以不同檢測方法測定混凝土動彈性模數

Abstract

本論文主要研究目的是利用四種不同檢測法來測定混凝土之動彈模數，其中包括超 音波檢測法、敲擊回音法、MTS(material testing system)材料試驗法及振動訊號檢測理 論法，各測得普通混凝土版及高性能混凝土版之動彈性模數(dynamic Young*s modulus) ，並將動彈性模數導入SAP90套裝軟體中進行數值分析，所分析出之自然頻率，再與混凝 土版進行的振動量測試驗做比較，以驗証各種檢測法測定動彈性模數之可行性及可靠性。 研究結果顯示此四種檢測法所測定之動彈性模數，經數值分析後數值解與實驗值之差 值，除了MTS材料試驗法量測動彈性模數的差值為6.2%較高以外，其餘差值均在5％以內， 且以敲擊回音法，量測高性能混凝土動彈性模數之差異值為最低約1.7％，因此以敲擊回 音法，來測定混凝土動彈性模數是可行的。 Three different approaches were used in this thesis to measure the dynamic You ng*s modulus of the concrete, both in the plate and cylinders drilled from the plate .Including the ultrasonic pulse velocity method, the impact -echo metho d, and test of stress-strain curve,both normal strength concrete plate and hig h-performance concrete plate were test by these methods. These dynamic Young* s modulus were used to calculate vibration frequency of plate by SAP90 and com pare with the result from the modal testing.The difference of these approaches with modal testing have a larger value of 6.2% from stress-strain curve test and a smaller value of 1.7% from the impact each method . The variations from impact-echo method are very small . All of these results shows Impact-echo met hod can measure dynamic Young*s modulus of concrete very well.