STRENGTH EVALUATION OF SEWER LINER MATERIALS VIA ULTRASONIC TESTING

摘要

To determine the tensile strength of homogeneous and quasi-homogeneous materials, pulling dog-bone coupon is the traditional method. For the in-situ formed composite material, such as the underground sewer pipe liner, the tensile test samples are obtained from an extra section at the end of the formed liner instead of the major body of the liner. Unless the resin forming process is totally controlled, any mixing mistake will result in an unpredictable strength pattern in the pipe liner. Ultrasonic testing has been correlated to measure the strength of these materials nondestructively. After several tests and modifications, the measurements show that the ultrasonic testing on sewer pipe liner strength evaluation is quite applicable and reliable. This practice allows the engineer to get the liner strength reading right at the job site without long term waiting for the test results from the laboratory. Through scanning, furthermore, the UT reading also can point out any weak portion of the pipe liner, and the workers can reinforce the liner immediately as needed. This paper will discuss the study of the ultrasonic testing method on the sewer pipe liner strength analysis.