Effectiveness of slab stabilization in mitigating reflective cracking in HMA overlays: a case-history

Slab stabilization is the pressure insertion of a flowable material beneath a concrete slab, in order to restore slab support. The application of such a technique can pose some problems. Therefore, an experimental study has been performed on the start of the runway (turnaround bay) of an Italian airport in order to assess the real capability of different types of slab stabilization techniques to rehabilitate the needed bearing properties. Crack surveys, deflection tests by the FWD and traditional plate bearing tests on the subgrade have been performed prior and after the four types of interventions in order to evaluate the structural effects at the centre, at joints and corners of slabs. The obtained results are useful in assessing the different capability of such rehabilitation strategies to optimise bearing properties and allow to identify the effect in mitigating reflective cracking in asphalt overlay