Experimental testing of two novel stress sensors for SHM of masonry structures

The paper presents an experimental study on the performance of two types of stress sensor for their possible use in structural health monitoring (SHM) of masonry constructions. Ceramic piezoelectric sensors and capacitive sensors were installed in mortar bed-joints of two series of masonry specimens made of calcarenite stones and clay bricks. The specimens were tested under uniaxial compression, assessing the effectiveness of the sensors in recording the stress state variation in terms of vertical stresses within different types of masonry. Experimental results show that, although both the ceramic and capacitive sensors were initially designed to be embedded in concrete elements, their application in mortar joints ensures a good agreement with records by standard measurement devices. Results also demonstrate the possibility to extend the application of these devices to existing masonry structures, where SHM becomes a challenging issue