INNOVATIVE SURFACING FOR A LOCAL ROAD

摘要

A severely cracked and distressed pavement was rehabilitated using a conventional 10 mm dense-graded asphalt and a purpose designed 10 mm stone mastic asphalt. These were both placed in layers of about 40 mm thickness over a 14 mm dense-graded asphalt which provided a 30 mm regulation layer. The laboratory evaluation of the purpose designed 10 mm stone mastic asphalt, suggested that this mix should have superior crack resistance as well as providing adequate rut resistance. The site was inspected four times after rehabilitation from January 2005 to October 2005 and the following observations were made. 1. Both longitudinal and transverse cracks appeared in the control section within five months. These were relatively minor in extent and severity compared to the original distress. However, there was some evidence to suggest that the cracks were lengthening and widening with time. 2. No cracks could be found in the experimental section. 3. Some minor surface blemishes in both sections were noted and it is unlikely that these will affect the performance of the trial. 4. The surface texture of the experimental section was significantly coarser than the control section as was expected given the differences in mix designs. The experimental mix section had some variability in the surface texture and this should be monitored to determine if it will affect the long term performance of the mix. 5. The roughness of pavement has been improved by the construction of the trial. In summary, the rehabilitation works have significantly improved the shape, roughness and visual appeal of the road. Reflected cracking has been observed in the control section but none could be found in the experimental mix section.