Strengthening of unreinforced masonry

A systematic review of mechanical performance gains and limitations of reinforcement systems

Authors

  • Isaac Sérgio Araújo de Brito University of Pernambuco image/svg+xml
  • Victor Marcelo Estolano de Lima University of Pernambuco image/svg+xml
  • Tiago Ancelmo de Carvalho Pires de Oliveira Federal University of Pernambuco image/svg+xml
  • Emilia Rahnemay Kohlman Rabbani University of Pernambuco image/svg+xml

DOI:

https://doi.org/10.17271/23188472149120266364

Keywords:

Unreinforced masonry, Structural strengthening, Shear strength, Systematic literature review

Abstract

Objective – To systematically analyze reinforcement techniques applied to unreinforced masonry, focusing on gains in mechanical strength, particularly compressive and shear resistance, as well as on the limitations associated with the different reinforcement systems reported in the scientific literature.
Methodology – A Systematic Literature Review was conducted based on a predefined search protocol, clear inclusion and exclusion criteria, and the application of the PRISMA method for study selection. The selected articles were analyzed according to masonry type, reinforcement technique, experimental configuration, percentage gains in strength, and reported limitations
Originality/Relevance – This study addresses a relevant gap in the literature by providing a comparative and integrated synthesis of mechanical performance gains and technical limitations of the main reinforcement systems applied to unreinforced masonry, supporting a critical assessment of their structural effectiveness and practical applicability.
Results – The results indicate that the highest strength gains are predominantly associated with in-plane shear loading, especially for systems based on textile- or fiber-reinforced mortars, such as TRM and FRCM, with increases frequently exceeding two hundred percent. Gains in compressive strength were generally more moderate and mainly related to confinement mechanisms. The most recurrent limitations include performance variability, premature failure at the reinforcement–substrate interface, chemical incompatibility, and restrictions on application in historic masonry.
Theoretical/Methodological Contributions – The study consolidates a comparative framework relating mechanical performance and technical limitations of reinforcement systems and highlights the need for more suitable design models for systems based on inorganic matrices.
Social and Environmental Contributions – The findings support the selection of reinforcement solutions that are more compatible with existing and historic buildings, contributing to safer, more durable interventions aligned with sustainability and built heritage conservation principles.

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References

ALJABERI, Z.; MYERS, J. J. Influence of Near-Surface Mounted (NSM) FRP with cementitious material on the Out-of-Plane Behavior of Reinforced Masonry Walls. 8th International Structural Engineering and Construction Conference 1 jan. 2015. DOI: 10.13140/RG.2.1.1348.9363

ALMEIDA, J. A. P. P.; PEREIRA, E. B.; BARROS, J. A. O. Assessment of overlay masonry strengthening system under in-plane monotonic and cyclic loading using the diagonal tensile test. Construction and Building Materials, v. 94, p. 851–865, 24 jul. 2015. DOI: 10.1016/j.conbuildmat.2015.07.040

ANGIOLILLI, M. et al. Fiber Reinforced Cementitious Matrix (FRCM) for strengthening historical stone masonry structures: Experiments and computations. Engineering Structures, v. 224, p. 111102, dez. 2020. DOI: 10.1016/j.engstruct.2020.111102

ANGIOLILLI, M.; GREGORI, A.; CATTARI, S. Performance of Fiber Reinforced Mortar coating for irregular stone masonry: Experimental and analytical investigations. Construction and Building Materials, v. 294, p. 123508, ago. 2021. DOI: 10.1016/j.conbuildmat.2021.123508

BABAEIDARABAD, R. et al. Seismic retrofit of URM-infilled RC frames by the steel-jacketed hybrid walls. Engineering Structures, v. 291, p. 116438, set. 2023. DOI: 10.1016/j.engstruct.2023.116438

BERNAT-MASÓ, E.; GIL, L. Assessing the performance of CFRP strengthening on masonry walls using experimental modal analysis. Engineering Structures, v. 193, p. 184–193, 17 maio 2019. DOI: 10.1016/j.engstruct.2019.05.036

BERTOLESI, E. et al. Effectiveness of textile reinforced mortar (TRM) materials in preventing seismic-induced damage in a U-shaped masonry structure submitted to pseudo-dynamic excitations. Construction and Building Materials, v. 248, p. 118532, jul. 2020. DOI: 10.1016/j.conbuildmat.2020.118532

BITAR, R. et al. Strengthening unreinforced masonry walls using natural hemp fibers. Journal of Building Engineering, v. 30, p. 101253, jul. 2020. DOI: 10.1016/j.jobe.2020.101253

BORRI, A. et al. Masonry wall panels with GFRP and steel-cord strengthening subjected to cyclic shear: An experimental study. Construction and Building Materials, v. 56, p. 63–73, abr. 2014. DOI: 10.1016/j.conbuildmat.2014.01.056

ANUHYA, C. L. et al. Compression behaviour of brick masonry strengthened with Textile Reinforced Concrete (TRC) – A preliminary study. IOP Conference Series Materials Science and Engineering, v. 577, n. 1, p. 012053–012053, 1 nov. 2019. DOI: 10.1088/1757-899X/577/1/012053

CAROZZI, F. G. et al. Ancient masonry arches and vaults strengthened with TRM, SRG and FRP composites: Experimental evaluation. Composite Structures, v. 187, p. 466–480, mar. 2018. DOI: 10.1016/j.compstruct.2017.12.075

CASSESE, P. et al. In-plane shear behaviour of adobe masonry wallets strengthened with textile reinforced mortar. Construction and building materials, v. 306, p. 124832–124832, 1 nov. 2021. DOI: 10.1016/j.conbuildmat.2021.124832

CASTRO, A. A. B. DA C. et al. Morphological Aspects and Quality of Urban Life. Revista Nacional de Gerenciamento de Cidades, v. 12, n. 85, 27 jun. 2024. DOI: 10.17271/23188472128520244213

COLOMBO, M. et al. Fibre reinforced mortar application for out-of-plane strengthening of schist walls. Construction and Building Materials, v. 121, p. 185–197, set. 2016. DOI: 10.1016/j.conbuildmat.2016.05.158

CORRADI, M. et al. Shear strengthening of wall panels through jacketing with cement mortar reinforced by GFRP grids. Composites Part B: Engineering, v. 64, p. 33–42, ago. 2014. DOI: 10.1016/j.compositesb.2014.03.022

DE SANTIS, S. et al. Out-of-plane seismic retrofitting of masonry walls with Textile Reinforced Mortar composites. Bulletin of Earthquake Engineering, v. 17, n. 11, p. 6265–6300, 9 set. 2019. DOI: 10.1007/s10518-019-00701-5

DE SANTIS, S. et al. Seismic performance of masonry walls retrofitted with steel reinforced grout. Earthquake Engineering & Structural Dynamics, v. 45, n. 2, p. 229–251, 16 set. 2015. DOI: 10.1002/eqe.2625

DEMAJ, A. et al. Shear performance of brick masonry walls reinforced with twisted steel bars. Structures, v. 58, p. 105579, dez. 2023. DOI: 10.1016/j.istruc.2023.105579

DINÇ-ŞENGÖNÜL, B. et al. Behavior of grout injected solid stone masonry walls under in-plane loading. Structures, v. 58, p. 105411, dez. 2023. DOI: 10.1016/j.istruc.2023.105411

DONG, Z. et al. Strengthening of unreinforced masonry walls against out-of-plane loads using carbon textile reinforced mortar optimized by short PVA fibers. Engineering Structures, v. 227, p. 111433–111433, 1 nov. 2020. DOI: 10.1016/j.engstruct.2020.111433

ELMALYH, S. et al. Shear Strength of Unreinforced Masonry Walls Retrofitted with CFRP. Advances in Science, Technology and Engineering Systems Journal, v. 5, n. 2, p. 351–359, 2020. DOI: 10.25046/aj050246

FERRARA, G. et al. Shear capacity of masonry walls externally strengthened using Flax-TRM composite systems: experimental tests and comparative assessment. Construction and Building Materials, v. 261, p. 120490, nov. 2020. DOI: 10.1016/j.conbuildmat.2020.120490

FOLHA DE PERNAMBUCO. Prédios tipo caixão e desabamentos no Recife. Disponível em: https://www.folhape.com.br/noticias/predios-caixao-desabamento/409450. Acesso em: 9 jan. 2025.

GATTESCO, N.; BOEM, I. Experimental and analytical study to evaluate the effectiveness of an in-plane reinforcement for masonry walls using GFRP meshes. Construction and Building Materials, v. 88, p. 94–104, jul. 2015. DOI: 10.1016/j.conbuildmat.2015.04.014

GONEN, S. et al. Stochastic discontinuum analysis of unreinforced masonry walls: Lateral capacity and performance assessments. Engineering Structures, v. 238, p. 112175, jul. 2021. DOI: 10.1016/j.engstruct.2021.112175

HABIEB, A. B. et al. Seismic Retrofitting of Indonesian Masonry Using Bamboo Strips: An Experimental Study. Buildings, v. 13, n. 4, p. 854, 24 mar. 2023. DOI: 10.3390/buildings13040854

HUNG, C.-C. et al. Comparative studies on in-plane shear behavior of masonry wallettes retrofitted with mortar, UHPC, and ECC ferrocement: Shotcrete and prefabricated panels. Case Studies in Construction Materials, v. 21, p. e03801–e03801, 27 set. 2024. DOI: 10.1016/j.cscm.2024.e03801

ISMAIL, N.; INGHAM, J. M. In-plane and out-of-plane testing of unreinforced masonry walls strengthened using polymer textile reinforced mortar. Engineering Structures, v. 118, p. 167–177, jul. 2016. DOI: 10.1016/j.engstruct.2016.03.041

JAFARI, A. et al. Effect of the FRP sheet’s arrays and NSM FRP bars on in-plane behavior of URM walls. Journal of Building Engineering, v. 20, p. 679–695, 20 set. 2018. DOI: 10.1016/j.jobe.2018.09.018

JAFARIAN, S. et al. Performance of low-carbon textile-reinforced mortar: Out-of-plane response of strengthened masonry walls. Construction and Building Materials, v. 415, p. 134904, fev. 2024. DOI: 10.1016/j.conbuildmat.2024.134904

JOO HA LEE. Compressive and Shear Behavior of Masonry Reinforced with Ultra-Rapid-Hardening Fiber-Reinforced Mortar (URH-FRM). Materials, v. 15, n. 24, p. 8825–8825, 10 dez. 2022. DOI: 10.3390/ma15248825

KAFODYA, I.; OKONTA, F.; KLOUKINAS, P. Role of fiber inclusion in adobe masonry construction. Journal of Building Engineering, v. 26, p. 100904, nov. 2019. DOI: 10.1016/j.jobe.2019.100904

KOURIS, L. A. S.; TRIANTAFILLOU, T. C. State-of-the-art on strengthening of masonry structures with textile reinforced mortar (TRM). Construction and Building Materials, v. 188, p. 1221–1233, nov. 2018. DOI: 10.1016/j.conbuildmat.2018.08.039

LOURENÇO, P. B. Monuments and Historic Buildings: Monuments and Historic Buildings: Earthquakes and Structural Engineering. World Congress on Civil, Structural, and Environmental Engineering, abr. 2022. DOI: 10.11159/icsect22.002

MARCARI, G.; BASILI, M.; VESTRONI, F. Experimental investigation of tuff masonry panels reinforced with surface bonded basalt textile-reinforced mortar. Composites Part B: Engineering, v. 108, p. 131–142, jan. 2017. DOI: 10.1016/j.compositesb.2016.09.094

MÉLO, Mauro José Araújo Campelo de. Análise de laudos emitidos sobre "prédios tipo caixão" da região metropolitana de Recife : causas apontadas para os desabamentos e interdições. 2007. 167 f. Dissertação (Mestrado em Engenharia Civil) - Universidade Católica de Pernambuco, Recife, 2007.

MESSALI, F.; METELLI, G.; PLIZZARI, G. Experimental results on the retrofitting of hollow brick masonry walls with reinforced high performance mortar coatings. Construction and Building Materials, v. 141, p. 619–630, jun. 2017. DOI: 10.1016/j.conbuildmat.2017.03.112

MEZREA, P. E. et al. Diagonal tensile tests on historical brick masonry wallets strengthened with fabric reinforced cementitious mortar. Structures, v. 33, p. 935–946, out. 2021. DOI: 10.1016/j.istruc.2021.04.076

MIRABI BANADAKI, H.; ESLAMI, A.; RONAGH, H. Near-surface-mounted retrofitting of damaged/undamaged adobe walls using steel bars: Analytical evaluation of experimental results. Structures, v. 28, p. 2111–2121, dez. 2020. DOI: 10.1016/j.istruc.2020.10.020

OLIVEIRA, R. A. et al. Structural performance of unreinforced masonry elements made with concrete and horizontally perforated ceramic blocks – Laboratory tests. Construction and Building Materials, v. 182, p. 20–34, set. 2018. DOI: 10.1016/j.conbuildmat.2018.06.092

PAGE, M. J. et al. The PRISMA 2020 statement: An updated guideline for reporting systematic reviews. British Medical Journal, v. 372, n. 71, 2021.

PINHO, F. F. S.; LÚCIO, V. J. G.; BAIÃO, M. F. C. Experimental analysis of rubble stone masonry walls strengthened by transverse confinement under compression and compression-shear loadings. International Journal of Architectural Heritage, v. 12, n. 1, p. 91–113, 20 nov. 2017. DOI: 10.1080/15583058.2017.1377314

PRECIADO, A. et al. Seismic damage and retrofitting identification in unreinforced masonry Churches and bell towers by the september 19, 2017 (Mw = 7.1) Puebla-Morelos earthquake. Engineering Failure Analysis, v. 118, p. 104924, dez. 2020. DOI: 10.1016/j.engfailanal.2020.104924

RANJAN, N. et al. Exploring applicability of recycled nylon fiber reinforced mortar in joints and plaster to enhance the bond strength, in-plane and out-of-plane capacity of masonry structures. Journal of Building Engineering, v. 72, p. 106744, ago. 2023. DOI: 10.1016/j.jobe.2023.106744

RAO, K. S. N.; PAVAN, G. S. FRP-Confined Clay Brick Masonry Assemblages under Axial Compression: Experimental and Analytical Investigations. Journal of Composites for Construction, v. 19, n. 4, p. 04014068, ago. 2015. DOI: 10.1061/(ASCE)CC.1943-5614.0000525

ROGIROS ILLAMPAS et al. Validation of the repair effectiveness of clay-based grout injections by lateral load testing of an adobe model building. Construction and Building Materials, v. 153, p. 174–184, 17 jul. 2017. DOI: 10.1016/j.conbuildmat.2017.07.054

SANDOVAL, O. J. et al. Performance of unreinforced masonry panels strengthened with mortar overlays reinforced with welded wire mesh and transverse connectors. Construction and Building Materials, v. 267, p. 121054–121054, 14 out. 2020. DOI: 10.1016/j.conbuildmat.2020.121054

SILVA, L. F. C. DA et al. Sistema de Indicadores de Sustentabilidade Urbana para Pequenas Cidades. Revista Nacional de Gerenciamento de Cidades, v. 12, n. 87, 26 dez. 2024. DOI: 10.17271/23188472128720245181

SOLEYMANI, A. et al. In-plane shear strengthening of traditional unreinforced masonry walls with near surface mounted GFRP bars. Construction and Building Materials, v. 367, p. 130362, fev. 2023. DOI: 10.1016/j.conbuildmat.2023.130362

SPINELLA, N.; COLAJANNI, P.; RECUPERO, A. Experimental in situ behaviour of unreinforced masonry elements retrofitted by pre-tensioned stainless steel ribbons. Construction and Building Materials, v. 73, p. 740–753, 1 dez. 2014. DOI: 10.1016/j.conbuildmat.2014.09.116

THOMOGLOU, A. K.; P. JAGADESH; VOUTETAKI, M. E. Review of Out-of-Plane Strengthening Techniques of Unreinforced Masonry Walls. Fibers, v. 11, n. 9, p. 78–78, 19 set. 2023. DOI: 10.3390/fib11090078

TORRES, B. et al. Textile reinforced mortars (TRM) for repairing and retrofitting masonry walls subjected to in-plane cyclic loads. An experimental approach. Engineering Structures, v. 231, p. 111742, mar. 2021. DOI: 10.1016/j.engstruct.2020.111742

XU, W. et al. Experimental and numerical investigation on the seismic performance of masonry walls reinforced by PC panels. Journal of Building Engineering, v. 58, p. 105049–105049, 6 ago. 2022. DOI: 10.1016/j.jobe.2022.105049

YARDIM, Y.; LALAJ, O. Shear strengthening of unreinforced masonry wall with different fiber reinforced mortar jacketing. Construction and Building Materials, v. 102, p. 149–154, jan. 2016. DOI: 10.1016/j.conbuildmat.2015.10.095

Published

2026-05-15

How to Cite

BRITO, Isaac Sérgio Araújo de; LIMA, Victor Marcelo Estolano de; OLIVEIRA, Tiago Ancelmo de Carvalho Pires de; RABBANI, Emilia Rahnemay Kohlman. Strengthening of unreinforced masonry: A systematic review of mechanical performance gains and limitations of reinforcement systems. National Journal of City Management, [S. l.], v. 14, n. 91, p. e2544, 2026. DOI: 10.17271/23188472149120266364. Disponível em: https://publicacoes.amigosdanatureza.org.br/index.php/gerenciamento_de_cidades/article/view/6364. Acesso em: 17 may. 2026.