混凝土於不同環境溫度下力學性質之探討

The Study on the Mechanical Properties of Concrete Under Different Storing Temperatures

10.6299/JHA.2016.3.2.R3.33

翁在龍(Tsai-Lung Weng)；林冠宏(Guan-Hung Lin)；翁詩涵(Shih-Han Weng)；翁偉倫(Wei-Lun Weng)

混凝土 ； 力學性質 ； concrete ； mechanical properties

健康與建築雜誌

3卷2期（2016 / 06 / 01）

33 - 40

繁體中文

背景：火力及核能電廠雖採用重質混凝土構造物，但因長期處於高溫環境下其力學性質是否會受到影響，進而產生安全性問題備受重視，因此在結構物與建築材料設計選擇上必須較一般公共結構物更加嚴謹。目的：比較重質混凝土與常重混凝土，長期處於較高溫度環境下(約 95℃) 與常溫下(23℃) 其力學性質之差異變化。方法：本研究將混凝土試體放於水中養護28 天以後，分別貯存於室溫及95℃之溫度環境下，至貯存時間 91 天後，再進行各項力學性質試驗。比較重質混凝土（約 3300 kg/m3）與一般傳統混凝土（約2350 kg/m3）之差異。試驗項目含抗壓強度、劈裂強度、彈性模數。結果：重質混凝土(H 組) 與常重混凝土(C 組) 於貯存環境溫度95℃之抗壓強度、劈張強度及彈性模數，分別為常溫環境(23℃) 下之99~111%、70~98%、及83~107%。結論/ 實務應用：本研究試驗結果顯示混凝土貯存於室溫及95℃之溫度環境下的力學性質差異很小，提供營建構造物設計者參考。

Background: Fossil-fuel and nuclear power plants are constructed using heavyweight concrete. However, their mechanical properties may alter after prolonged periods in high-temperature environments, which is a safety issue. Thus, the design and materials in such structures must be chosen more carefully than with general public buildings. Purposes: The objective of this study was to compare the mechanical properties of heavyweight and normal concrete after prolonged periods in a high-temperature environment (approximately 95°C) and a normaltemperature environment (23°C). Methods: Concrete specimens that were wet-cured for 28 days were placed in environments at room temperature and at 95°C for 91 days before mechanical tests for compressive strength, splitting tensile strength, and elasticity were administered. The properties of the heavyweight concrete (approximately 3,300 kg/m^3) and normal concrete (approximately 2,350 kg/m^3) specimens were compared. Results: The compressive strength, splitting tensile strength, and moduli of elasticity of the heavyweight concrete (H group) and normal concrete (C group) specimens stored at 95°C were 99~111%, 70~98%, and 83~107% that of the specimens at room temperature (23°C). Conclusions/Implications for Practice: The results of this study indicate that the mechanical properties of the concrete and room temperature at 95°C show little difference. The results provide reference for architects.