Assessment of Support Conditions of Concrete Pavement Using FWD Deflection Basin Data

Abstract Results from a field forensic investigation conducted using a falling weight deflectometer (FWD) and visual observations on a jointed concrete pavement that showed premature distresses are presented in this article. At the time of testing, the pavement was six years old and was supported on a crushed limestone granular base underlain by cohesive natural or fill subgrade. The primary objective of the field investigation was to assess whether the foundation support conditions contributed to the distresses observed. FWD tests were conducted on 140 panels over an 830-m-long section of which 25 panels showed distress. The FWD deflection basin data was used to calculate several index parameters, which showed statistically significant differences between the cracked and the uncracked slabs, which suggests that the foundation layer properties were comparatively weaker under the cracked slabs. Visual observations showed that some of the distresses were related to potential lateral movement of the slopes next to the pavement.