Improved laboratory laser scanning setup and test procedure for 3-D pavement texture measurement

• Each scanned area by commercial laser scanners is too small for pavement studies. • A setup was proposed to provide larger and accurate pavement texture images. • Reverse-twin scanning procedure was proposed to reduce occlusion effects. • Software application was developed for efficient implementation of the new setup. • Experimental verification confirmed the efficiency and accuracy of the new setup. Commercial laser scanners that have the required measurement resolutions, cover too small an area per scan for pavement texture studies. Time and skill demanding image splicing tends to introduce errors. To overcome the limitation, this study developed the laboratory Chang’an University 3D Laser Scanning Device (CUSD) to cover a single-scan area of up to 800 x 325 mm, with the capability to perform a reverse-twin scanning procedure to reduce occlusion effects. To verify the advantages of CUSD, twelve asphalt mixtures were tested by CUSD and a commercial scanner AMES HD9400. CUSD took 19 minutes to scan and process the image of an area measuring 750 mm long, compared to more than 3 hours by AMES HD9400. The experimental verification showed that the mean profile depth (MPD), root-mean-square height (RMS) and height deviation index (R a ) obtained from CUSD images were all within 5% of the values by AMES HD9400.