Analysis of historic multi-leaf masonry behaviour under compressive load through Digital Image Correlation (DIC)

This research investigates historic multi-leaf masonry with a particular focus on the out-of-plane strains of historic masonry walls subjected to compressive loading. The specimens analyzed consist of two distinct types: three double-curtain walls with noncollaborating layers and three walls with two external curtains and an internal core. The primary objective is to study the behaviour of masonry under compressive load by comparing experimental results obtained using the traditional method of Linear Variable Displacement Transducers (LVDTs) with those derived from the novel technique of Digital Image Correlation (DIC). This comparison aims to identify the failure modes of multi-leaf masonry and to analyze the strains that develop when the walls are compressed. Another key aspect explored in this study are the data acquisition methodologies. Specifically, the research seeks to validate the innovative digital tool, DIC, employed in conjunction with the traditional LVDT method. It assesses the reliability of the DIC results by comparing them with those obtained from LVDTs, highlighting its numerous advantages. Unlike the traditional methodology, DIC, which employs optical cameras, does not require physical contact with the specimen during testing. It provides continuous data throughout the experiment and allows for the measurement of displacements and deformations across the entire specimen, as opposed to the localized areas monitored by LVDTs. Furthermore, this research contributes valuable insights into multi-leaf masonry and failure loads, which are essential for characterizing this type of masonry.