|
With the needs of the development of modern engineering and construction technology progresses, large concrete structures are widely used, often in the electricity infrastructure , concrete dams, bridges podium , towering structures , large building foundation . Therefore, the safety of large concrete structures how the performance can be guaranteed , became the subject of another new field of architecture ; how to test lower cost , less damage to the original structure of the request, the right to conduct a comprehensive mass concrete defect detection on become our urgent problem . For large volume concrete quality control, currently used detection method has its own drawbacks and difficult to be widely used. Using ground-penetrating radar to test the internal defects of concrete to meet the requirements of large test distance , test accuracy is decreased with increasing distance ; echo method using a scanning type impact testing, to avoid interference from environmental factors , but the largest size test structures only reach 1.8m; method using ultrasonic testing, due to lack of physical parameters , the general test distance of 2m or less precision to meet the requirements , the test is restricted. Therefore , this paper proposes ultrasonic test mass concrete experimental study of internal defects in the premise of reducing test costs , increase the test distance, improve test can be realized , accurately determine the mass concrete internal defects . Through experimental research, this paper got three innovations , including: ( 1 ) increased to 4m in the ranging process , to ensure the stability of the data obtained under ultrasound test and test distance and the correlation between the strength of concrete , under the proposed large ranging ultrasonic testing theory ; ( 2 ) by ultrasound technique combined with the concrete core drilling method common test method for determining the internal defects , not only reduces the cost of testing , and improve test accuracy ; ( 3 ) the test is based on the in practical engineering studies on the experimental findings and test methods, test for large distance increasing use of ultrasound has very important significance.
|