Fiber optic sensors for assessing strains in cold in-place recycled pavements

This study aims to investigate aspects related to the assessment of strains in the body of asphalt pavements that have been cold in-depth recycled utilising foamed asphalt as a stabilisation treatment for base works. For this purpose, the critical tensile strains within the pavement structure were measured using a fiber optic sensor (FOS) system at four different test sites recycled utilising the mentioned technique. Initially, an investigation was undertaken to define the critical fatigue failure locations within the structure of the test pavements where the FOS systems were eventually installed. The measured strains were verified and documented through falling weight deflectometer loading. The collected data were analysed thoroughly. The results of the analysis prove that the recycled material, except for its sustainability characteristics, could be also characterised as a material durable against fatigue failure.