Serviceability and structural performance of asphalt overlays

The serviceability and structural performance of pre-constructed thin asphalt overlays, laid on an existing concrete base, were tested and the correlation between them was observed. Based on the results of present serviceability index readings, the change in serviceability of different types of asphalt concrete was observed and a statistical test was conducted to see if there was a significant change in the present serviceability index of each highway test section. Two present serviceability index measurements and three visual pavement condition surveys were conducted on eastbound and westbound test sections on IH-20 in Atlanta, USA. The results from field tests conducted on thin (100 mm) asphalt concrete overlays on Portland cement concrete pavements indicated that the change in present serviceability index of asphalt concrete is affected by the type of mixture and the aggregate used in the design and the initial condition of the concrete base. A high correlation between structural performance and the serviceability of thin asphalt concrete overlays was observed.