Continuous strain monitoring of an instrumented pavement section

ABSTRACT

Classically, measurements on instrumented pavements are performed on site, under known load conditions. In such conditions, data interpretation and modelling of the pavement are relatively easy. However, on-site measurements are time consuming and costly to perform, because they require using a dedicated vehicle and closing the lane to traffic. This paper presents an experiment, where an instrumented bituminous pavement motorway section has been followed by remote monitoring, under normal traffic. The section, instrumented with strain gages, temperature probes and geophones, has been monitored continuously during 18 months. Signal sorting procedures have been developed for reducing the quantity of recorded data, and for analysing the structural response of the pavement, under highly variable loading conditions. The results of the strain gage measurements, made at different depths within the pavement, have shown that the response of the pavement presents large variations with temperature, and in particular, that the degree of bonding between layers can decreases at high temperatures, leading to sliding between pavement layers. The mechanical response of this section has been analysed using a classical multi-layer linear elastic pavement model and also a viscoelastic model. The best predictions have been achieved with the viscoelastic model. Different approaches for describing the behaviour of pavement layer interfaces have also been evaluated.

KEYWORDS:

• Pavement monitoring
• remote monitoring
• strain gage
• geophone
• data acquisition
• pavement modelling
• interface