151 Theoretical Research and Numerical Simulation for Defects Detection of Concrete with Infrared Thermograph (IRT)

Concrete is the important material for Engineering structure, the method to detect the strength of concrete are different, and the rank of strength are not the same, the important reason is that concrete is similar to Composites, the failure mechanism is original defects damaged and performance deteriorative under the effect of loading and corrosive environment. Because the chaos destroyed by damage concrete, the detection of infrared imaging for concrete defect, will be characterized using fractal dimension and concrete damage and fracture criterion and building a viable platform bridge, and the method to detect concrete defect and the accuracy are the key of research topics, through its theory research and the numerical simulation of finite element heat conduction, demonstrated the feasibility and reliability of the method, established the foundation for the follow-up infrared imaging dimension calculations . The paper analyzes the current technical routes and methods of concrete defect detection and strength test, elaborated the theoretical basis and calculation formula of defective concrete depth that detect from precision advanced infrared thermal image, and through the software of Matlab to simulate the FEM heat as well as the calculate and simulate of defect depth, given the original data. There is a need to explain, also can be defined as the temperature gradient and temperature coefficient of thermal infrared, Comprehensive analysis the shape and borders of defect, this can, from the perspective of three-dimensional to judge availability, size, location, size and extent of defect through infrared thermal imaging technology that high resolution.