Study Of Concrete Quality Testing Methods Base On Ultrasonic CT

At present, a large number of concrete ultrasonic testing methods are qualitative or half-quantitative because of the limit of themselves, and it's very hard to acquire a quantitative result. Recently, thanks to the introducing of CT (Computed Tomography), the concrete inner-quality on tomography surface has been realized fully and accurately by means of image.In this paper the tomography algorithm of concrete by ultrasonic CT is studied. Because the ultrasonic will refraction when it transmiting in concrete, this paper introducing the ray tracing to tomography arithmetic has improved the reconstruction algorithm and acquired satisfactory results.On the basis of analysing the ray tracing algorithm, the LTI (Linear Traveltime Interpolation) Algorithm Based on Scan-cross is put forward by improving. Because of its omni-directional full scan and only one time in the whole area, the low speed area which is in the same line with emission spot is around, the algorithm precision is improved and the programming complexity is reduced. In addition,In the concrete ultrasonic test, due to incomplete sampling data, serious disturbing factors and error, the SIRT algorithm is used to reconstruct concrete and the effect is satisfactory. At the same time, the algorithm to acquire coefficient matrix A is present, which can reduce the computational difficulty greatly.A new concrete ultrasonic CT array testing method is introduced in this paper, which is convenient, practical and applied to various shape concrete. By numerical simulation, it's proved that this method sample track-time data more roundly and the reconstruction effect is better. Finally, the result of numerical simulation shows that make use of the testing method and the reconstruction algorithm in this paper to acquire concrete ultrasonic CT image are feasible and the effect of image reconstruction is satisfactory.