紅外線熱影像技術檢測鋼筋混凝土結構物水灰比和中性化深

Inspection on the Water-Cement Ratio and Carbonation Depth of Reinforced Concrete Using Infrared Thermography

郭甫育(Fu-Yu Kuo)

指導教授 ： 吳志興

國立屏東科技大學/工學院/土木工程系所/碩士(2008年)

https://doi.org/10.6346/NPUST.2008.00051

摘要

本研究係採用紅外線熱影像技術中脈波熱影像檢測法，給予鋼筋混凝土試體外部加熱，利用紅外線熱影像儀，記錄不同水灰比試體之熱消散情形，並尋求水灰比對熱消散溫度比的關係，以建立一套評估水灰比的最佳模式。再將此模式應用於實際工程案例上作驗證，並探討影響量測值之因素。另外，用評估之水灰比代入岸谷式來計算鋼筋混凝土結構物之中性化深度，並與鑽心酚酞試驗之中性化深度作比較。
本研究結果顯示，將水灰比WC與熱消散溫度比TR作迴歸分析，以瓦斯噴燈於無鋼筋處之加熱模式所得之相關性最佳，其迴歸式為WC=28.9212TR2-49.4146TR +21.2686 ，相關係數r2為0.986。另依戶外工程案例之試驗結果顯示，清晨及早上時段，因受太陽照射影響大氣溫度上升，使熱消散曲線分別於66和78分鐘時有異常上升現象，致使水灰比或水膠比評估值誤差甚大。正午時段，大氣溫度前後溫差僅2℃，溫度上升較緩和，其評估值誤差不大。而下午及傍晚時段，溫度曲線呈現較穩定降溫，其評估值誤差亦小。利用紅外線評估水灰比配合岸谷式求得中性化結果與鑽心酚酞檢測中性化深度結果誤差僅為0.1 cm，顯示前者之技術具有可行性。

關鍵字

紅外線熱影像技術 ； 脈波熱影像法 ； 水灰比 ； 中性化深度

並列摘要

This study used the pulsed thermography of infrared thermography technology to heat reinforced concrete (RC) specimens, and then used an infrared thermography meter to record the heat dissipation history on specimens of different water-cement ratios WC. The data was used to formulate a best model to evaluate the WC of concrete. The model was then applied on a RC construction for verifying its feasibiltiy. The factors influencing the measurement values were discussed as well. Furthermore, the evaluated WC was also substituted into a Kishitani formula to calculate the carbonation depth of RC structure and compare with that by the phenolphthalein test on drilled concrete cores.
The test results showed that, the best result of the regression analysis of WC vs heat dissipating ratio TR was the model of gas blowtorch heating on the area without steel. The regression equation is WC=28.9212TR2-49.4146TR +21.2686, r2=0.986. The test results of outdoor construction showed that, the heat dissipation curves of early morning and morning times had unusual rise on 66 minutes and 78 minutes respectively, due to sun lighting-up and rising environmental temperature. The evaluated WC or water-binder ratio WB then has large errors. The environmental temperature has 2℃ rising only in the noon time. The environmental temperature rised more smoothly and the error of the evaluated WC is not large. In the afternoon and evening times, the temperature curve decrease stably and the errors of the evaluated WC are also small. Comparing the carbonation depth calculated by substituting the evaluated WC of infrared ray into the Kishitani formula, with that by the phenolphthalein test on drilled concrete cores, the difference of carbonation depth is only 0.1 cm. This result showed the feasibility of the technique.

並列關鍵字

Infrared Thermography Technology ； Pulsed Thermography ； Water-Cement Ratio ； Carbonation Depth

參考文獻

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