This report describes a series of road trials of two proprietary thin surfacing techniques, UL-M (1 site) and Safepave (7 sites), and summarises the performance of the materials during their early service life. Most of the claims for the materials appear to be confirmed, but there are reservations regarding surface texture. Visual surveys on these heavily trafficked sites generally show significant consolidation of material in the wheel-paths; however, low-speed (50 km/h) skidding resistance measured using SCRIM is unaffected and is being maintained at an acceptable level in all cases. Monitoring to date shows generally good integrity and adhesion of the surfacing. However, isolated areas of material loss have been observed, particuarly at junctions, on some Safepave sites where turning vehicles have caused scuffing and pull-out of material. Where Safepave was used on a jointed concrete pavement, the technique of saw-cut and seal at expansion joints appears to be the most effective method for minimising reflective cracking at joints. On some of the flexible construction Safepave sites, no pre-treatment was carried out to cracks in the surface or to other defects and consequently many defects have re-appeared, necessitating further maintenance. Preliminary maintenance and minor repairs prior to the application of Safepave will assist in ensuring maximum life from the new surfacing. (A)
Abstract