Abstract:
The purpose of this study is to set an initial road smoothness specification for asphalt concrete overlaid roads in Sri Lanka and to find out the road roughness when the road satisfies the regularity requirement which is given in the Standard Specifications for Construction and Maintenance of Roads and Bridge (SSCM)Published in 989. Numbers of newly asphalt overlaid roads in various parts of Sri Lanka were surveyed using Vehicle Mounted Bump Integrators and corresponding International Roughness Indices (IRI)were derived. The change of roughness for a short period was also observed. Asphalt overlaid roads with various undulations were surveyed for roughness with Bump Integrator (BI)and the same locations were run with straight edge to measure bump and dip. Smoothness specifications which are currently in use in other countries are taken into consideration. The outcome of roads of those countries as a result of setting a smoothness target is also discussed. This study revealed that it is practical to set an initial roughness value in terms of IRI when the roughness is measured with B a n d the roughness does not change drastically in a short period. Also, it is revealed that the maximum tolerance of surface regularity given the SSCM published in 1989 results a higher IRI value. v
