in the range of theory, and the value from the second experiment is 0.16 which also comes under the range of theory. In case of specimen no.1, there was an error of 12.6% but the Poisson's ratio is highly appropriate. From this, we can analogize the Poisson's ratio has nothing to do with strength, but is related to the materials.
4. Shear Modulus ofElasticity
‣ Theoretical Value
Density of steel 7800
Poisson’s ratio 0.32
The resultant data(velocity) = 5666.7
From this formula, we could determine the modulus ofelasticity,
Theoritical value of E of steel is 200GPa, error would be
Fig.1 Property of materials.
2. Considerations
We could figure out material's properties and method of finding defect of the specimen. Ultrasonic wave value was alm
design
③Mixing the cement
④Produce specimen
⑤Humidity curing
Ⅱ. test description
① Grind the specimen surface
② Strain Gage establishment
③ Measuring creep and shrinkage
④ Measuring strength
◎ Tension strength
- Theoretical value: => 2.12MPa< <3.45MPa, =27.6
- Experimental value:
■ Result discussion
High content of water caused lower strength
2.7 Shrinkage
- Theoretical value: (a=35, : Maximum Shrinkage Strain Ratio)
- The process of finding 'a'
1. Arranging excel data
2. Finding 'a' with using a grapher program
(Converting Excel data into graph shape)
(Standardization of graph through regression analysis)-회귀분석을 통한 그래프 평균화
(Finding 'a' with using shrinkage equation)
3. Finding 'a'
-결과 및 토의
1. 압축강도 실험 중 첫 번째 실험은 12.6% 만큼 강도가 작게 발현 되었으나 두 번째 실험에서는 0.8%의 오차로 이론값과 매우 가깝게 나왔다. 같은 콘크리트를 썼으나 이렇게 두 실험에 차이가 나는 원인은 다짐 문제이다. 실험 당일 각 공시체마다 다른 사람이 다짐을 해서 약간의 차이가