Test And Research On Quality Defect Detection Of Precast Concrete Component Structure

In the production process of prefabricated components,common quality problems occur from time to time,which greatly affects the internal quality and safety of prefabricated components.In order to minimize or avoid common quality problems and ensure the internal and external quality safety of precast components,it is the ultimate goal of all people to strictly control the quality of precast concrete components.Therefore,a more scientific and perfect detection technique for the quality defects of precast concrete structures is put forward.The subject is supported by the 13 th five-year national key research and development program "key technology of industrial building inspection and evaluation"(No.2016YFC0701700),and studies the structural quality defects of precast concrete components and the bonding quality of precast concrete exterior surface.The test is divided into internal quality defect detection of precast concrete and exterior surface defect detection of precast concrete.The detection methods adopted include traditional ultrasonic method,phased array ultrasonic method,ground-penetrating radar method,impact echo method and infrared thermal imaging method.The test of internal quality defects included the detection of 2 pieces of prefabricated components with different defects made by the component factory and 4 pieces of prefabricated components with different defects made by the laboratory.The test of exterior defect includes one piece of prefabricated component with 30 different defect zones made by the component factory.By comparing the test data of different detection methods,it is found that phased array ultrasonic method or ground penetrating radar method should be adopted in the detection of internal quality defects of precast concrete.The latter has high detection efficiency and can quickly inspect large prefabricated components to improve the efficiency.Through research and analysis,the detection accuracy and applicability of each detection method are obtained,and the detection methods suitable for different precast concrete quality defects are proposed.The infrared thermal imaging method was used to collect data on time,Angle,position and other influential factors and to analyze the results.It was found that the best time for detection was from 11:00 to 14:00 every day,and the detection angle should be controlled within 30°.Figure 64;Table 24;Reference 51...