Evaluation of mortar strength in existing masonry structures through a Minor Destructive Technique

The mechanical characterization of material components in existing masonry structures has been the topic of several research studies. Most of them are currently focusing on mortar, the most difficult material component to characterize, trying to evaluate its strength. To achieve this aim, a good option is performing Minor-Destructive Testing (MDT). A novel MDT technique is investigated in this study, based on the field vane shear test for soils. The instrumentation consists in a four-winged pin (X-Drill) and a torque wrench. The testing procedure consists in inserting the pin in a mortar joint and applying a torque to the pin through the dynamometric key. The dynamometric key records the magnitude of the torque while the pin brings the material to failure. This research presents the results of an experimental campaign based on the comparison between standard tests and X-Drill measurements on different types of mortars.Postprint (published version