REMOTE MONITORING OF A REHABILITATED CONCRETE HIGHWAY BRIDGE - 5 YEARS OF RESULTS

As part of a major rehabilitation project, embedded instrumentation was installed in a concrete bridge barrier wall to remotely monitor the key physico-chemical parameters influenced by the prevailing environmental conditions. The remote monitoring was part of a broader experimental program, in which different rehabilitation techniques used in the reconstruction of a bridge barrier wall were evaluated in the field and in the laboratory. The barrier wall was instrumented in 1996 with over a hundred embedded sensors for the measurement of temperature, relative humidity, electrochemical potential and longitudinal strain. The data was collected on an hourly basis with 5 data loggers equipped with cellular modems for data transmission. The bridge structure located near Montreal (Quebec) has experienced typical Canadian temperature extremes from -25°C in the winter to +30°C in the summer, several wet-dry and freeze-thaw cycles, as well as severe restrained shrinkage cracking in the new barrier wall at early- age. The paper presents data obtained from five years of remote monitoring of a bridge under harsh climatic conditions. The full evaluation of the long-term performance of the rehabilitation techniques based on corrosion surveys and testing conducted on-site and in the laboratory will be part of a separate paper.