Assessment of the Behavior of a Flexible Pavement Under Load Based on Strains Measurements with Fiber Optic Sensors in In-Situ Conditions

Road pavements are made of layers of various materials. In the case of a flexible pavement, it is a system of layers consisting of: a mineral-asphalt mixture (the upper part of the pavement), a sub-base made of an unbound mixture (the layer below the mineralasphalt mixture) and lower layers of the pavement and the improved/unimproved subgrade. The load on the pavement causes stresses and strains in its layers. The values of strains and stresses determine its fatigue life. When designing a road pavement, the values of strains are calculated theoretically, e.g. using software based on constitutive models. The development of measurement technologies allows for an increasingly better assessment of the pavement behavior in real conditions. In particular, recent years have brought great progress in the use of fiber optic sensors to measure strains during the operation of the surface layers. The paper presents the results of tests of a flexible pavement using DOFS (Distributed Optical Fiber Sensors). The tests were carried out on a test section specially prepared for the needs of the research project.