A Multi-Phase Hygro-Thermal Model for Wooden Bridge Components Exposed to Solar Radiation

This study demonstrates the modelling assisted long-term monitoring of wooden bridge components with surfaces exposed to solar radiation. An improved multi-phase finite element model is developed to predict the distribution of moisture content, relative humidity and temperature in wood. Hygro-thermal measurements are collected from the monitoring system of the stress-laminated Tapiola Bridge in Finland. The monitoring uses integrated sensors which provide both the relative humidity and the temperature in given locations of the deck, which are compared to the numerical results. The modelling assisted monitoring can help to reduce the maintenance costs of timber bridges, as well as the cost of instrumentation, and to increase the safety