Study On Nondestructive Detection Technique Of Semi Rigid Base Strength

With the rapid development of highway construction, it has been very difficult to adapt traditional coring testing of semi-rigid base to high standard and efficiency of highway construction. And some destructive tests such as coring destroyed base structure and formed damaged weak surface.Therefore, this article aimed at the existing problems of semi-rigid base strength test and has conducted the system research work to study the problems of the principle of non-destructive testing technology, nondestructive detection technology and detection method of semi-rigid base strength, semi rigid base of nondestructive testing factors etc. The main contents are as following:(1) Analyzed the principle of nondestructive testing technology for reference. Used the nondestructive testing techniques and methods of cement concrete for reference and combined with the characteristics of semi-rigid-base’s strength, This paper proposed the method to detect base’s strength coupling controlled by ultrasonic velocity and basic density, and established a semi rigid base strength nondestructive evaluation model.(2) Study on semi rigid base strength nondestructive testing equipment. Referencing cement concrete strength nondestructive detection method and apparatus and deriving formula of semi rigid base strength based on multi variable expression, determined the suitable equipment and combined detection method of semi rigid base.(3) Study on semi rigid base strength nondestructive detection of impact factors and significant. The research results show that coarse aggregate maximum effects test results, so it must be corrected in ultrasonic testing. Secondly, temperature and humidity and the coupling state also has a great influence on the test results. Based on the factor analysis, we proposed the correction method and principle about detection results according to the fuzzy analytic hierarchy process.(4) The entity engineering application research. On the basis of lab research, we select the typical sections to make the entity engineering verification. Through making the nondestructive testing on the semi-rigid base core sample of Changping Expressway, on-site and core sample of Yingsong highway new-built base course and Fusong to Baishan repair section semi-rigid base of national highway G201, it proved the feasibility and applicable conditions of nondestructive detection method basing on ultrasonic. It put forward that the relative standard error of controling the field ultrasonic testing is ≤20% and the relative standard error of lab ultrasonic testing on core specimens is≤14%.