| Abstract: |
Unreinforced brick masonry (URM) is responsible for the lion share of the existing building stock in seismically active regions, such as the W3 region of South Asia, under much of the Mediterranean basin and through a large part of Latin America; indeed, its repeated poor performance (published cases from as early as 1931 [1]) has led to considerable research into earthquake retrofitting. Among these is reinforced concrete (RC) jacketing the placement of a small number of tiles, normally 30–60 mm thick, with well cover combined with welded wire fixed to the wall by steel connectors one of the most popular interventions in developing countries because it’s cheap, uses locally available materials and requires some skill. A systematic review and meta-analysis of experimental and analytical studies published from 1988 to the end of 2024 quantifying seismic behavior of brick masonry walls and buildings retrofitted with RC jacketing is presented. According to PRISMA protocol, a total of 42 studies were included for qualitative synthesis and 28 for quantitative meta-analysis with contributing 61 test specimens. Random-effects meta-analyses on lateral strength improvement ratios provided a pooled estimate of 2.16 (95% confidence interval: 1.87–2.49) with significant heterogeneity (I² = 78%), possibly related to different values and impacts of jacket thickness, mesh reinforcement ratio, anchorage spacing/axial stress level/pre-test damage state. The pooled improvements were 2.80, 1.70, and 4.30 in initial stiffness, displacement ductility, and cumulative energy dissipation, respectively. There were significant biases; in particular, the lack of full-scale dynamic tests and discrepancies or omission of anchorage reporting, along with no data on cost-effectiveness. In the end, the review concludes with design-oriented recommendations and priority research directions for performance-based acceptance criteria and proposes the pooled estimates as first order capacity factors helpful to designing RC jacketed masonry buildings in preliminary phases. |
