ABSTRACT

Use of micro-milling and thin dense-graded flame-retardant asphalt overlay in long tunnel concrete pavement is a relatively new technique in China. Earlier research showed that the micro-milling quality control is very important for the service life of overlay treatment. This paper proposed a quality control method, using 3D laser scanning technology, to accurately and efficiently recognise the unacceptable micro-milled area. A validation field test was first designed to verify that the micro-milled surface texture of concrete pavement can be accurately acquired by using 3D line laser technology. On the basis of a modified data processing that was proposed to fix data, the 3D micro-milled texture model was established, and then a micro-milling quality control method was proposed. A field test on a micro-milling rehabilitation project of Highway G75 Jiang Junshi tunnel, Sichuan Province, China, was conducted to assess the feasibility of the proposed method. Results demonstrated the proposed method is promising for providing an automatic, accurate and comprehensive assessment of micro-milled surface and for identifying unacceptable micro-milled areas that need to be re-milled. The developed method is quite valuable for reducing the wait time in the field during micro-milling construction operation, which is important for transportation agencies and public drivers.