The Use of Embedded Sensors for Long Term Monitoring/Life Cycle Monitoring (LCM) of Relevant Variables in Precast Concrete Elements

Until recently, accurate long-term measurement of strain, temperature, corrosion potential, and other variables in concrete deep foundations and in superstructure elements has been difficult and costly. However, advancements in sensor technology and wireless data transmission has both simplified data acquisition, increased reliability, improved accuracy, and reduced costs. These advances now provide long-term measurements, which can be accessed in real time for in-service structures through a cloud-based system. Owners along with other stakeholders can now document and maintain “cradle to grave” records on their structural assets with respect to pre-stress level, post-tensioning level, corrosion, temperature, and several other variables of interest—load transfer from the super structure to the sub structure and effects from scour, sudden impacts, etc. Based on these measurements, design parameters, changes in loading, the effects of possible extreme events, corrosion rates, and other anomalous data can be evaluated in real time. This process allows owners with sufficient time to plan remedial actions which will prevent or at least minimize the risk of catastrophic failure. This paper discusses two case histories of structures constructed in Florida, including the installation of the system, results from the days of monitoring, and its implications for the future.