ABSTRACT
Highway pavement must suer from various diseases or damages and the service level must be influenced due to repeated wheel wear and influences of such natural factors as icy, rainy or snowy weather. Untimely discovery and improper treatment are bound to shorten the service life and cost a lot of maintenance fees [1-2]. In order to keep the service level and take corresponding measures, we must enhance prevention, maintenance and management of highways and investigate pavement conditions regularly. Undoubtedly, pavement crack is a typical disease. The maintenance fee will be heavily lessened in case that cracks are discovered instantly. So how to investigate the whole pavement fully and figure out the diseases without influences upon normal trac orders has become a challenge to be solved. While traditional methods based on manual visual detection of cracks cannot adapt to fierce development of highways any more. Prior to 1990s, highway administrations adopted unreasonable pavement maintenance schemes for short of systematic data collection and evaluation, scientific maintenance decision management, limited experience and inadequate quantitative evaluation to pavement damages and damage degree, resulting in deterioration of pavement quality and increase of use cost [3-4].
