JP4239733B2 - Diagnostic method for concrete - Google Patents

Diagnostic method for concrete Download PDF

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JP4239733B2
JP4239733B2 JP2003271882A JP2003271882A JP4239733B2 JP 4239733 B2 JP4239733 B2 JP 4239733B2 JP 2003271882 A JP2003271882 A JP 2003271882A JP 2003271882 A JP2003271882 A JP 2003271882A JP 4239733 B2 JP4239733 B2 JP 4239733B2
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reinforcing bar
heat receiving
strength
fire
receiving temperature
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重彰 馬場
裕 小林
真太郎 道越
正 平尾
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Taisei Corp
Neturen Co Ltd
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Neturen Co Ltd
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Description

本発明は、鉄筋コンクリート部材（鉄骨鉄筋コンクリート部材を含む。）を構成するコンクリート等が火災後に再使用可能であるか否かを診断する方法に関するものである。 The present invention relates to a method for diagnosing whether or not concrete constituting a reinforced concrete member (including a steel reinforced concrete member) can be reused after a fire.

鉄筋コンクリート構造物が火災を受けた場合、その構造物の火災後の再使用性が問題となる。
従来、鉄筋コンクリートを構成する鉄筋やコンクリートは、フェノールフタレイン（ＦＦ）法による中性化試験を実施してその受熱温度が５００℃以下と推定できれば、強度試験を別途実施しなくとも、再使用が可能とされている（例えば、非特許文献１、２参照）。 When a reinforced concrete structure receives a fire, the reusability of the structure after a fire becomes a problem.
Conventionally, rebars and concrete that make up reinforced concrete can be reused even if a strength test is not carried out separately if a neutralization test by the phenolphthalein (FF) method is performed and the heat receiving temperature is estimated to be 500 ° C or less. (For example, refer nonpatent literatures 1 and 2.).

一方、ＦＦ法から鉄筋の受熱温度が５００℃以上と推定される場合には、熱伝導解析を実施して受熱温度を推定するか若しくは構造部材から供試体を採取して引張試験を実施し、その強度を確認して再使用性を検討している。
日本火災学会編、「火災便覧」、第３版、共立出版株式会社、１９９ ７年５月、ｐ．９４５−９５５ 鹿島建設技術研究所、「既存建物の耐力診断と対策」、鹿島出版会、 １９７８年６月、ｐ．８１−１０７ On the other hand, when the heat receiving temperature of the reinforcing bar is estimated to be 500 ° C. or higher from the FF method, the heat receiving temperature is estimated by conducting a heat conduction analysis, or the specimen is taken from the structural member and the tensile test is performed, The reusability is examined by checking its strength.
Japanese Fire Society, “Fire Handbook”, 3rd edition, Kyoritsu Publishing Co., Ltd., May 1999, p. 945-955 Kashima Construction Technology Laboratory, “Diagnosis and Countermeasures for Existing Buildings”, Kashima Press, June 1978, p. 81-107

しかしながら、上記従来の方法のように、鉄筋コンクリートの構造部材（鉄筋コンクリート部材）から供試体を採取する場合には、その後の補修方法に問題が残り、さらにコストアップにもつながる。
また、熱処理を施して強度を高めている鉄筋（５００℃以下で熱処理している場合）については、ＦＦ法で受熱温度が５００℃以下と判断できても、その強度が低下している可能性がある。このような場合、現状では、供試体を採取して引張試験を実施してその強度を確認せざるを得ない。
また、上記鉄筋コンクリート部材に、高強度コンクリートを使用した場合には、受熱温度が３００℃程度でも強度回復が遅々として進まない例も報告されていることから、ＦＦ法ではコンクリートの再使用性を判断することができない。 However, when a specimen is collected from a reinforced concrete structural member (reinforced concrete member) as in the conventional method described above, problems remain in the subsequent repair method, which further increases costs.
In addition, for reinforcing bars that have been heat-treated to increase their strength (when heat-treated at 500 ° C or lower), the strength may be reduced even if the heat receiving temperature can be determined to be 500 ° C or lower by the FF method. There is. In such a case, at present, it is necessary to collect the specimen and perform a tensile test to confirm its strength.
In addition, when high-strength concrete is used for the reinforced concrete member, there are reports of cases where strength recovery does not progress slowly even at a heat receiving temperature of about 300 ° C. I can't judge.

本発明は、かかる事情に鑑みてなされたもので、鉄筋コンクリート部材が火災を受けた際に、当該鉄筋コンクリート部材を構成するコンクリート等が火災後に再使用可能であるか否かを容易かつ速やかに判定することができる診断方法を提供することを目的とする。 The present invention has been made in view of such circumstances, and when a reinforced concrete member receives a fire, it is easily and promptly determined whether or not the concrete constituting the reinforced concrete member can be reused after the fire. it is an object of the invention to provide a cross-sectional process diagnosis Ru can.

請求項１に記載の発明は、鉄筋コンクリート部材が火災を受けた際に、当該鉄筋コンクリート部材を構成するコンクリートが火災後に再使用可能であるか否かを診断する方法であって、火災を受けた鉄筋の硬さを測定して、その測定値から当該鉄筋の受熱温度を推定した後、この受熱温度の推定値から当該鉄筋近傍のコンクリートが再使用可能であるか否かを判定することを特徴とするものである。 The invention according to claim 1 is a method for diagnosing whether or not the concrete constituting the reinforced concrete member is reusable after the fire when the reinforced concrete member is subjected to a fire, After measuring the hardness of the steel and estimating the heat receiving temperature of the reinforcing bar from the measured value, it is determined whether or not the concrete near the reinforcing bar is reusable from the estimated value of the heat receiving temperature. To do.

請求項１に記載の発明によれば、火災を受けた鉄筋の硬さを測定して、その測定値から当該鉄筋の受熱温度を推定した後、この受熱温度の推定値から当該鉄筋近傍のコンクリートが再使用可能であるか否かを判定するようにしたので、例えば、ＦＦ法では判定できなかった高強度コンクリートを使用した場合においても、当該高強度コンクリートが火災後に再使用可能であるか否かを容易かつ正確に判定することができる。 According to invention of Claim 1 , after measuring the hardness of the reinforcing bar which received the fire and estimating the heat receiving temperature of the said reinforcing bar from the measured value, the concrete of the vicinity of the said reinforcing bar from this estimated value of this heat receiving temperature For example, when using high-strength concrete that could not be determined by the FF method, whether or not the high-strength concrete can be reused after a fire is determined. Can be easily and accurately determined.

本発明によれば、火災を受けた鉄筋コンクリート構造物において、再使用できるか否か判断がつかない鉄筋やコンクリート或いは鉄骨に対して破壊検査を実施することなく、非破壊検査にて再使用が可能か否かの判断を行うことができる。   According to the present invention, in a reinforced concrete structure subjected to a fire, it can be reused in a nondestructive inspection without performing a destructive inspection on a reinforcing bar, concrete, or steel frame that cannot be determined whether or not it can be reused. It can be determined whether or not.

以下、図面に基づいて、本発明に係る鉄筋の診断方法の一実施形態について説明する。この診断方法は、図１のフローチャートに示すように、火災を受けた鉄筋の硬さを測定する第１ステップと、鉄筋の硬さの測定値から鉄筋の受熱温度（最高履歴温度）を推定する第２ステップと、受熱温度の推定値から鉄筋の残存強度を導き出す第３ステップと、導き出した残存強度に基づいて鉄筋が再使用可能であるか否かを判定する第４ステップとを有する。   Hereinafter, one embodiment of a diagnostic method for reinforcing bars according to the present invention will be described with reference to the drawings. In this diagnosis method, as shown in the flowchart of FIG. 1, the first step of measuring the hardness of a reinforcing bar subjected to a fire, and the heat receiving temperature (maximum history temperature) of the reinforcing bar is estimated from the measured value of the hardness of the reinforcing bar. The second step includes a third step for deriving the remaining strength of the reinforcing bar from the estimated value of the heat receiving temperature, and a fourth step for determining whether or not the reinforcing bar can be reused based on the derived remaining strength.

本実施形態では、上記第１〜第４ステップの実行に先立って、次に示すように、試験片を用いて鉄筋の受熱温度と残存強度との対応関係、鉄筋の受熱温度（若しくは残存強度）とビッカース硬さとの対応関係をそれぞれ求め、それら対応関係に基づいて、実際に火災を受けた鉄筋のビッカース硬さの測定値から当該鉄筋の受熱温度と残存強度をそれぞれ推定するようにしている。   In the present embodiment, prior to the execution of the first to fourth steps, as shown below, using the test piece, the correspondence between the heat receiving temperature of the reinforcing bar and the residual strength, the heat receiving temperature (or residual strength) of the reinforcing bar. And Vickers hardness are obtained, and based on these correspondences, the heat receiving temperature and residual strength of the reinforcing bar are estimated from the measured values of the Vickers hardness of the reinforcing bar actually fired.

すなわち、鉄筋の受熱温度と残存強度との対応関係を求める場合には、先ず、鉄筋コンクリート部材の断面を設定し、その断面内に存在する各鉄筋（主筋、帯筋）の火災時における温度履歴を推定する。具体的には、図２に示すように、断面寸法、主筋および帯筋の配置と種類、主筋比（ｐｇ）、帯筋比（ｐｗ）、かぶりなどを設定した後、予め設定された等価火災時間（例えば、３０分、６０分、９０分、１２０分、１８０分）の各々について、各鉄筋位置の温度履歴を解析する。例えば、等価火災時間を６０分とした場合、図２の各点Ｐ１、Ｐ２、Ｐ３における温度履歴は、例えば、図３に示すように推定される。   That is, when calculating the correspondence between the heat receiving temperature of the reinforcing bars and the residual strength, first, set the cross section of the reinforced concrete member, and calculate the temperature history of each reinforcing bar (main reinforcing bar, strip) in the cross section during a fire. presume. Specifically, as shown in FIG. 2, after setting the cross-sectional dimensions, the arrangement and types of main and straps, the main bar ratio (pg), the band ratio (pw), the cover, etc., a preset equivalent fire is set. The temperature history of each reinforcing bar position is analyzed for each time (for example, 30 minutes, 60 minutes, 90 minutes, 120 minutes, 180 minutes). For example, when the equivalent fire time is 60 minutes, the temperature history at each of the points P1, P2, and P3 in FIG. 2 is estimated as shown in FIG. 3, for example.

次いで、上記主筋および帯筋と同じ種類の試験片を用意して、その試験片の温度が上記温度履歴に沿って推移するように試験片を加熱した後、ＪＩＳ−Ｚ２２４１（金属材料引張試験方法）に従って、試験片に対する引張試験を常温下で実施する。これにより、上記温度履歴を有する鉄筋の降伏強度または耐力、最大強さ、破断伸びなどを求めることができる。したがって、各等価火災時間に対応する温度履歴に沿って試験片をそれぞれ加熱した後、それら試験片の各々について、上記引張試験を実施するようにすれば、例えば、図４および図５に示すように、鉄筋の受熱温度（等価火災時間）と残存強度（降伏強度または耐力、最大強さ、破断伸び）との対応関係を把握することができる。   Next, after preparing a test piece of the same type as that of the main bar and the strap, and heating the test piece so that the temperature of the test piece changes along the temperature history, JIS-Z2241 (Metallic material tensile test method) ) To carry out a tensile test on the test piece at room temperature. Thereby, the yield strength or yield strength, maximum strength, elongation at break, etc. of the reinforcing bar having the temperature history can be obtained. Therefore, if each of the test pieces is heated according to a temperature history corresponding to each equivalent fire time and then the tensile test is performed on each of the test pieces, for example, as shown in FIGS. In addition, it is possible to grasp the correspondence between the heat receiving temperature (equivalent fire time) of the reinforcing bar and the remaining strength (yield strength or proof strength, maximum strength, elongation at break).

一方、鉄筋の受熱温度（若しくは残存強度）とビッカース硬さとの対応関係を求める場合には、上記と同様に、各等価火災時間に対応する温度履歴に沿って試験片をそれぞれ加熱した後、それら試験片の各々について、硬さ試験機を用いてビッカース硬さを測定する。これにより、例えば、図６および図７に示すように、鉄筋の受熱温度（等価火災時間）とビッカース硬さとの対応関係を把握することができる。   On the other hand, when determining the correspondence between the heat reception temperature (or residual strength) of the reinforcing bar and the Vickers hardness, after heating the test pieces according to the temperature history corresponding to each equivalent fire time, respectively, For each test piece, the Vickers hardness is measured using a hardness tester. Thereby, for example, as shown in FIGS. 6 and 7, it is possible to grasp the correspondence between the heat receiving temperature (equivalent fire time) of the reinforcing bar and the Vickers hardness.

次に、上記対応関係を用いた鉄筋の診断方法について詳細に説明する。
先ず、第１ステップ（Ｓ１）では、診断対象となる鉄筋の硬さを測定する。具体的には、火災を受けた建物に対して目視観察を実施することで、調査すべき鉄筋コンクリート部材を特定した後、当該部材において診断対象となる鉄筋（例えば、帯筋）をはつり出し、その露出部分にビッカース硬さ試験機の圧子を押し当てて当該鉄筋の硬さを測定する。この際に、鉄筋の硬さを１箇所あたり複数点（例えば、１０点）測定し、これを平均するようにすれば、１箇所あたり１点の測定しかできないＦＦ法と比較して、鉄筋の受熱温度および残存強度の推定精度を向上させることができる。 Next, a reinforcing bar diagnosis method using the above correspondence will be described in detail.
First, in the first step (S1), the hardness of a reinforcing bar to be diagnosed is measured. Specifically, after identifying the reinforced concrete member to be investigated by conducting visual observations on the building that has been subjected to the fire, the reinforcing bar (for example, a tie-bar) to be diagnosed in the member is pulled out, The indenter of the Vickers hardness tester is pressed against the exposed portion to measure the hardness of the reinforcing bar. At this time, the hardness of the reinforcing bar is measured at a plurality of points (for example, 10 points) per place, and if this is averaged, the reinforcing bar is compared with the FF method that can measure only one point per place. The estimation accuracy of the heat receiving temperature and the residual strength can be improved.

第２ステップ（Ｓ２）では、鉄筋の受熱温度（等価火災時間）とビッカース硬さとの対応関係に基づいて、上記第１ステップで求めた硬さの測定値から鉄筋の受熱温度を推定する。例えば、鉄筋の受熱温度（等価火災時間）とビッカース硬さとの対応関係が図７（図６）のグラフで表される場合において、硬さの測定値が例えば１５０ＨＶであるときには、鉄筋の受熱温度を７４４℃（等価火災時間が１８０分）と推定することができ、例えば、硬さの測定値が２６０ＨＶであるときには、鉄筋の受熱温度を５２７℃（等価火災時間が９０分）と推定することができる。   In the second step (S2), the heat receiving temperature of the reinforcing bar is estimated from the measured value of the hardness obtained in the first step based on the correspondence between the heat receiving temperature (equivalent fire time) of the reinforcing bar and the Vickers hardness. For example, when the correspondence between the heat reception temperature (equivalent fire time) of the reinforcing bar and the Vickers hardness is represented by the graph of FIG. 7 (FIG. 6), when the measured value of the hardness is, for example, 150 HV, the heat reception temperature of the reinforcing bar Can be estimated to be 744 ° C (equivalent fire time of 180 minutes), for example, when the measured value of hardness is 260 HV, the heat receiving temperature of the reinforcing bar is estimated to be 527 ° C (equivalent fire time of 90 minutes) Can do.

第３ステップ（Ｓ３）では、鉄筋の受熱温度と残存強度との対応関係に基づいて、上記第２ステップで求めた受熱温度の推定値から鉄筋の残存強度を導き出す。例えば、鉄筋の受熱温度と残存強度との対応関係が図５のグラフで表される場合において、受熱温度の推定値が例えば７４４℃（等価火災時間が１８０分）となったときには、鉄筋の耐力（永久伸びの値を０．２％とする）を４００ＭＰａ、最大強さ（破壊強度）を５００ＭＰａ、破断伸びを３１％とそれぞれ推定することができ、例えば、鉄筋の受熱温度が５２７℃（等価火災時間が９０分）となったときには、鉄筋の耐力を８７５ＭＰａ、最大強さ（破壊強度）を９２５ＭＰａ、破断伸びを１４％とそれぞれ推定することができる。   In the third step (S3), the residual strength of the reinforcing bar is derived from the estimated value of the heat receiving temperature obtained in the second step based on the correspondence between the heat receiving temperature and the residual strength of the reinforcing bar. For example, in the case where the correspondence relationship between the heat receiving temperature of the reinforcing bars and the residual strength is represented by the graph of FIG. 5, when the estimated value of the heat receiving temperature is 744 ° C. (equivalent fire time of 180 minutes), the strength of the reinforcing bars (The permanent elongation value is 0.2%) can be estimated as 400 MPa, the maximum strength (breaking strength) can be estimated as 500 MPa, and the breaking elongation can be estimated as 31%. For example, the heat receiving temperature of the reinforcing bar is 527 ° C. (equivalent When the fire time is 90 minutes), it can be estimated that the proof stress of the reinforcing bar is 875 MPa, the maximum strength (breaking strength) is 925 MPa, and the elongation at break is 14%.

第４ステップ（Ｓ４）では、上記第３ステップで導き出した残存強度に基づいて、鉄筋が再使用可能であるか否かを判定する。すなわち、上記第３ステップで導き出した各推定値と、それに対応する目標性能とを比較したときに、各推定値がすべて目標性能を上回る場合には、その鉄筋は再使用可能と判断することができ、推定値の何れかが要求性能を下回る場合には、その鉄筋は再使用不能と判断することができる。   In the fourth step (S4), it is determined whether or not the reinforcing bar can be reused based on the residual strength derived in the third step. That is, when each estimated value derived in the third step and the corresponding target performance are compared with each other, if all estimated values exceed the target performance, it can be determined that the reinforcing bar is reusable. If any of the estimated values falls below the required performance, it can be determined that the reinforcing bar is not reusable.

以上のように、本実施形態によれば、診断対象となる鉄筋の硬さを測定して、その測定値から当該鉄筋の受熱温度を推定した後、この受熱温度の推定値から当該鉄筋の残存強度を導き出すとともに、この残存強度に基づいて、当該鉄筋が再使用可能であるか否かを判定するようにしたので、従来のような供試体の採取が不要となり、鉄筋コンクリート部材が火災を受けた際に、当該鉄筋コンクリート部材を構成する鉄筋が火災後に再使用可能であるか否かを容易かつ速やかに判定することができる。また、火災を受けた鉄筋コンクリート部材から供試体を採取する必要がなくなることから、補修に要する費用と時間を大幅に縮減することができる。   As described above, according to the present embodiment, after measuring the hardness of a reinforcing bar to be diagnosed and estimating the heat receiving temperature of the reinforcing bar from the measured value, the remaining of the reinforcing bar is estimated from the estimated value of the heat receiving temperature. In addition to deriving strength, it was determined whether or not the rebar could be reused based on this residual strength, so it was not necessary to collect specimens as in the past, and the reinforced concrete member was fired. At this time, it can be easily and promptly determined whether or not the reinforcing bars constituting the reinforced concrete member can be reused after a fire. Moreover, since it is not necessary to collect a specimen from a reinforced concrete member that has received a fire, the cost and time required for repair can be greatly reduced.

なお、本実施形態においては、鉄筋の硬さの測定値から鉄筋の受熱温度を推定した後、この受熱温度の推定値から鉄筋の残存強度を導き出すようにしたが、本発明はこれに限定されるものではなく、例えば、鉄筋の硬さと残存強度との対応関係を予め求めておき、この対応関係に基づいて、鉄筋の硬さの測定値から鉄筋の残存強度を直接導き出すことも可能である。   In this embodiment, after the heat receiving temperature of the reinforcing bar is estimated from the measured value of the hardness of the reinforcing bar, the residual strength of the reinforcing bar is derived from the estimated value of the heat receiving temperature, but the present invention is not limited to this. For example, it is also possible to obtain in advance the correspondence between the hardness of the reinforcing bar and the residual strength, and to directly derive the residual strength of the reinforcing bar from the measured value of the hardness of the reinforcing bar based on this correspondence. .

また、本実施形態においては、鉄筋の残存強度に基づいて、当該鉄筋が再使用可能であるか否かを判定するようにしたが、例えば、当該鉄筋に必要とされる残存強度に対応する受熱温度を予め求めておき、この基準となる受熱温度と、推定した受熱温度との比較により、当該鉄筋が再使用可能であるか否かを判定することも可能である。   Further, in the present embodiment, based on the residual strength of the reinforcing bar, it is determined whether or not the reinforcing bar is reusable. For example, the heat receiving power corresponding to the residual strength required for the reinforcing bar is used. It is also possible to determine whether or not the reinforcing bar can be reused by obtaining the temperature in advance and comparing the reference heat receiving temperature with the estimated heat receiving temperature.

また、鉄筋コンクリート部材を構成するコンクリートが火災後に再使用可能であるか否かを診断する際には、先ず、火災を受けた鉄筋の硬さを測定して、その測定値から当該鉄筋の受熱温度を推定した後、この受熱温度の推定値から当該鉄筋近傍のコンクリートが再使用可能であるか否かを判定するようにすればよい。すなわち、普通強度のコンクリートでは受熱温度が５００℃、また高強度のコンクリートでは受熱温度が３００℃程度を超えると強度低下が顕著になることから、コンクリートの種類と受熱温度さえ分かれば、火災後のコンクリートの再使用を判定する（残存強度を推定する）ことができる。上記方法によれば、例えば、ＦＦ法では判定不能であった高強度コンクリートを使用した場合においても、当該高強度コンクリートが火災後に再使用可能であるか否かを容易かつ正確に判定することができる。   Moreover, when diagnosing whether or not the concrete constituting the reinforced concrete member can be reused after a fire, first, the hardness of the rebar subjected to the fire is measured, and the heat receiving temperature of the rebar is determined from the measured value. After the estimation, it is sufficient to determine whether or not the concrete near the reinforcing bar can be reused from the estimated value of the heat receiving temperature. That is, when the heat receiving temperature is 500 ° C for normal strength concrete, and when the heat receiving temperature exceeds about 300 ° C for high strength concrete, the strength decreases significantly. Reuse of concrete can be determined (estimated residual strength). According to the above method, for example, even when using high-strength concrete that could not be determined by the FF method, it is possible to easily and accurately determine whether or not the high-strength concrete can be reused after a fire. it can.

また、鉄骨鉄筋コンクリート部材を構成する鉄骨が火災後に再使用可能であるか否かを診断する際には、鉄筋の診断方法と同様に、火災を受けた鉄骨の硬さを測定して、その測定値から当該鉄骨の受熱温度を推定した後、この受熱温度の推定値から当該鉄骨の残存強度を導き出すとともに、この残存強度に基づいて、当該鉄骨が再使用可能であるか否かを判定するようにすればよい。この方法によれば、鉄骨鉄筋コンクリート部材が火災を受けた際に、当該鉄骨鉄筋コンクリート部材を構成する鉄骨が火災後に再使用可能であるか否かを容易かつ速やかに判定することができる。   Also, when diagnosing whether or not a steel frame constituting a steel-framed reinforced concrete member can be reused after a fire, as with the method of diagnosing a reinforcing bar, measure the hardness of the steel frame subjected to a fire and measure it. After estimating the heat receiving temperature of the steel frame from the value, the residual strength of the steel frame is derived from the estimated value of the heat receiving temperature, and whether or not the steel frame is reusable is determined based on the residual strength. You can do it. According to this method, when a steel-framed reinforced concrete member receives a fire, it can be easily and quickly determined whether or not the steel frame constituting the steel-framed reinforced concrete member can be reused after the fire.

なお、鉄筋コンクリート部材を構成する鉄筋が火災後に再使用可能であるか否かを診断する際には、例えば、次のような診断装置を使用することも可能である。すなわち、この診断装置は、ＣＰＵ、ＲＡＭ、記憶装置、入力装置および表示装置等を有する周知のコンピュータによって構成されており、記憶装置には、上記ＣＰＵにより実行される各種処理プログラムや制御データ等を記憶する記憶領域の他に、各対応関係（鉄筋の受熱温度と残存強度との対応関係、鉄筋の受熱温度（若しくは残存強度）とビッカース硬さとの対応関係）を関数式あるいはテーブルとして記憶する記憶領域や、鉄筋が再使用可能であるか否かを判定するための判定値等を記憶する記憶領域などが設けられている。   When diagnosing whether or not the reinforcing bars constituting the reinforced concrete member can be reused after a fire, for example, the following diagnostic device can be used. That is, this diagnostic apparatus is constituted by a well-known computer having a CPU, a RAM, a storage device, an input device, a display device, and the like. The storage device stores various processing programs executed by the CPU, control data, and the like. In addition to the storage area to be stored, each correspondence relationship (correspondence relationship between the heat receiving temperature of the reinforcing bar and the residual strength, the correspondence relationship between the heat receiving temperature (or residual strength) of the reinforcing bar and the Vickers hardness) is stored as a functional expression or a table. An area, a storage area for storing a determination value for determining whether or not the reinforcing bar is reusable, and the like are provided.

そして、上記診断装置のＣＰＵは、上記記憶装置に格納された各種処理プログラムを読み込んで実行することにより、鉄筋の硬さの測定値を入力してＲＡＭ等に記憶する処理（入力手段）と、記憶装置に記憶された鉄筋の受熱温度とビッカース硬さとの対応関係に基づいて、鉄筋の硬さの測定値から鉄筋の受熱温度を推定する処理（受熱温度推定手段）と、記憶装置に記憶された鉄筋の受熱温度と残存強度との対応関係に基づいて、受熱温度の推定値から鉄筋の残存強度を導き出す処理（残存強度導出手段）と、導き出した残存強度と記憶装置に記憶された判定値との比較により鉄筋が再使用可能であるか否かを判定する処理（判定手段）とをそれぞれ実行するようになっている。   Then, the CPU of the diagnostic device reads and executes various processing programs stored in the storage device, thereby inputting a measured value of the hardness of the reinforcing bar and storing it in the RAM or the like (input means); Based on the correspondence between the heat-receiving temperature of the reinforcing bar stored in the storage device and the Vickers hardness, a process (heat-receiving temperature estimating means) for estimating the heat-receiving temperature of the reinforcing bar from the measured value of the hardness of the reinforcing bar is stored in the storage device. Based on the correspondence between the heat receiving temperature and the residual strength of the rebar, the process for deriving the residual strength of the reinforcing bar from the estimated value of the heat receiving temperature (residual strength deriving means), and the judgment value stored in the storage device and the derived residual strength And a process (determination means) for determining whether or not the reinforcing bar is reusable by comparing with each other.

上記構成からなる診断装置によれば、鉄筋の硬さの測定値を入力装置から入力することによって、鉄筋コンクリート部材を構成する鉄筋が火災後に再使用可能であるか否かを迅速かつ正確に診断することができる。   According to the diagnostic device having the above-described configuration, the measured value of the hardness of the reinforcing bar is input from the input device, thereby quickly and accurately diagnosing whether or not the reinforcing bar constituting the reinforced concrete member can be reused after a fire. be able to.

本発明に係る鉄筋の診断方法の一実施形態を説明するフローチャートである。It is a flowchart explaining one Embodiment of the diagnostic method of the reinforcing bar which concerns on this invention. 鉄筋コンクリート部材の断面の設定例を示す図である。It is a figure which shows the example of a setting of the cross section of a reinforced concrete member. 図２の各点Ｐ１、Ｐ２、Ｐ３における温度履歴を示すグラフで、等価火災時間を６０分とした場合を示している。The graph which shows the temperature history in each point P1, P2, P3 of FIG. 2 has shown the case where equivalent fire time is 60 minutes. 鉄筋の残存強度および破断伸びと等価火災時間との対応関係を示すグラフで、鉄筋がＳＤ４９０の場合を示している。It is a graph showing the correspondence between the residual strength and breaking elongation of the reinforcing bars and the equivalent fire time, and shows the case where the reinforcing bars are SD490. 鉄筋の残存強度および破断伸びと等価火災時間との対応関係を示すグラフで、鉄筋がウルボン（登録商標）の場合を示している。The graph which shows the correspondence of the residual strength of a reinforcing bar and breaking elongation, and an equivalent fire time, and shows the case where a reinforcing bar is Urbon (registered trademark). 鉄筋のビッカース硬さと等価火災時間との対応関係を示すグラフで、鉄筋がウルボン（登録商標）の場合を示している。A graph showing the correspondence between the Vickers hardness of a reinforcing bar and the equivalent fire time, showing the case where the reinforcing bar is Urbon (registered trademark). 鉄筋のビッカース硬さと受熱温度との対応関係を示すグラフで、鉄筋がウルボン（登録商標）の場合を示している。It is a graph showing the correspondence between the Vickers hardness of the reinforcing bar and the heat receiving temperature, and shows the case where the reinforcing bar is Urbon (registered trademark).

Claims (1)

鉄筋コンクリート部材が火災を受けた際に、当該鉄筋コンクリート部材を構成するコンクリートが火災後に再使用可能であるか否かを診断する方法であって、When a reinforced concrete member receives a fire, it is a method of diagnosing whether or not the concrete constituting the reinforced concrete member can be reused after a fire,
火災を受けた鉄筋の硬さを測定して、その測定値から当該鉄筋の受熱温度を推定した後、この受熱温度の推定値から当該鉄筋近傍のコンクリートが再使用可能であるか否かを判定することを特徴とするコンクリートの診断方法。After measuring the hardness of the fired reinforcing bar and estimating the heat receiving temperature of the reinforcing bar from the measured value, determine whether the concrete near the reinforcing bar can be reused from the estimated value of the heat receiving temperature A method for diagnosing concrete characterized by:
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