Image Analysis Of Crack Width On Continuously Reinforced Concrete Pavement

Because the applications of Continuously Reinforced Concrete Pavement (CRCP) are relatively short time in our country, the long-term performance of CRCP is lack of study. The overseas experiences show that the crack width is the key factor to influence the long-term performance of CRCP. So it is important to study the crack width.If the crack width of CRCP is too wide, the reinforcing bar and the base will be corroded at the crack due to infiltrating rainwater under the influence of environment. The wider transverse crack will cause the loss of load transfer and the concrete spalling at the crack. Then the punchout of CRCP slab will be easily produced under the load wheel. So it is necessary to control the crack width and trace the change of the crack width for a long time. The pavement should be maintained in time if the crack is too wide. Therefore, it must research the simple and effective method of testing and evaluation.According to the character of CRCP, the testing difficulty of crack width with conventional measuring microscope and the urgent demand of the crack testing, the paper puts forward the method of picking and analyzing the crack image with computer image processing technique. On the basis of introducing and analyzing the theory of the digital image processing, the crack width is tested with image processing technique according to the crack image of digital camera. The principle, method and procedure of the crack testing are put forward, and the testing error is analyzed. At the same time, the image processing method and analyzing program are developed with MATLAB. The results show that the program is simple to operate and fast to compute. Therefore, the image processing method instead of conventional measuring microscope testing method may reduce the labor, enhance efficiency of testing and analyzing, and avoid influencing traffic.The paper puts forward to apply extension method in evaluating the crack width in according with the results of CRCP crack width with image processing, and compare to extension method and statistical method. The results of evaluation show that the extension method is more reliable and accurate than statistical method, and it can meet...