•Diagonal compression testing of 10 walls retrofitted with 3 different TRM solutions.•Basalt grid, steel textile and NSM stainless steel rebars embedded in lime mortar.•Symmetric and asymmetric TRM ...configurations are considered for retrofitting.•Two walls tested again after repair with restoration lime mortar and basalt textile.•TRM systems provide increase of ductility and strength compared with URM walls.
This paper presents an experimental study of the structural behaviour of masonry walls retrofitted with Textile Reinforced Mortar (TRM) to improve their in-plane shear strength and deformation capacity. The experimental programme consists in diagonal compression testing of ten specimens of clay brick and lime mortar masonry retrofitted with three different TRM systems: i) continuous bidirectional grids of basalt TRM, ii) discrete bands of unidirectional steel TRM and iii) continuous basalt TRM on the wall’s inner face and bed joints structural repointing with near surface mounted helical stainless steel bars on the wall’s outer face. Two of the specimens were tested two times, i.e. in the unreinforced condition and subsequently in the repaired configuration including basalt TRM retrofitting. The experimental results show that the adopted TRM solutions produce a beneficial increase of shear resistance and ductility, making them suitable for seismic retrofitting and post-earthquake repair.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
The experimental determination of the parameters that characterise the in-plane shear behaviour of masonry structures is still a challenging task. Different authors have identified the key role of ...tensile strength in the definition of the in-plane shear behaviour of masonry, but unfortunately its direct experimental characterisation is not always feasible, and masonry’s tensile strength needs to be obtained from complex testing methodologies. As a result, tensile strength needs to be assessed from testing setups such as diagonal compression testing and shear compression testing when the failure mode of masonry is featured by tensile diagonal cracking. However, different formulations are available in the scientific literature regarding the interpretation of the experimental results derived from such tests. This work provides new insights on the interpretation of in-plane shear experimental behaviour of double-leaf historical clay brick masonry walls with low strength mortar joints, both unreinforced and retrofitted with textile reinforced mortar and steel reinforced grout. The research evaluates results derived from both testing methodologies, and investigates the potential correlation between them to fully characterise the in-plane shear behaviour of masonry walls. Finally, a numerical model is used to simulate each testing configuration and study the stress state at the centre of the walls to determine the tensile strength and its correlation with the shear strength and the maximum load attained.
•Shear compression test (SCT) and diagonal compression test (DCT) on brick walls.•Proposal of an empirical correlation between SCT and DCT experimental results.•Simulation of DCT and SCT by FE macro model to evaluate stress state in the walls.•DCT is validated as a simpler test to evaluate the tensile strength of masonry.•Proposal of a coefficient α= 0.4 to compute tensile strength from DCT’s peak load.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
This paper reports an experimental programme on masonry walls composed of handmade solid clay brick and hydraulic lime mortar. Reversed cyclic shear compression tests were carried out on the walls in ...three different configurations: unreinforced, repaired and retrofitted, and just retrofitted. Damaged walls were repaired and retrofitted with Basalt Textile Reinforced Mortar (B-TRM) and tested again to investigate the recovery of strength, stiffness and the improvement in drift capacity. The repair consisted in filling the open cracks and replacing the damaged bricks by following the so-called “scuci-cuci” technique. The just retrofitted configuration consisted of externally bonded B-TRM on undamaged walls. The B-TRM system comprised continuous bidirectional grids of basalt fibre embedded in hydraulic lime mortar on both surfaces of the walls. The experimental results showed the suitability of the proposed solutions for seismic retrofit and post-earthquake repair of existing masonry buildings. The research results highlighted the capacity of the proposed repair technique to reinforce damaged walls and the effectiveness of the investigated B-TRM system in increasing the resistance, the ductility, and the energy dissipation of unreinforced clay brick masonry. In addition, the results allowed a better understanding of the behaviour of masonry walls subjected to cyclic horizontal displacement in terms of failure mechanism and displacement capacities.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
The paper presents an experimental program on the characterisation of the mechanical behaviour of perforated brick masonry (PBM) under uniaxial compression. The study is aimed to provide a better ...understanding on the compressive strength and elastic behaviour of a kind of masonry hardly dealt with in the literature. The mechanical response of the investigated masonry shows actually two complexities, linked respectively to the perforated nature of the bricks and the asymmetric cross-section of the units. The latter feature is particularly recurrent in exposed brickwork composed of perforated bricks, whenever one of the face shells has a larger thickness than the other one. For this purpose, an experimental campaign was carried out on units and PBM subjected to uniaxial compressive loading. The mechanical response of PBM is investigated to accurately determine the masonry Young’s modulus and the compressive strength. Measurements obtained with conventional sensors are compared with those derived from the Digital Image Correlation (DIC) technique. Lastly, the experimental findings in terms of compressive strength and Young’s modulus are cross-referenced with the estimations derived from empirical criteria available in Eurocode 6 and ACI 530.1–02.
•Characterisation of the compressive response of Perforated Brick Masonry (PBM).•Derivation of compressive strength and Young’s Modulus of asymmetric brick PBM.•Novel concept of co-barycentric area to calculate the compressive strength of PBM.•.DIC technique for the computation of Young’s Modulus and Poisson’s ratio of PBM•Comparison between experimental results and available empirical formulation.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Masonry arch bridges are essential elements of the road and railway networks of Europe, as they pertain to cultural heritage and play an important role in transportation. The integrity and safety of ...these centuries-old structures must be ensured. Therefore, there is great interest in understanding the behavior of masonry arch bridges and monitoring their health. Efficient methods for assessing the condition of structures, including inspections and monitoring, constitute a fundamental element of structural health monitoring (SHM) applications. Given the multitude of surveying techniques available, it becomes crucial to establish cost-effective sensor placement strategies capable of detecting structural failures. These strategies can involve identifying particularly sensitive areas, optimizing the number of sensors used, as well as refining the number and duration of monitoring setups, among other considerations. As part of the PONT3 project, which aims to develop a comprehensive and cost-effective approach to anticipate failure propagation in ageing bridges, this research focusses on developing interoperability-driven inspection and monitoring strategies to provide data that will allow anticipating the evolution of possible failure scenarios. In this regard, an extensive summary of the key characteristics of inspection and monitoring technologies, and typical system configurations in existing literature for masonry arch bridges will be provided. Then, the measurable physical parameters of interest for a specific failure propagation scenario will be identified using numerical simulations and applicable monitoring techniques for each of the physical parameters will be determined. Monitoring requirements in terms of measurement locations, accuracy, range, and temporal resolution will also be identified. The recommendations for interoperability-driven data collection to exchange and employ acquired information for the purpose of structural diagnosis will conclude the framework. The study will finally discuss a future outlook on the development of integrated SHM-oriented digital twins.
The implementation of Structural Health Monitoring (SHM) offers the prospect for sustainable and safe service‐life extension of existing bridges, a large portion of which is approaching the end of ...their nominal life. Many SHM frameworks for civil infrastructure address timely damage detection and identification. However, the scarcity of case studies on real damaged bridges hinders the generalized application of SHM in practice. In this contribution, monitoring data from a four‐day campaign on the Ponte‐Moesa bridge, a three‐span concrete box‐girder bridge, is presented as a benchmark for data‐driven damage diagnosis schemes. The monitoring data, covering accelerations from ambient and forced vibrations, contains the reference state after concluding the service life along with several gradually increasing damage states, including drilling holes and cutting reinforcement rebars and prestressed cables. The potential of damage‐sensitive features to identify damage is presented and the uncertainties, resulting from the environmental and operational conditions and sensor malfunctioning, pertaining to robust damage detection are discussed. Drawing from real bridge monitoring data, a range of prospects and open challenges of vibration‐based SHM for bridges are reviewed.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
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