用いるコンクリートの膨張材の配合割合を決定することによって、膨張材の配合割合と固化するコンクリートに生じる応力との相関関係を把握することができる。これにより、コンクリート構造物に対する要求条件や施工条件に応じた過不足のない適正な膨張材の配合割合が把握でき、この適正な配合割合で膨張材を配合することにより、打設するコンクリートのひび割れを防止することが可能となる。   According to the method for determining the blending ratio of the expansion material for concrete according to the present invention, among the concrete blending used at the construction site, using a plurality of evaluation concretes prepared by changing the blending ratio of the expanding material, By solidifying under a predetermined temperature condition in a state where deformation is constrained, a situation approximate to the construction site can be reproduced. Then, the strain in the length direction generated in each evaluation concrete during the solidification process of the concrete is measured, and based on the stress generated in each evaluation concrete calculated from the measured strain, the expansion of the concrete used in the construction site By determining the blending ratio of the material, it is possible to grasp the correlation between the blending ratio of the expanding material and the stress generated in the solidified concrete. As a result, it is possible to grasp the proportion of the appropriate expansive material with no excess or deficiency according to the requirements and construction conditions for the concrete structure. By blending the expansive with this proper proportion, the concrete to be placed is cracked. Can be prevented.

以下、本発明のコンクリート用膨張材の配合割合の決定方法を図に示した実施形態に基づいて説明する。   Hereinafter, the method for determining the blending ratio of the concrete expansion material of the present invention will be described based on the embodiments shown in the drawings.

コンクリートのひび割れを防止しようとする場合、一般にセメント、膨張材、細骨材、粗骨材、混和剤、水をそれぞれ所定の配合割合で混練りしたコンクリートを用いるが、本発明では施工現場で用いるコンクリートの配合のうち、主に膨張材の配合割合を変えた複数種類の評価用コンクリートＳを作製し、図１、２に例示するひずみ測定装置１によって、それぞれの評価用コンクリートＳに生じるひずみを測定する。単純に膨張材の配合割合だけを変えた評価用コンクリートＳを作製することもできるが、膨張材の配合割合に連動してセメントの配合割合を必然的に変える必要がある場合は、膨張材およびセメントの配合割合を変えた複数種類の評価用コンクリートＳを作製する。   When trying to prevent cracking of concrete, generally cement, expanded material, fine aggregate, coarse aggregate, admixture, and water, each of which is kneaded at a predetermined blending ratio, are used at the construction site in the present invention. Among the concrete blends, a plurality of types of evaluation concrete S in which the proportion of the expansion material is mainly changed is prepared, and the strain generated in each evaluation concrete S is measured by the strain measuring apparatus 1 illustrated in FIGS. taking measurement. The evaluation concrete S can be produced by simply changing the blending ratio of the expanding material. However, if the blending ratio of the cement is necessarily changed in conjunction with the blending ratio of the expanding material, the expanding material and A plurality of types of evaluation concrete S with different cement proportions are prepared.

ひずみ測定装置１は、４本の拘束鋼管２の長さ方向両端部に反力鋼板５を固設して、４本の拘束鋼管２の内側に評価用コンクリートＳを設置する構造になっている。ダンベル状の評価用コンクリートＳは、外周に拘束治具３が取付けられ、拘束治具３が反力鋼板５に固定されている。それぞれの拘束鋼管２は、ひずみゲージ４が取付けられた状態で断熱材７が被覆され、ひずみゲージ４はひずみ計測器６に接続されている。   The strain measuring apparatus 1 has a structure in which reaction force steel plates 5 are fixed to both ends in the length direction of the four constraining steel pipes 2 and the evaluation concrete S is installed inside the four constraining steel pipes 2. . In the dumbbell-shaped evaluation concrete S, the restraining jig 3 is attached to the outer periphery, and the restraining jig 3 is fixed to the reaction steel plate 5. Each restraint steel pipe 2 is covered with a heat insulating material 7 in a state where the strain gauge 4 is attached, and the strain gauge 4 is connected to a strain measuring instrument 6.

これら拘束鋼管２には流体循環路９が接続され、流体循環路９を介して内部が連通している。流体循環路９にはヒーター１０、電動ポンプ１２、温度制御装置１１が備わっている。４本の拘束鋼管２および流体循環路９には、ヒーター１０で温度調節された水等の温調流体が電動ポンプ１２によって循環する。この温調流体の温度は、温度センサ７による検知温度が温度制御装置１１に入力され、この検知温度に基づいてヒーター１０の加温温度が制御されるようになっている。   A fluid circulation path 9 is connected to these constraining steel pipes 2, and the inside communicates via the fluid circulation path 9. The fluid circulation path 9 includes a heater 10, an electric pump 12, and a temperature control device 11. A temperature control fluid such as water whose temperature is adjusted by the heater 10 circulates in the four restraining steel pipes 2 and the fluid circulation path 9 by the electric pump 12. As the temperature of the temperature adjusting fluid, the temperature detected by the temperature sensor 7 is input to the temperature control device 11, and the heating temperature of the heater 10 is controlled based on the detected temperature.

このひずみ測定装置１では、拘束鋼管２による拘束力が、反力鋼板５および拘束治具３を介して評価用コンクリートＳに伝達されて、評価用コンクリートＳの長さ方向の変形が拘束される。そして、評価用コンクリートＳの長さ方向のひずみと同じひずみ量となる拘束鋼管２の長さ方向のひずみが、ひずみゲージ４により測定される。この測定されたひずみデータが、ひずみ測定計測器６に入力され、測定ひずみに基づいて評価用コンクリートＳに生じる長さ方向の応力が算出される。   In this strain measuring apparatus 1, the restraining force by the restraining steel pipe 2 is transmitted to the evaluation concrete S via the reaction force steel plate 5 and the restraining jig 3, and the deformation in the length direction of the evaluation concrete S is restrained. . Then, the strain in the length direction of the constrained steel pipe 2 having the same strain amount as the strain in the length direction of the evaluation concrete S is measured by the strain gauge 4. The measured strain data is input to the strain measuring instrument 6, and the stress in the length direction generated in the evaluation concrete S is calculated based on the measured strain.

次いで、このひずみ測定装置１によって、評価用コンクリートＳが固化する過程で評価用コンクリートＳに生じる応力を算出する手順を説明する。   Next, a procedure for calculating the stress generated in the evaluation concrete S in the process of solidifying the evaluation concrete S by the strain measuring device 1 will be described.

図１に例示するように、それぞれの評価用コンクリートＳをひずみ測定装置１にセットして、ひずみ測定装置１を設置した実験室（温度可変室）の温度を、施工現場と同じ温度条件に設定する。施工現場と同じ温度条件は、例えば、施工現場におけるコンクリートの打設温度、外気温等を入力して、図３に例示するような、打設したコンクリートの内部の温度履歴を、予めＦＥＭ解析等により求めておく。拘束鋼管２には、ひずみ測定中に評価用コンクリートＳに付与した温度条件の影響が及ばないように、一定温度（例えば２０℃）の温調流体を循環させる。   As illustrated in FIG. 1, each evaluation concrete S is set in the strain measuring device 1, and the temperature of the laboratory (temperature variable chamber) in which the strain measuring device 1 is installed is set to the same temperature condition as the construction site. To do. As for the same temperature conditions as the construction site, for example, the concrete placement temperature and the outside air temperature at the construction site are input, and the temperature history inside the placed concrete as illustrated in FIG. It asks by. A temperature-controlled fluid having a constant temperature (for example, 20 ° C.) is circulated in the constraining steel pipe 2 so as not to be affected by the temperature condition applied to the evaluation concrete S during strain measurement.

これにより、施工現場と同様の温度条件を再現することができ、より施工現場に近い精度のよいひずみデータを取得することができる。   Thereby, the temperature conditions similar to the construction site can be reproduced, and accurate strain data closer to the construction site can be obtained.

次いで、評価用コンクリートＳの打設してから固化するまでの固化過程における拘束鋼管２の長さ方向のひずみをひずみケージ４により検知し、この検知データをひずみ計測器６に入力する。ひずみ計測器６では、ひずみケージ４の検知データに基づいて評価用コンクリートＳに生じている応力が算出される。   Next, the strain in the length direction of the constrained steel pipe 2 in the solidification process from the placement of the evaluation concrete S to the solidification is detected by the strain cage 4, and this detection data is input to the strain measuring device 6. In the strain measuring instrument 6, the stress generated in the evaluation concrete S is calculated based on the detection data of the strain cage 4.

このようにして、施工現場と同じ温度条件下において、長さ方向を拘束された状態のそれぞれの評価用コンクリートＳに生じる応力を算出して、膨張材の配合割合と評価用コンクリートＳの発生応力との相関関係を把握する。この相関関係を用いて、例えば、それぞれの評価用コンクリートＳに生じる応力が経時的に一定になった時の応力に基づいて、構築しようとするコンクリート構造物に対する要求条件を満足する膨張材の配合割合を決定する。即ち、コンクリート構造物に対して設定された許容応力を超えない発生応力となる評価用コンクリートＳを選択し、その選択した評価用コンクリートＳの膨張材の配合割合を、その施工現場で用いるコンクリートに適用する。   In this way, the stress generated in each evaluation concrete S in a state in which the length direction is constrained under the same temperature conditions as the construction site is calculated, and the mixing ratio of the expansion material and the generated stress of the evaluation concrete S are calculated. To understand the correlation with. Using this correlation, for example, based on the stress when the stress generated in each evaluation concrete S becomes constant over time, the composition of the expansion material satisfying the requirements for the concrete structure to be constructed Determine the percentage. That is, the evaluation concrete S that has a generated stress that does not exceed the allowable stress set for the concrete structure is selected, and the proportion of the expanded material in the selected evaluation concrete S is set to the concrete used at the construction site. Apply.

上記のような評価用コンクリートＳのひずみ測定を行なうことにより、コンクリート構造物ごとに異なる要求条件や施工条件に応じた過不足のない適正な膨張材の配合割合が把握できるようになる。したがって、このように決定した配合割合の膨張材を含有したコンクリートを用いることにより、構築したコンクリート構造物のコンクリートのひび割れを防止することが可能になる。   By performing the strain measurement of the evaluation concrete S as described above, it is possible to grasp an appropriate blending ratio of the expansion material without excess or deficiency according to different requirements and construction conditions for each concrete structure. Therefore, it is possible to prevent cracking of the concrete of the constructed concrete structure by using the concrete containing the expansion material having the blending ratio determined as described above.

ところで、コンクリートの拘束条件（全体の断面積に対する鉄筋の断面積の割合）やコンクリートを固化させる際の温度条件、セメントの種類、配合量等が、ある範囲内であれば、これらの条件の違いによってコンクリートの膨張量（発生応力）は、大きく影響を受けることがない。そのため、評価用コンクリートＳを固化させる際の温度条件を、施工現場とは異なる温度条件にした場合であっても、施工現場と同じ条件下の場合に比して精度は低下するものの、許容できる精度を有する膨張材の配合割合と評価用コンクリートＳとの相関関係を把握することができる。そこで、所定の温度条件下（例えば、２０℃一定、施工現場におけるコンクリートの打設温度または施工現場における外気温など）において評価用コンクリートＳのひずみ測定を行なうようにしてもよい。   By the way, if the concrete restraint condition (ratio of the cross-sectional area of the reinforcing bar to the total cross-sectional area), the temperature condition when solidifying the concrete, the type of cement, and the blending amount are within a certain range, the difference between these conditions Therefore, the expansion amount (generated stress) of the concrete is not greatly affected. Therefore, even if the temperature condition when solidifying the concrete S for evaluation is set to a temperature condition different from that at the construction site, the accuracy is lower than that under the same conditions as at the construction site, but it is acceptable. It is possible to grasp the correlation between the mixing ratio of the expanding material having accuracy and the evaluation concrete S. Therefore, the strain measurement of the evaluation concrete S may be performed under a predetermined temperature condition (for example, constant 20 ° C., concrete placement temperature at the construction site or outside air temperature at the construction site).

また、評価用コンクリートＳのひずみ測定は、上記に例示したひずみ測定装置１を用いた測定に限らず、評価用コンクリートＳの長さ方向の変形を拘束した状態で所定の温度条件下で、評価用コンクリートＳの長さ方向のひずみを測定できるものであればよい。
例えば、その他にＪＩＳ Ａ ６２０２で規定されているＡ法やＢ法に基づいて行なうことができる。評価用コンクリートＳの長さ方向のひずみは、評価用コンクリートＳの長さ方向に鉄筋を埋設し、この鉄筋の長さ方向のひずみを測定することにより取得するようにすることもできる。 In addition, the strain measurement of the evaluation concrete S is not limited to the measurement using the strain measuring apparatus 1 exemplified above, and is evaluated under a predetermined temperature condition in a state where the deformation in the length direction of the evaluation concrete S is constrained. What is necessary is just to be able to measure the strain in the length direction of the concrete S for construction.
For example, it can be performed based on the A method and the B method prescribed in JIS A 6202. The strain in the length direction of the evaluation concrete S can be obtained by embedding a reinforcing bar in the length direction of the evaluation concrete S and measuring the strain in the length direction of the reinforcing bar.

本発明によって決定される膨張材の配合割合は、例えば、一般に標準として規定されているコンクリート１ｍ３に対して２０ｋｇ以下或いは３０ｋｇ以下の範囲であるが、この配合割合以上の範囲について適用することも可能である。 The proportion of the expansion material determined according to the present invention is, for example, a range of 20 kg or less or 30 kg or less with respect to 1 m 3 of concrete generally defined as a standard. Is possible.

ある施工現場を想定し、セメント（高炉セメントＢ種（比重３．０５））、膨張材（エトリンガイト石灰複合系（比重２．８６））、細骨材(川砂（比重２．６２）)、粗骨材(川砂利（比重２．６５）)、混和剤(高性能ＡＥ減水剤)、水（上水道水）をそれぞれ同一種類として配合したことを共通条件として、表１に示すように主に膨張材の添加量（配合割合）を変化させて評価用コンクリート（サンプル１〜３）を作製した。この膨張材の標準添加量は、コンクリート１ｍ３に対して２０ｋｇである。セメントの添加量は、膨張材の添加量の変化に連動して、セメントと膨張材の合計量がそれぞれのサンプルで同一になるようにした。これらサンプル１〜３が固化する際に生じる長さ方向のひずみを、図１、２に例示したひずみ測定装置を用いて、（財）建材試験センター（ＪＳＴＭ）に規定されているＪＳＴＭ Ｃ ８２０４：１９９９「コンクリートの水和熱による温度ひび割れ試験方法」に準拠して測定した。温度条件は、想定した施工現場と同じになるように設定した図３に示す温度データを用いるとともに、温調流体を一定温度（２０℃）に設定した。 Assuming a certain construction site, cement (blast furnace cement type B (specific gravity 3.05)), expansion material (etringite lime composite system (specific gravity 2.86)), fine aggregate (river sand (specific gravity 2.62)), coarse Mainly expanded as shown in Table 1 under the common condition that aggregates (river gravel (specific gravity 2.65)), admixture (high performance AE water reducing agent), and water (tap water) are blended as the same type. Evaluation concrete (samples 1 to 3) was produced by changing the amount of the material added (mixing ratio). The standard addition amount of this expansion material is 20 kg with respect to 1 m 3 of concrete. The amount of cement added was adjusted so that the total amount of cement and intumescent material was the same for each sample in conjunction with the change in the amount of intumescent material added. The strain in the length direction generated when these samples 1 to 3 are solidified using the strain measuring apparatus illustrated in FIGS. 1 and 2, JSTM C 8204 specified by the Building Materials Testing Center (JSTM): It was measured according to 1999 “Testing method for temperature cracking of concrete due to heat of hydration”. As the temperature condition, the temperature data shown in FIG. 3 set to be the same as the assumed construction site was used, and the temperature control fluid was set to a constant temperature (20 ° C.).

尚、いずれのサンプルにおいても材齢７日以降から引張応力が一定となり、ひび割れが確認されなかったため、材齢１２日目以降、温調流体の温度を上昇（３℃／日）させて強制的に引張応力を与えて、各サンプルにひび割れが生じるまで測定を行なった。このひずみ測定に基づいて算出した各サンプルでの発生応力を図４、５に示す。   In any sample, since the tensile stress became constant after 7 days of age and no cracks were observed, the temperature of the temperature control fluid was increased (3 ° C./day) from the 12th day of age. Tensile stress was applied to each sample, and measurement was performed until cracks occurred in each sample. FIGS. 4 and 5 show the generated stress in each sample calculated based on this strain measurement.

Figure 2008290902
Figure 2008290902

図４のグラフの縦軸は、各サンプルに生じた長さ方向の応力を示し、マイナスの値は圧縮応力、プラス値は引張応力を示す。図４の結果から、初期の最大圧縮応力は、サンプル３が最も大きかったが、サンプル１と２とはほぼ同じであった。一方、材齢１２日後における引張応力で比較すると、サンプル１では１．２６Ｎ／ｍｍ２、サンプル２では１．０６Ｎ／ｍｍ２、サンプル３では０．７５Ｎ／ｍｍ２となり、膨張材の添加量を増加させることにより、拘束されて固化するコンクリートに発生する引張応力が低減することが確認できた。 The vertical axis of the graph in FIG. 4 indicates the stress in the length direction generated in each sample, a negative value indicates a compressive stress, and a positive value indicates a tensile stress. From the results shown in FIG. 4, the initial maximum compressive stress was the largest in sample 3, but was almost the same in samples 1 and 2. On the other hand, when compared with the tensile stress after 12 days of material age, Sample 1 has 1.26 N / mm 2 , Sample 2 has 1.06 N / mm 2 , and Sample 3 has 0.75 N / mm 2 . By increasing it, it was confirmed that the tensile stress generated in the concrete that is constrained and solidified is reduced.

図５は、図４のデータに基づいて、サンプルに生じる引張応力が安定した材齢１２日目におけるサンプル２、３での発生応力を、サンプル１での発生応力に対する比として整理したものである。図５の結果から、サンプル２では約０．８４、サンプル３では約０．６０であり、標準添加量であるサンプル３よりも添加量が小さいサンプル２であっても温度応力の低減を図れることが確認できた。また、サンプル２の発生応力の低減量は、サンプル３に対して４０％程度であり、発生応力の低減量と膨張材の添加量とは、単純な比例関係ではないことが確認でき、本発明を適用することでコンクリート構造物に対する要求条件等に適合した最適な膨張材の添加量が把握できることが判る。   FIG. 5 is an arrangement of the stresses generated in samples 2 and 3 on the 12th day of age when the tensile stress generated in the sample is stable based on the data in FIG. 4 as a ratio to the generated stress in sample 1. . From the result of FIG. 5, it is about 0.84 for sample 2 and about 0.60 for sample 3, and it is possible to reduce the temperature stress even with sample 2 having a smaller addition amount than sample 3 which is the standard addition amount. Was confirmed. In addition, the reduction amount of the generated stress of the sample 2 is about 40% with respect to the sample 3, and it can be confirmed that the reduction amount of the generated stress and the addition amount of the expansion material are not a simple proportional relationship. It can be seen that the optimal amount of expansion material added to meet the requirements for concrete structures can be grasped by applying.

また、サンプル１〜３の線膨張係数を把握するために、それぞれのサンプルと同じ配合で、ひずみ計および熱電対を埋設した縦１０ｃｍ×横１０ｃｍ×長さ４０ｃｍの無拘束サンプルを作製し、自由膨張ひずみ（μ）の測定を行なった。その結果を図６に示す。   In addition, in order to grasp the linear expansion coefficients of Samples 1 to 3, unconstrained samples of 10cm in length, 10cm in width, and 40cm in length with a strain meter and thermocouple embedded in the same composition as each sample were freely created. The expansion strain (μ) was measured. The result is shown in FIG.

図６の結果から、温度上昇時の線膨張係数（α１）は、膨張材の添加量の増加に伴い大きくなる傾向がみられた。一方、温度下降時（α２）については、サンプル１とサンプル２とはほとんど違いが見られなかったのに対し、サンプル３はサンプル１に対して約０．８７倍となり、やや小さい値であった。これにより、膨張材の添加量が２０ｋｇ／ｍ３よりも少ない場合、線膨張係数を変えた温度応力解析手法では、膨張材の添加量の違いによるひび割れ抑制効果を評価することが難しいことが判る。 From the result of FIG. 6, the linear expansion coefficient (α1) at the time of temperature rise tended to increase with the increase in the amount of expansion material added. On the other hand, when the temperature dropped (α2), sample 1 and sample 2 showed almost no difference, while sample 3 was about 0.87 times that of sample 1 and was slightly smaller. . As a result, it can be seen that when the amount of the expanded material added is less than 20 kg / m 3, it is difficult to evaluate the effect of suppressing cracking due to the difference in the added amount of the expanded material by the temperature stress analysis method with the changed linear expansion coefficient. .

本発明に用いるひずみ測定装置を正面方向で例示する説明図である。It is explanatory drawing which illustrates the distortion | strain measuring apparatus used for this invention in a front direction. 図１のひずみ測定装置を側面方向で例示する説明図である。It is explanatory drawing which illustrates the distortion | strain measuring apparatus of FIG. 1 in a side surface direction. ひずみ測定を行なう際に、評価用コンクリートに付与する温度条件を例示するグラフ図である。It is a graph which illustrates the temperature conditions provided to the concrete for evaluation, when performing a strain measurement. 評価用コンクリートの固化過程においてに発生する応力を例示するグラフ図である。It is a graph which illustrates the stress which generate | occur | produces in the solidification process of the concrete for evaluation. 膨張材の添加量と、評価用コンクリートに生じる応力との関係を例示するグラフ図である。It is a graph which illustrates the relationship between the addition amount of an expandable material, and the stress which arises in the concrete for evaluation. 無拘束の評価用コンクリートに生じるひずみと温度との関係を例示するグラフ図である。It is a graph which illustrates the relationship between the distortion which arises in the unconstrained evaluation concrete, and temperature.

符号の説明Explanation of symbols

１ ひずみ測定装置
２ 拘束鋼管
３ 拘束治具
４ ひずみゲージ
５ 反力鋼板
６ ひずみ計測器
７ 温度センサ
８ 断熱材
９ 流体循環路
１０ ヒーター
１１ 温度制御装置
１２ 電動ポンプ
Ｓ 評価用コンクリート DESCRIPTION OF SYMBOLS 1 Strain measuring device 2 Restraint steel pipe 3 Restraint jig 4 Strain gauge 5 Reaction force steel plate 6 Strain measuring instrument 7 Temperature sensor 8 Heat insulating material 9 Fluid circulation path 10 Heater 11 Temperature control device 12 Electric pump S Concrete for evaluation

Claims (4)

施工現場で用いるコンクリートの配合のうち、少なくとも膨張材の配合割合を変えて作製した複数の評価用コンクリートを、長さ方向の変形を拘束した状態で所定の温度条件下で固化させ、その固化過程でそれぞれの評価用コンクリートに生じる長さ方向のひずみを測定し、該測定したひずみから算出したそれぞれの評価用コンクリートに生じる応力に基づいて、その施工現場で用いるコンクリートの膨張材の配合割合を決定するようにしたコンクリート用膨張材の配合割合の決定方法。   Of the concrete mix used at the construction site, at least a plurality of evaluation concrete prepared by changing the blending ratio of the expansion material is solidified under a predetermined temperature condition with the deformation in the length direction restricted, and the solidification process Measure the strain in the length direction that occurs in each evaluation concrete with, and based on the stress that occurs in each evaluation concrete calculated from the measured strain, determine the proportion of the concrete expansion material used at the construction site A method of determining the blending ratio of the concrete expansion material. 前記所定の温度条件を施工現場と同じ温度条件とする請求項１に記載のコンクリート用膨張材の配合割合の決定方法。   The method for determining the blending ratio of the concrete expansion material according to claim 1, wherein the predetermined temperature condition is the same as the construction site. 前記それぞれの評価用コンクリートに生じる応力が一定になった時の応力に基づいて、その施工現場で用いるコンクリートの膨張材の配合割合を決定するようにした請求項１または２に記載のコンクリート用膨張材の配合割合の決定方法。   The concrete expansion according to claim 1 or 2, wherein the proportion of the expansion material of the concrete used at the construction site is determined based on the stress when the stress generated in each evaluation concrete becomes constant. A method for determining the mixing ratio of materials. 前記膨張材の配合割合が、コンクリート１ｍ３に対して３０Ｋｇ以下である請求項１〜３のいずれかに記載のコンクリート用膨張材の配合割合の決定方法。 The method for determining the blending ratio of an expanding material for concrete according to any one of claims 1 to 3 , wherein the blending ratio of the expanding material is 30 kg or less with respect to 1 m3 of concrete.
JP2007137149A 2007-05-23 2007-05-23 Method for determining the proportion of expansion material for concrete Active JP5046278B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2007137149A JP5046278B2 (en) 2007-05-23 2007-05-23 Method for determining the proportion of expansion material for concrete

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2007137149A JP5046278B2 (en) 2007-05-23 2007-05-23 Method for determining the proportion of expansion material for concrete

Publications (2)

Publication Number Publication Date
JP2008290902A true JP2008290902A (en) 2008-12-04
JP5046278B2 JP5046278B2 (en) 2012-10-10

Family

ID=40166028

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2007137149A Active JP5046278B2 (en) 2007-05-23 2007-05-23 Method for determining the proportion of expansion material for concrete

Country Status (1)

Country Link
JP (1) JP5046278B2 (en)

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2011169894A (en) * 2010-01-25 2011-09-01 Shimizu Corp Quality control testing method for crack-resistant concrete
JP2012107941A (en) * 2010-11-16 2012-06-07 Taiheiyo Cement Corp Method for determining compounding amount of shrinkage reducing agent
JP2013015382A (en) * 2011-07-02 2013-01-24 Shimizu Corp Method for testing quality management of crack suppression control
JP2013160547A (en) * 2012-02-02 2013-08-19 Shimizu Corp Method for testing concrete quality management
JP2013231598A (en) * 2012-04-27 2013-11-14 Taiheiyo Cement Corp Quantitative evaluation method of crack reduction effect by shrinkage-reducing material, and selection method of shrinkage-reducing material
JP2016130446A (en) * 2015-01-09 2016-07-21 日本車輌製造株式会社 Manufacturing method of composite floor slab, management method of composite floor slab, manufacturing method of concrete structure and management method of concrete structure
CN108106895A (en) * 2017-12-20 2018-06-01 西安科技大学 For the non-linear crack processing unit (plant) and its processing method of fluid permeability experiment

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2004217514A (en) * 2002-12-26 2004-08-05 Sumitomo Osaka Cement Co Ltd Concrete material, concrete structure, and its manufacturing method
JP2006232625A (en) * 2005-02-25 2006-09-07 Sumitomo Osaka Cement Co Ltd Concrete base material for placing at cold time, concrete structure using the base material and method of manufacturing the same

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2004217514A (en) * 2002-12-26 2004-08-05 Sumitomo Osaka Cement Co Ltd Concrete material, concrete structure, and its manufacturing method
JP2006232625A (en) * 2005-02-25 2006-09-07 Sumitomo Osaka Cement Co Ltd Concrete base material for placing at cold time, concrete structure using the base material and method of manufacturing the same

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2011169894A (en) * 2010-01-25 2011-09-01 Shimizu Corp Quality control testing method for crack-resistant concrete
JP2012107941A (en) * 2010-11-16 2012-06-07 Taiheiyo Cement Corp Method for determining compounding amount of shrinkage reducing agent
JP2013015382A (en) * 2011-07-02 2013-01-24 Shimizu Corp Method for testing quality management of crack suppression control
JP2013160547A (en) * 2012-02-02 2013-08-19 Shimizu Corp Method for testing concrete quality management
JP2013231598A (en) * 2012-04-27 2013-11-14 Taiheiyo Cement Corp Quantitative evaluation method of crack reduction effect by shrinkage-reducing material, and selection method of shrinkage-reducing material
JP2016130446A (en) * 2015-01-09 2016-07-21 日本車輌製造株式会社 Manufacturing method of composite floor slab, management method of composite floor slab, manufacturing method of concrete structure and management method of concrete structure
CN108106895A (en) * 2017-12-20 2018-06-01 西安科技大学 For the non-linear crack processing unit (plant) and its processing method of fluid permeability experiment

Also Published As

Publication number Publication date
JP5046278B2 (en) 2012-10-10

Similar Documents

Publication Publication Date Title
JP5046278B2 (en) Method for determining the proportion of expansion material for concrete
Cortas et al. Effect of the water saturation of aggregates on the shrinkage induced cracking risk of concrete at early age
Beushausen et al. The influence of curing on restrained shrinkage cracking of bonded concrete overlays
Maruyama et al. Impact of time-dependant thermal expansion coefficient on the early-age volume changes in cement pastes
Beygi et al. The effect of aging on the fracture characteristics and ductility of self-compacting concrete
Banthia et al. Plastic shrinkage cracking in cementitious repairs and overlays
Klausen et al. The effect of shrinkage reducing admixtures on drying shrinkage, autogenous deformation, and early age stress development of concrete
Abouhussien et al. Experimental and empirical time to corrosion of reinforced concrete structures under different curing conditions
JP2017193470A (en) Concrete product and manufacturing method of concrete product
JP5713640B2 (en) Method for determining the amount of shrinkage reducing agent
Khalifah et al. Stress generation in mass concrete blocks with fly ash and silica fume-an experimental and numerical study
JP4429821B2 (en) Method for estimating expansion stress of expansive concrete
Keskinateş et al. A comprehensive experimental study on the role of matrix structure on the multiple cracking behavior of PVA-ECC
Faria et al. A structural experimental technique to characterize the viscoelastic behavior of concrete under restrained deformations
JP6508467B2 (en) Prediction method of adiabatic temperature rise of concrete
Morimoto et al. 12 ESTIMATION OF STRESS RELAXATION IN CONCRETE AT EARLY AGES
Kim et al. Effect of aggregate on residual mechanical properties of heated ultra-high-strength concrete
Mann The effects of utilizing silica fume in portland cement pervious concrete
JP2011095115A (en) Method of measuring volume change rate and/or length change rate
Werner et al. The effect of various fire‐exposed surface dimensions on the spalling of concrete specimens
JP5222311B2 (en) Method and apparatus for estimating sulfuric acid concentration
Ong et al. Application of image analysis to monitor very early age shrinkage
JP2005091198A (en) Welding fixture for measuring young&#39;s modulus in expansive concrete, and method for measuring young&#39;s modulus in the expansive concrete using the welding fixture
JP2020116743A (en) Method of determining additive amount of cure enhancing material and method of producing hydraulic cured body
Jaskulski et al. Organic phosphorus compounds as heat release regulators in hardening shielding concrete

Legal Events

Date Code Title Description
A621 Written request for application examination

Free format text: JAPANESE INTERMEDIATE CODE: A621

Effective date: 20100422

A131 Notification of reasons for refusal

Free format text: JAPANESE INTERMEDIATE CODE: A131

Effective date: 20111004

A521 Request for written amendment filed

Free format text: JAPANESE INTERMEDIATE CODE: A523

Effective date: 20111130

TRDD Decision of grant or rejection written
A01 Written decision to grant a patent or to grant a registration (utility model)

Free format text: JAPANESE INTERMEDIATE CODE: A01

Effective date: 20120703

A01 Written decision to grant a patent or to grant a registration (utility model)

Free format text: JAPANESE INTERMEDIATE CODE: A01

A61 First payment of annual fees (during grant procedure)

Free format text: JAPANESE INTERMEDIATE CODE: A61

Effective date: 20120711

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20150727

Year of fee payment: 3

R150 Certificate of patent or registration of utility model

Ref document number: 5046278

Country of ref document: JP

Free format text: JAPANESE INTERMEDIATE CODE: R150

Free format text: JAPANESE INTERMEDIATE CODE: R150

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250