Assessment, repair, and retrofitting of masonry structures: A comprehensive review.

In the history of our civilization, masonry structures date back thousands of years. Considering the different types, geometries, and arrangements of masonry components, as well as the mortar properties, defining "masonry" precisely is challenging. Construction of masonry structures relies on layering single components and binding them using mortar or crafting them with stones without mortar. Despite many advantages, masonry structures remain one of the most vulnerable construction types. Many of these structures have not been designed to withstand seismic loads. Generally, their structural systems have been designed primarily to withstand gravity loads. Consequently, moderate earthquakes can cause extensive damage and destroy entire cities. Therefore, the assessment, repair, and retrofitting of these structures is vital to society's well-being. First, this study describes masonry structures and their mechanical and structural characteristics. Next, methods for detecting and classifying common types of damage are presented. Subsequently, a comprehensive review of assessment, repair, and retrofitting methods for masonry structures is provided. Machine learning (ML) techniques have proven to be exceptional tools for providing accurate and reliable information. In this paper, descriptions and recent advances in ML techniques for the assessment, repair, and retrofitting of masonry structures are presented. These models can be utilized for several predictive applications, such as determining possible damage scenarios in heritage buildings, assessing seismic vulnerability, detecting superficial surface damage, and selecting mortar compositions for optimal mechanical properties. Furthermore, structural health monitoring (SHM) methods applicable to masonry structures are discussed. The study concludes with case studies, and an extensive discussion of existing methods, challenges, and recommendations for future work. • Smart materials offer safety and cost benefits for masonry structures. • Retrofitting URMs crucial for climate change resilience. • Post-tensioning discouraged in rural areas due to material quality. • Retrofitting must enhance out-of-plane behavior to reduce earthquake fatalities. [ABSTRACT FROM AUTHOR]