Determination of Layer Modulus Master Curve for Steel Deck Pavement using Field-Measured Strain Data

Orthotropic steel deck (OSD) bridges have gained increasing popularity around the world during the past 20 years. The steel deck pavement is one of the major components of an OSD bridge and a well-designed pavement is essential to extend the service life of the bridge. To optimize the design method for OSD pavements, this study evaluated the strain responses and the layer moduli of a field OSD pavement under different loading conditions. Firstly, a series of field tests were conducted to measure the strain responses of the OSD pavement. The test results then were analyzed to evaluate the effects of loading speed and temperature on the strain values and response frequencies of the pavement. Secondly, a finite element model of the bridge-pavement system was established to back-calculate the layer moduli of the field OSD pavement from the measured strain data. Based on the back-calculation results, the master curves for the layer moduli of the pavement were determined and validated. These master curves can reflect the actual modulus properties of the field OSD pavement and be used to calculate strain-stress state in the OSD pavement at any temperature as well as loading speed. Thus the critical strain and stress within the pavement can be determined, which should provide the reference for the design of this type of pavement.