Because of the need of rapid detection of internal defects and embedded object in concrete structures, a detecting method with linear array probes is presented here, which is the high-resolution and efficient imaging technique for concrete structures by combining with synthetic aperture focusing technique (SAFT). Firstly, array simulation data are processed to be amalgamated B-scan data of concrete structures according to the structural characteristics of linear array; And then the B-scan data are reconstructed in the light of geometrical relation of ultrasonic path and SAFT; At last, the structural imaging figure are calculated. It can be shown from simulation results that the method is effective, and the embedded object in model can be identified effectively.

No abstract

Colloid mill or high-speed shearing mechanical is used in traditional preparation technology of SBS modified asphalt for the dispersion of SBS in matrix asphalt, which leads to the high equipment cost in production of SBS modified asphalt. The fractions oil of FCC slurry oil distillation with a high content of aromatics is a good swelling agent of SBS. The FCC distillation residual (FR) with high softening point can resolve the problem that penetration increased when the addition of swelling agent increased. SBS is pre-swelled by the heavier fractions from FCC slurry oil, and then it will be dispersed in the vacuum residuum (VR) by simple mechanical stirring to prepare SBS modified asphalt due to the perfect swelling effects in this work. The influences of different materials, distillation yield and ratio of FR to VR on the performance of SBS modified asphalt have been investigated. Fluorescence microscopy was applied to observe the different disperse images of SBS modified asphalt prepared by simple mechanical stirring and high speed shearing. The results indicated that the novel method can be used to prepare SBS modified asphalt with good performance and storage stability.