【摘要】 桥梁、隧道及工业民用建筑的安全监测和质量评价要求对混凝土结构件的内部状况进行无损检测,常规的超声检测仪只给出一维接收声波,直观性差,判读困难,为此开发了一种新的混凝土结构层析成像检测系统。系统中的超声源采用新开发的稀土换能器,可输出大功率的窄脉冲信号,穿过混凝土结构的超声信号由高速并行数据采集电路采集,混凝土结构的内部层析成像计算采用改进的ART快速算法。在混凝土模拟试件的检测中,系统给出的层析成像结果很好地显示出了试件的内部结构,在某高速公路大桥桥墩的强度检测中,测得的低密度区与回弹仪的测量结果一致,说明开发的系统可以直观再现混凝土结构强度分布和内部缺陷。更多还原

【Abstract】 The safety supervision and quality evaluation of bridges,tunnels and buildings require the nondestructive testing of their inner properties.Conventional ultrasonic testing equipment only processes one-dimension signals that it receives,from which it is hard to get a clear description of the concrete structures.So a new ultrasonic-tomography system was developed,a specially designed great power and short pulse ultrasonic emitter was used.The ultrasonic signals passing through the concrete structures were captured by high speed signal acquisition circuit.The inner features of the concrete structures were computed by improved fast ART algorithm.In the detection test of the inner defects of concrete sample,the tomography image produced by the system clearly shows the inner structure of test sample.In another bridge pier intensity test,the new system produces bridge intensity tomography images,which are coincident with the detection results by rebound measurer.The experiment results show that the developed system can reproduce the inner intensity distribution and defects of concrete structure,and can be effectively used for the safety supervision and quality evaluation of concrete construction.7 figs,9 refs.更多还原