Research On Infrared Detection Technology Of Concrete Based On Image Processing

In the process of concrete pouring and service,its surface and interior are prone to form defects due to poor construction technique,the action of temperature,humidity and external force as well as the property of shrinkage and creep.As a resault,the working performance steps down.How to detect the defects in concrete scientifically and efficiently has become a hot topic in the engineering and academic circles.Infrared thermal image detection is widely used in nondestructive testing of materials because of its convenience and quickness.However,the concrete material is a bad conductor so that the infrared thermal image detection method is not high in precision and the use range is not wide.On the basis of infrared thermal imaging nondestructive testing technology,this paper combines theoretical research,experimental analysis and digital image processing technology.And the research of infrared detection technology of concrete based on enhanced image processing was carried out according to the technology roadmap.The main research contents are as follows:(1)A method combining image enhancement with infrared thermal imaging is proposed to detect internal defects of concrete by summarizing the current research of detecting methods,infrared thermal imaging technology and digital image processing technology.And related theories and technical principles are expounded.(2)The internal defect detection test of concrete based on radiant heat was carried out.In this experiment,surface of concrete with different types of internal defects was heated by pulse heating and daylight heating,so as to study the changes of surface temperature and the reflection of internal defects in the process of cooling(pulse heating)and heating(daylight heating).The test verifies the effectiveness of infrared thermal image method in the detection of internal defects of concrete under different heating conditions,and the imaging law of the internal defects of concrete and the influence of different heating methods and defect types on the detection results are obtained as well as the maximum detection depth is preliminarily determined by comparing the detection results in order to select fittable heating method according to the actual situation.At the same time,some problems found in the process of detection were sorted out and summarized to provide a basis for the optimization of detection results and data analysis.(3)Algorithm optimization for the problems exposed by infrared detection was carryied out.By combining image reconstruction,image transformation,boundary correction,histogram equalization and other digital image processing methods,the results of each group of tests were optimized,which improved the recognition effect of internal defects of concrete,increased the effective detection depth,and made the reflection of defect contour more accurate.Through the evaluation of optimization effect,the effects of different kinds of algorithms under different detection conditions are obtained,and the application scope and limitations are clarified.