Measurement on the Strength of Steel in Reinforced Concrete Structure Using the Ultrasonic Pulse-wave Method
碩士 === 國立屏東科技大學 === 土木工程系所 === 97 === The study first established a regression equation of the steel tensile strength and its wave velocity measured by opposite faces. The improved ultrasonic pulse-wave method was then employed to perform surface measurement on reinforced concrete specimens to m...
| Main Authors: | , |
|---|---|
| Other Authors: | |
| Format: | Others |
| Language: | zh-TW |
| Published: |
2009
|
| Online Access: | http://ndltd.ncl.edu.tw/handle/01722315864820919497 |
| Summary: | 碩士 === 國立屏東科技大學 === 土木工程系所 === 97 === The study first established a regression equation of the steel tensile strength and its wave velocity measured by opposite faces. The improved ultrasonic pulse-wave method was then employed to perform surface measurement on reinforced concrete specimens to measure the steel wave velocities CS. The measured values were substituted into the regression equation to obtain the predicted fy values. After the measurement, the specimens were broken. The steel bars were taken out to be measured the wave velocities by opposite faces and to be performed the tensile strength test. The values were then compared with the measured CS by surface measurement and the predicted value fy to evaluate the accuracies of the predicted values.
The test results shows that, the best correlation regression equation is a 2nd order polynomial equation fy=-0.03056966CS2 +314.0110CS-801737. Its correlation coefficient r2=0.959. The applicable range of CS value is in 4900~5200 m/sec. The standard deviations of the measured CS values are only in a range of 4.3~17.4 m/sec. The coefficients of variation are only in 0.87×10-3~3.42×10-3. The error percentages between the measured CS values
and those measured by opposite faces are only in -0.08%~0.65%. The error percentages between the predicted fy values and the tensile strength fy values are less 8%. The results shows the accuracy of the presented method.
|
|---|