Performance of two innovative stress sensors imbedded in mortar joints of new masonry elements

•An experimental study on two new stress sensors for static SHM of new masonry has been carried out;•Ceramic piezoelectric and capacitive sensors were installed in masonry walls and tested in compression;•The proposed stress sensors are low-cost and of easy installation within mortar joints;•Stress measures by sensors were compared with machine load cell measures to test their reliability;•Results showed good accuracy of sensors, validating their possible use for static SHM of new masonries. Many historical cities enjoy the presence of masonry buildings with inestimable historical, artistic and cultural value. Old masonry buildings often suffer structural deficiencies, design faults and materials aging process. In recent years, many researchers focused their attention on the opportunities that structural health monitoring (SHM) can ensure for the health state of existing masonry structures, where damage can be difficult to be promptly predicted, pontentially causing abrupt collapses, with high risks for the community. This paper presents an experimental study on the effectiveness of two types of stress sensor for SHM of new masonry elements. Ceramic piezoelectric sensors and capacitive sensors were installed in mortar joints of two series of specimens made of calcarenite stone masonry and clay brick masonry. All specimens were tested under uniaxial compression with displacement control, to assess the effectiveness of sensors in recording pressure variation within the different types of masonry and therefore testing their potential use for SHM applications. Even though both the ceramic and capacitive sensors were designed as stress sensors for concrete structures, their installation within mortar joints provided a good response, based on the comparison with standard measurement devices. Results demonstrate the suitability of the sensors even for SHM of masonry structures.