Laboratory Testing and SHM of a Prestressed Concrete Beam Under Accelerated Artificial Corrosion and Sustained Loads

Real-time long-term monitoring can be an essential tool for the continuous assessment of existing and new structures. Numerical modelling of the real behavior of structures requires deep information that can be obtained with a pervasive monitoring accompanied by both field and laboratory testing. Real-time data allows to update the remaining service life estimation, supporting proactive maintenance strategies. Furthermore, the evaluation of the actual bearing capacity and the comparison between resistance and actions within the domain of relevant safety acceptance criteria can be performed with an increased knowledge of the structural performance. This paper presents an experimental study designed to investigate the combined effect of corrosion and sustained loads on a prestressed concrete element. The beam, subjected to a four-point bending test, has a 200 x 300 mm cross section, a total length of 3700 mm and a clear span of 2700 mm. The element was exposed to accelerated corrosion through electrolytic cells for up to 70 days. Asustained load equal to 150 kN, corresponding to approximately 62% of the ultimate load of an identical undamaged reference beam, was simultaneously applied. Aiming to evaluate the structural behavior according to the progress of the damage level, a MEMS technology real-time monitoring system has been set to collect data and analyze the beam response in continuous. A FE model was developed to optimize the monitoring system setup, to predict the behavior and to compare experimental results with numerical simulations.