GPR Imaging Of Multilayer Rebar Mesh Structure

Steel reinforcing bars(rebar)are embedded in buildings,bridges,railroads or roadways.This structure not only enhances the building strength but also improving the efficiency of construction.However,the specifications of the rebar in different parts of the project are very strict,and the incorrect use of the rebar will lead to serious engineering quality problems.In addition,the rebar are characterized by corrosion,and corrosion phenomena of different degrees are inevitable during longterm use.These disease problems of the rebar mesh are always threatening the safety of the public.Therefore,rebar condition examination is important to ensure the safety and durability of these structures.In many reported studies,ground penetrating radar(GPR)has been proved effective for the non-destructive detection of single-layer rebar mesh,but for the multi-layer rebar mesh structure commonly used in engineering,the complexity of its electromagnetic propagation structure has made it difficult to perform non-destructive detection of ground penetrating radar.Therefore,the research on the non-destructive detection method of multi-layer rebar mesh has its necessity and urgency.In this paper,a comprehensive investigation on GPR inspection of multilayer rebar mesh structure will be performed from the following aspects: 1)The GPR image denoising enhancement algorithm is improved to enhance the quality of GPR scanning image;2)the auto extraction of upper layer rebar mesh parameters based on 2-D migration algorithm and morphology processing;3)the extraction of bottom layer rebar mesh parameters based on 2-D correlation analysis.Extensive three-dimensional simulations will be conducted using a simulation program based on the Finite-Difference TimeDomain(FDTD)technique.Actual steel bar mesh structures will be developed and utilized for GPR inspection to evaluate and validate the study.