Forthcoming and Online First Articles

International Journal of Masonry Research and Innovation

International Journal of Masonry Research and Innovation (IJMRI)

Forthcoming articles have been peer-reviewed and accepted for publication but are pending final changes, are not yet published and may not appear here in their final order of publication until they are assigned to issues. Therefore, the content conforms to our standards but the presentation (e.g. typesetting and proof-reading) is not necessarily up to the Inderscience standard. Additionally, titles, authors, abstracts and keywords may change before publication. Articles will not be published until the final proofs are validated by their authors.

Forthcoming articles must be purchased for the purposes of research, teaching and private study only. These articles can be cited using the expression "in press". For example: Smith, J. (in press). Article Title. Journal Title.

Articles marked with this shopping trolley icon are available for purchase - click on the icon to send an email request to purchase.

Online First articles are published online here, before they appear in a journal issue. Online First articles are fully citeable, complete with a DOI. They can be cited, read, and downloaded. Online First articles are published as Open Access (OA) articles to make the latest research available as early as possible.

Open AccessArticles marked with this Open Access icon are Online First articles. They are freely available and openly accessible to all without any restriction except the ones stated in their respective CC licenses.

Register for our alerting service, which notifies you by email when new issues are published online.

We also offer which provide timely updates of tables of contents, newly published articles and calls for papers.

International Journal of Masonry Research and Innovation (53 papers in press)

Regular Issues

  •   Free full-text access Open AccessExperimental, analytical, and numerical investigations on bond behaviour of basalt TRM systems
    ( Free Full-text Access ) CC-BY-NC-ND
    by Eloisa Fazzi, Giulia Misseri, Luisa Rovero 
    Abstract: In this study, a composite system designed for the reinforcement of masonry structures is investigated. The constituents of the composite system are a basalt-fibre mesh and a lime-based mortar matrix. Two basalt-fibre mesh textiles showing one double the reinforcement of the other due to a tighter spacing of yarns were considered. Three solutions were tested: one layer of the looser textile, one layer of the tighter and two layers of the looser one, providing the same reinforcement ratio of the tighter. The experimental campaign addressed single-lap shear tests on bricks. Also, within a fracture process zone approach, bond behaviour of the composite system, assuming a trilinear cohesive material law, is modelled in closed form, solving the system of differential equations. Further, a numerical finite-difference based solution is set up and compared to the analytical and experimental ones.
    Keywords: basalt fibres; lime mortar; FRCM; TRM; cohesive material law; CML; finite-difference; single-lap shear test; bond test; direct shear test.
    DOI: 10.1504/IJMRI.2022.10051005
     
  • Analysis of a nonlinear model arising in chemical aggression of marble   Order a copy of this article
    by Giuseppe Alì, Isabella Torcicollo, Carmelo Scuro 
    Abstract: We present a simple model describing the chemical aggression undergone by calcium carbonate rocks in presence of acid atmosphere. A large literature is available on the deterioration processes of building stones, in particular in connection with problems concerning historical buildings in the field of cultural heritage. It is well known that the greatest aggression is caused by sulphur dioxide and nitrate. In this paper we consider the corrosion caused by sulphur dioxide, which, reacting with calcium carbonate, produces gypsum. The model proposed is obtained by considering both the diffusive and convective effects of propagation and assuming that the porous medium is saturated with a compressible fluid having an assigned polytropic constitutive equation for the pressure. The qualitative behaviour of the one-dimensional solutions in the fast reaction limit is performed.
    Keywords: porous media; chemical reactions; Stefan problem; fast reaction limit.
    DOI: 10.1504/IJMRI.2021.10043511
     
  • Bond of CFRP/GFRP strips in the strengthening of walls   Order a copy of this article
    by Roberto Capozucca, Erica Magagnini, Giuseppe Pace 
    Abstract: In recent years, the research about strengthening techniques designed to prevent collapse and severe damages under seismic actions in masonry structures using composite materials increased considerably. Although the experimental and theoretical results are numerous, the central aspect of delamination of the strengthening with external bonded (EB) FRP strips on masonry surface need a deep analysis yet. Experimental results may assess the availability of technique for rehabilitation of damaged masonry buildings subjected to seismic action. This paper deals with the experimental results on the bond of carbon-FRP and glass-FRP strips considering pull-out tests and theoretical model useful to define the shear-slip laws. Further, the behaviour of brickwork wall models strengthened with CFRP/GFRP strips subjected to combined compression shear loading is analysed. The results are discussed, focusing the attention on the comparison of fracture energy developed during the different tests.
    Keywords: brickwork wall; external bonded strengthening; G/CFRP; pull-push tests; cyclic shear tests; delamination.
    DOI: 10.1504/IJMRI.2022.10046128
     
  • Literature review on the mechanical properties estimation of historical masonry buildings: application of an evaluation method for the Algerian case   Order a copy of this article
    by Hatem Seboui, Allaeddine Athmani, Antonio Formisano 
    Abstract: Nowadays, studying the behaviour of the old masonry structures is a challenging scope, wherein the knowledge of their material’s mechanical properties is a preliminary input for their modelling purposes. Several methods can estimate these properties. Unfortunately, for the Algerian case, on the one hand, often these estimation methods could not be carried out, which led to the absence of scientific regulations and databases of the historical materials. On the other hand, the Algerian historical buildings stock needs urgent intervention and analysis for its conservation and preservation due to the deterioration state. In this context, the current research paper attempts to review the methods available in the literature used worldwide to evaluate the material properties of old masonry buildings through a deep comparison of scientific sources aiming at finding a possible and reliable way to determine the mechanical features of historical masonry constructions in Algeria.
    Keywords: historical masonry materials; mechanical properties; ultrasonic pulse velocity test; direct approach; indirect approach.
    DOI: 10.1504/IJMRI.2022.10046050
     
  • Fully analytical model for the analysis of externally bonded composites applied to brittle supports: sensitivity analysis   Order a copy of this article
    by Elisa Bertolesi, Gabriele Milani, Ernesto Grande, Roberto Capozucca 
    Abstract: Several analytical models have been proposed reducing the debonding mechanism to a bond loss event occurring in inelastic interfaces, whose mechanical properties need to be adjusted based on available experimental data. The analytical model developed by the authors and briefly recalled in this work, considers an elastic FRP bonded to brittle supports by means of inelastic interfaces. In detail, the inelastic interface is described by an initial linear elastic phase (phase 1) and a decreasing exponential softening law (phase 2). This article demonstrates the reliability of the proposed model to study the adhesion performance and failure modes of FRPs applied on different brittle supports. The model is widely benchmarked using the results obtained from two laboratory investigations on flat concrete and masonry prisms reinforced with FRP composite materials and an extensive sensitivity analysis performed by varying different parameters, namely: bond length, interfacial bonding law and FRP mechanical properties. Each parameter is discussed with respect to: 1) the obtained global force-slip curves; 2) force increase; 3) post-peak response.
    Keywords: debonding mechanisms; FRP composites; closed form solution; concrete; masonry.
    DOI: 10.1504/IJMRI.2022.10046112
     
  • Influence of masonry infill configuration on seismic response in RC frame structures over soft and medium soil conditions   Order a copy of this article
    by Ronak Motiani, Sandip Vasanwala, Tejaskumar Thaker 
    Abstract: The geological faults, soil amplification, mass, and stiffness of the building governs its seismic performance. The seismic vulnerability of a buildings is assessed in this study considering all the above mentioned parameters. The extended finite fault modelling is used to generate ground motions at the engineering bedrock level. Furthermore, the field tests are carried out using multichannel analysis of surface wave (MASW) equipment on soft and medium soil conditions and results are used for the ground response analysis to obtain surface-level ground motions. These motions are used for nonlinear time history analysis of the reinforced concrete buildings with different masonry infill orientations. Finally, the outcome of the analysis is to derive the fragility curves using inter-storey drift (ISD) as damage measure (DM) and peak ground velocity (PGV) as an intensity measure (IM).
    Keywords: URM infill; reinforced concrete; soil amplification; synthetic ground motions; fragility curves.
    DOI: 10.1504/IJMRI.2022.10046740
     
  • Review of thermal performance, hygrothermal behavior, and carbon sequestration in hemp concrete in order to make it an energy-efficient and eco-friendly material   Order a copy of this article
    by Neha Chandrakar 
    Abstract: Since a few decades ago, the construction industry has had pressure to find new building techniques and materials to meet energy-efficiency targets. It might be time to be aware of energy-efficient materials and methods to reduce pollution due to construction. Many new and advanced building techniques and materials are available in the market. Most of these techniques and materials involve plastic, petro-chemical-based substances, and other toxic substances that pollute the environment and planet when disposed of. There are so many low-energy buildings constructed, but they have been used more in their material. This study concerns the life cycle assessment of an environmentally friendly material for building hemp concrete. This paper analyses the thermal performance, relation with CO2 emission of hemp concrete and understand variation in thermal performance with water content, temperature and composition ratio, which set it apart from other traditional building material. Hemp concrete is an eco-friendly and energy-efficient building material due to its various natural and unique properties.
    Keywords: thermal performance; breathability; hygroscopicity; low carbon emission; energy-efficient.
    DOI: 10.1504/IJMRI.2022.10046884
     
  • Valuation on the strength properties of gypsum based PCM cement mortar   Order a copy of this article
    by D. Gift Pon Lazarus, Sunita Bansal 
    Abstract: The construction industry moving towards developing sustainable and smart building materials in recent decades rapidly due to the population range and the rising living comfort standards. In this study the compressive strength gypsum based PCM cement mortar evaluated in building construction envelope materials. The inert mortar composition of phase change materials (PCMs) allows the phase transition from solid to liquid and liquid to solid by its natural characteristics. In this study, gypsum powder (G) is utilised to encapsulate with paraffin wax to make gypsum with PCM aggregates also it is replacement with fine aggregates used in cement mortar. In order to use PPC cement, quartz sand, gypsum with PCM aggregates and water mixture was used to produce gypsum based PCM cement mortar. The variation in strength properties with different mix proportion of gypsum with PCM aggregates respect to quartz sand was investigated to achieve the optimum required strength properties of the mortar.
    Keywords: phase change materials; PCMs; gypsum; buildings materials; sustainable building materials; smart building materials.
    DOI: 10.1504/IJMRI.2022.10047066
     
  • Local effects of bonding on the strength of drystone masonry in Iron-age brochs   Order a copy of this article
    by Dimitris Theodossopoulos, Jenny Gilbertson, Wei He, Katherine Primavesi, Bowen Qiu, Franziska Reutter 
    Abstract: Collapses in drystone prehistoric Scottish broch towers probably started from localised failures at the supports of roofs or decks, settlements, ill-conceived modifications or gradual decay producing long-term accumulation of debris. Another source of instability is their precarious state during excavations. Some of these effects have been simulated as excessive lateral thrust or settlement and are studied here through experimental analysis on wallettes in 1/15 scale, expanding on earlier insight from complete broch models tested to settlement. Wallettes in typical bonds were tested following a parametric study on the effect of thickness, bond and architectural features (openings, corbelled chambers, uneven supports). Failure patterns at overturning and settlement were established, triggered at a minimum lateral displacement of one-fifth of the wall thickness. The walls could resist a lateral earth pressure representing debris accumulation at least 5 times their active earth pressure and resistance to settlement was by arch formation at the base.
    Keywords: brochs; drystone masonry; settlement; lateral earth pressure.
    DOI: 10.1504/IJMRI.2022.10047690
     
  • Shrinkage and creep behaviour of thin layered mortared masonry   Order a copy of this article
    by Julian Thamboo, Jiffry Mohamed 
    Abstract: Thin layer mortared masonry (TLMM) system is one of the alternatives to the traditional masonries to accelerate the wall construction. The creep and shrinkage deformation of the masonry can be minimised by adopting TLMM construction, where thin layer (0.5 mm to 3 mm) and stronger mortars (>10 MPa) can be used. Subsequently, a comprehensive experimental campaign was implemented to investigate the shrinkage and creep shortening characteristics of TLMM. The influence of: 1) masonry type (clay and concrete); 2) prestress levels (10%, 20 and 30%); 3) age of loading (3 and 7 days) on the TLMM shrinkage and creep characteristics were examined over 300 days. The creep coefficients obtained for the clay and concrete TLMM prisms range from 0.37-1.10 and 0.42-1.38, respectively. Using the experimental data, empirical time dependent formulations to determine the evolutions of shrinkage and creep characteristics of TLMM were established. Finally, shrinkage and creep parameters obtained in the study are compared with the data given in literature.
    Keywords: thin layer mortared masonry; TLMM; creep; shrinkage compressive strength; mortar; rheological models.
    DOI: 10.1504/IJMRI.2022.10047777
     
  • Experimental assessment of diagonal shear parameters of dry stacked block masonry built with self-interlocking compressed earth blocks   Order a copy of this article
    by Akhtar Gul, Inayat Ullah Khan, Bashir Alam, Khan Shahzada 
    Abstract: The surface characteristics of dry stack block masonry, built with interlocking blocks, control the overall performance of a structure. In this research work, the shear parameters of dry stack block masonry (DSBM) have been evaluated experimentally by testing DSBM walls through diagonal tension testing protocols. The DSBM walls were tested under the diagonal compression loading with and without edge load. The results have been evaluated by using available research models. Coefficient of friction, cohesion, diagonal tensile strength, shear strength, and shear modulus have been found from the experimental tests. This study shows that the shear parameters of DSBM are greatly influenced by axial compression. In the presence of axial compression load, the values of shear parameters of DSBM are closely matched with the values of regular mortared masonries.
    Keywords: diagonal tension test; DTT; dry stack block masonry; DSBM; cohesion; friction coefficient; edge load; shear parameters; Elastic modulus; shear modulus; state of stress; diagonal compression loading.
    DOI: 10.1504/IJMRI.2022.10048224
     
  • Study on the influence of structural interventions to monuments based on in-situ ambient vibration measurements at Matsopoulos Mill, Trikala, Greece   Order a copy of this article
    by Thomas N. Salonikios, Konstantinos E. Morfidis, Nikolaos P. Theodoulidis 
    Abstract: In present paper, results are presented from the postprocessing of ambient vibration measurements at a mill building. The mechanical properties of the structural elements were estimated through these records. It was found that the eigen-properties of the final structure are not significantly altered due to the simultaneous increment of the mass and the stiffness of the building. The in situ measurements document that both the added and the existing structural elements cooperate in the carriage of the applied loads. It was additionally found that, as a result of the operation of the mechanical equipment, the structural system of building is significantly vibrated. Therefore, it is proposed that the use and operation of this equipment for display purposes should be limited. Finally, the need for a re-examination of the structure in the near future is also proposed, as it is necessary for the certification of the sustainability of the interventions.
    Keywords: ambient vibrations; mass addition; stiffness addition; eigen-properties; influence of interventions; monument; mill.
    DOI: 10.1504/IJMRI.2022.10048710
     
  • Experimental studies on blast performance of unreinforced masonry walls of clay bricks and concrete blocks: a state-of-the-art review   Order a copy of this article
    by S.M. Anas, Mehtab Alam, Mohammad Umair 
    Abstract: In this paper, available experimental studies on clay-brick and concrete block URM walls subjected to blast loading are briefly reviewed and summarised. Studies conducted to improve the blast resistance of the walls using G-FRP strips, G-FRP rods, and Polyurea coating, and their effect on maximum deflection, damage, and cracking have also been recapitulated. Detail summary for strengthening and retrofitting of the walls is presented in tabular form. It is observed that the effect of brick and mortar strength on maximum mid-span deflection and damage resistance of wall is insignificant under higher reflected blast pressure (> 2MPa). However, Young’s modulus of masonry is found to be a predominant parameter in improving the deflection response of the wall. The mode of failure of a wall is governed by the magnitude of peak overpressure, blast duration, and boundary conditions. Scope for further studies on a hybrid form of the walls is recommended.
    Keywords: blast loading; blast parameters; clay bricks; CL; concrete blocks; cracking; damage; failure modes; polyurea coating; glass fiber reinforced polymer; GFRP; unreinforced masonry; URM; walls.
    DOI: 10.1504/IJMRI.2022.10049719
     
  • Behaviour of C-FRP laminate strengthened masonry and unreinforced masonry compound walls under blast loading, Afghanistan scenario   Order a copy of this article
    by Emal Ahmadi, Mehtab Alam, S.M. Anas 
    Abstract: Afghanistan being the most suffered nation by wars, terrorism and counter-terrorism, its common people are sick of subsequent attacks and counter-attacks by warlords. Even places of worship and worshippers are not spared from these attacks. Compound walls enclosing such religious structures are found targeted by explosive blasts for the last many years. In this study, blast performance of free-standing compound URM walls commonly used in Afghanistan of one brick thickness and one-half brick thickness, made of 220 mm x 110 mm x 70 mm red clay bricks, is investigated using the ABAQUS/Explicit code by doing nonlinear analysis. The walls have also been retrofitted with the laminate of high-strength C-FRP on the explosion face only and on both faces. Macro-modelling strategy is chosen to optimise the computational time. Comparable blast performance of the strengthened walls exhibits that laminate on both the faces rules out the requirement of the higher thickness of the masonry wall.
    Keywords: blast loading; C-FRP laminate; CDP model; damage; masonry walls; numerical simulations; Afghanistan.
    DOI: 10.1504/IJMRI.2022.10049968
     
  • Physical, mechanical, and bonding properties comparison of lightweight foam concrete brick with burnt clay brick used in masonry   Order a copy of this article
    by Manan Hashim, Manzoor Tantray 
    Abstract: Even as technology advances, brick masonry remains the oldest form of construction. Over the last decade, lightweight bricks have gained popularity in building construction. The study was undertaken to evaluate the engineering performance of high-strength lightweight bricks. The physical properties, i.e., density, water absorption, and initial rate of absorption, mechanical properties, i.e., compressive strengths of brick and their prisms and modulus of elasticity, and bonding strength, i.e., shear strength and flexural tensile strength. Additionally, these properties were compared with the burnt clay brick. The bulk density of lightweight brick was found to be approximately 46% lower than burnt clay brick. Lightweight brick and their masonry prisms had compressive strengths of 9.98% and 15.63% greater than burnt clay brick and masonry prisms, respectively. The weak flexural and shear bond strength of lightweight brick can be improved by increasing contact surface, surface roughness, and providing frog.
    Keywords: lightweight foam concrete brick; burnt clay brick; physical properties; mechanical properties; bond strength properties.
    DOI: 10.1504/IJMRI.2022.10050256
     
  • Numerical assessment of movement joint spacing in masonry veneer walls with high-strength steel bed joint reinforcement   Order a copy of this article
    by Rutger Vrijdaghs, Yassin Zabbar, Gerhard Vitt, Els Verstrynge 
    Abstract: The addition of bed joint reinforcement (BJR) to masonry improves the structural behaviour by limiting crack widths and increasing the post-cracking capacity. However, the design of BJR according to Eurocode 6 does not take into account the material properties, and may lead to uneconomical designs. In this paper, the structural behaviour of reinforced masonry with a truss-type and high-strength wire-type BJR is investigated under thermal contraction loading using macromechanical finite element modelling to compare crack widths in order to assess the design approach of Eurocode 6. Varying wall lengths (12 m, 18 m and 24 m), reinforcements (normal and high strength BJR) and boundary conditions (fixed and sliding) are taken into account. The results show that BJR significantly limits the maximum crack widths by increasing the number of cracks. The simulations show that increased spacing between thermal expansion joints can be allowed beyond the current recommendations of Eurocode 6, optimising the design.
    Keywords: macromechanical modelling; thermal contraction; bed joint reinforcement; BJR; reinforced masonry; crack modelling.
    DOI: 10.1504/IJMRI.2022.10050981
     
  • Role of UHPC in-lieu of ordinary cement-sand plaster on the performance enhancement of masonry wall under close-range blast loading: a finite element investigation   Order a copy of this article
    by S.M. Anas, Mehtab Alam, Mohammad Umair 
    Abstract: In this study, a URM wall along with bracing lateral walls on the same side at each end is micro-modelled in ABAQUS software with an explicit module and investigation has been carried out for its blast performance under the 7.49 kg-TNT load at scaled distance 1.83 m/kg1/3. The concrete damage plasticity model including the strain-rate effects is used to model the nonlinear behaviour of bricks and mortar-joints. The finite-element model is calibrated and validated by comparison with the experimental results of Badshah et al. (2021). To prevent the damage catastrophe of the wall, protective coatings of: 1) ultra-high-performance concrete (UHPC); 2) ultra-high-performance fibre-reinforced concrete (UHPFRC), of 15 mm thickness have been considered as strengthening materials. Damage to the UHPFRC coated braced masonry wall is found to be not only much small in magnitude but also restrained over much less area as compared to the UHPC coated wall under close-range blast loading.
    Keywords: blast loading; masonry walls; micro-modelling; bricks; mortar joints; concrete coatings; damage; numerical simulation; stresses.
    DOI: 10.1504/IJMRI.2022.10051229
     
  • Strengthening of unreinforced braced masonry wall with (1) CFRP laminate and (2) mild-steel strips: innovative techniques, against close-range explosion   Order a copy of this article
    by S.M. Anas, Mehtab Alam, Mohammad Umair, Manal Hadi Ghaffoori Kanaan 
    Abstract: In this paper, nonlinear explicit dynamic analyses under the TNT equivalent charge weights of 4.34 and 7.49 kg at scaled distances 2.19 and 1.83 m/kg1/3, respectively, are conducted on unreinforced braced clay brick masonry wall using the ABAQUS/Explicit code considering Concrete Damage Plasticity model with loading-rate effects. Computed damage patterns are found closely matching with the experimental results of Badshah et al. (2021). Efforts are made to strengthen the wall following: 1) C-FRP wrapping; 2) steel-strip mesh with angle sections at the edges of the wall. The load carried and its mechanism by unreinforced and strengthened walls are highlighted. Damage to the wall strengthened with 2 mm thick CFRP wrapping on both the faces is found comparable with the wall strengthened with strips and angles of thickness 5 mm under blast loading. From the ease of application point of view, strengthening the wall with wrapping is better than with the steel strip-angle technique.
    Keywords: bricks; C-FRP wrapping; damage; explosions; masonry; micro-modeling; nonlinear analysis; steel jacketing; structural performance; stresses.
    DOI: 10.1504/IJMRI.2022.10051230
     
  • Dynamic behaviour of free-standing unreinforced masonry and composite walls under close-range blast loadings: a finite element investigation   Order a copy of this article
    by S.M. Anas, Mehtab Alam 
    Abstract: In this paper, the finite element simulations of compound unreinforced brick masonry wall, 6,000 mm x 2,500 mm x 350 mm, subjected to experimental blast pressures are performed using ABAQUS computer code equipped with concrete damage plasticity model. A macro-modelling technique is adopted to optimise the computational time. Dynamic responses including maximum displacement, damage dissipation energy, and crack/damage patterns have been evaluated for the scaled distances of 2.28 and 1.81 m/kg1/3. With the objective to improve the blast performance of the wall, a 230 mm thick reinforced concrete (RC) wall with a 70 mm wide cavity is considered in the study. To dissipate the explosion energy, bricks on edge, and sand are also taken as softcore materials in the cavity of the wall. The cavity is interrupted by the cross RC elements at an interval of 1.10 m. Analyses results have been discussed and a novel design of the blast-resistant free-standing wall is recommended.
    Keywords: explosions; masonry; composite walls; blast pressure; cavity; bricks; sand; damage; displacement.
    DOI: 10.1504/IJMRI.2022.10051379
     
  • Influence of wire mesh, and CFRP strengthening on blast performance of brick masonry wall: a numerical study under close-range explosion   Order a copy of this article
    by Mohd Shariq, Mehtab Alam, S.M. Anas, Asif Hussain, Nazrul Islam 
    Abstract: A common structural member in the buildings used for both commercial and residential formats is load-bearing brick masonry walls. In this study, a finite-element model of unreinforced brick-masonry wall, 1,600 mm x 2,100 mm x 240 mm, is developed, analysed, and validated with the available test results using the ABAQUS/Explicit-v.6.15 code under 5 kg-TNT load at scaled distance 0.58 m/kg1/3. To improve the wall response, it has been strengthened with: 1) wire mesh of different thicknesses 2.50 mm, 3.50 mm, and 4.50 mm on the rear face only and on both the faces of the wall; 2) CFRP wrapping with 0.50 mm and 0.60 mm thick on the rear face only and 0.30 mm thick on both the faces of the wall. Equivalent thickness of the wrapping to the steel wire-mesh from displacement and damage point of view is evaluated. CFRP-strengthened walls displayed better performance than walls with wire-mesh with regards to damage and displacement.
    Keywords: brick masonry; blast loading; CFRP; damage; load-bearing structures; micro-modelling; strain-rate effects; wire mesh.
    DOI: 10.1504/IJMRI.2022.10051479
     
  • Blast response prediction of unreinforced masonry wall with varying mortar strength and axial load   Order a copy of this article
    by Mohd Shariq, Mehtab Alam, Asif Hussain, Nazrul Islam, S.M. Anas 
    Abstract: A detailed micro-model of clay brick unreinforced masonry wall is developed in this study with dimensions 5,000 mm x 2,800 mm x 230 mm braced with two columns. The response of the wall carrying different values of axial compression is investigated under close-in blast loading. Three walls with identical brick units but of different mortar strength namely; 2.50 MPa, 5 MPa, and 7.50 MPa, have been modelled. Each model is subjected to axial compression of 9 kN/m, 30 kN/m, and 51k N/m corresponding to the axial load on third story wall, second story wall and first story wall of a 3-story masonry building respectively. The investigations have been done using a high-fidelity program, ABAQUS/CAE with concrete-damage-plasticity under the 10kg-TNT blast load at scaled distance 0.464 m/kg 1/3. The study recommends the use of mortar of strength 5 MPa and 7.50 MPa under moderate and higher axial loads, respectively, for minimum displacement response of the brick masonry wall subjected to the blast loading.
    Keywords: bricks; masonry walls; blast loading; parametric study; mortar strength; axial load; damage.
    DOI: 10.1504/IJMRI.2022.10051480
     
  • Behaviour and damage assessment of monolithic and non-monolithic braced masonry walls subjected to blast loadings using a detailed micro-modelling approach   Order a copy of this article
    by S.M. Anas, Mehtab Alam, Mohammad Umair 
    Abstract: This research work investigates the out-of-plane blast response of the URM walls, made of clay bricks, braced with: 1) monolithic; 2) non-monolithic transverse walls, using a three-dimensional detailed micro-modelling approach. For this purpose, the finite elements method implemented ABAQUS/Explicit commercial software is used. In addition to the braced walls, one free-standing URM wall (without transverse walls) is considered and analysed in the study. The concrete damage plasticity model including the strain-rate effects is used to model the masonry behaviour to blast loadings. Computed damage patterns of the wall braced with monolithic transverse walls are compared with the experimental ones from the open literature and a good agreement is found between them. It has been found that the non-monolithic joints between the exposed wall and transverse bracing walls reflect a higher degree of damage to the bracing walls, which is governed by the response of the exposed wall.
    Keywords: masonry walls; blast loading; micro-modelling; numerical simulations; non-monolithic connections; CDP model; damage; energy dissipation.
    DOI: 10.1504/IJMRI.2022.10051512
     
  • Towards a better understanding of 3D heat flow in masonry walls   Order a copy of this article
    by Joelle Al Fakhoury, Emilio Sassine, Yassine Cherif, Joseph Dgheim, Emmanuel Antczak, Thierry Chartier 
    Abstract: Hollow block masonry is a widely used building technology in many countries. These blocks are handcrafted and have unknown thermal properties; therefore, their overall thermo-physical performance is also poorly studied scientifically in single and double wall configurations. In this work, experimental measurements and numerical simulations are performed for a better understanding of heat transfer in masonry walls. The thermal properties of the materials constituting the wall were first determined separately, then a thermal characterisation on a hollow masonry block sample wall (0.1 m x 1 m x 1 m) was realised by imposing different thermal conditions on one side of the wall using a control heating box with an adjustable interior temperature, the other side remaining exposed to the ambient condition of the laboratory. The experimental results were first compared to a numerical 3D model for validation; then the effects of the geometric and thermal properties of the wall components were analysed in order to recommend some qualitative and quantitative improvements. The results showed that the masonry blocks thermal properties have the major impact on the masonry block thermal performance allowing to reach around 178% of thermal improvement.
    Keywords: masonry wall; hollow block; heat flow; temperature; boundary condition scenarios; steady state; harmonic regime; stochastic regime; 3D model.
    DOI: 10.1504/IJMRI.2022.10052155
     
  • The physical, mechanical and thermal properties of lightweight cement mortar containing grated expanded polystyrene waste   Order a copy of this article
    by Aqil M.K. Almusawi, Rana Shabbar, Tamara Adnan Qasim 
    Abstract: The reuse of expanded polystyrene waste (EPSw) in cement mortar is a solution to improve the insulation, comfortability, sustainability and reduce energy consumption in buildings. EPSw cement mortar is a new lightweight building material that reveals great physical-mechanical properties that are suitable for the construction field. Five groups of cement mortars containing grated EPSw (20%, 30%, 40%, 50%, and 60% by volume) were produced in addition to the reference mix (0% EPSw). The physical, mechanical properties and thermal conductivity of the lightweight cement mortar (LWCM) were determined. By using a superplasticiser admixture and grated EPSw, the non-homogeneous distribution of the components was controlled. The results indicated that the highest reduction in the thermal conductivity was 71% for the specimens containing 60% EPSw.
    Keywords: lightweight cement mortar; LWCM; thermal conductivity; physical and mechanical properties; expanded polystyrene waste; EPSw.
    DOI: 10.1504/IJMRI.2022.10052913
     
  • Numerical modelling of masonry-concrete composite wall response to blast loads   Order a copy of this article
    by S.M. Anas, Mehtab Alam, Mohd Shariq, Mohammad Umair, Farman Saifi, Manal Hadi Ghaffoori Kanaan 
    Abstract: Masonry walls are commonly used in both residential and office buildings as either load-carrying structural components or partition walls. Failure of a load-carrying masonry wall to explosion loading could result in the collapse of the structure. In this study, detailed finite-element model of clay brick masonry walls, 6,000 x 3,040 x 350 mm3, carrying axial compression with and without reinforced concrete core is developed in ABAQUS/Explicit software considering strain-rate effects, and simulations are performed under blast loadings. Altogether, two models are developed: the first model is consisting of a masonry wall of one-half brick thickness made with English-bond arrangement; the second model is consisting of two wythes of brick walls, 110 mm thick each, sandwiching 130 mm thick concrete core wall with grade M20 and M30 having nominal single curtain steel-reinforcement. Results reveal that the concrete core absorbs most of the explosion energy, and therefore the masonry-concrete composite wall displays excellent blast performance.
    Keywords: axial compression; blast loading; concrete strength; composite walls; brick masonry; micro-modelling; numerical simulations; damage dissipation energy; DDE; stresses.
    DOI: 10.1504/IJMRI.2023.10053134
     
  • A coupled SPH-FEM analysis of explosion-induced blast wave pressure on thin-walled cylindrical steel liquid storage tank and corresponding structural response   Order a copy of this article
    by Farman Saifi, Mohd Haris, Rafat Tahzeeb, Mohd Shariq, Mehtab Alam, S.M. Anas 
    Abstract: Thin-walled cylindrical shell storage tanks are pressure vessels having diameter to wall thickness ratio greater than 20. Such structures are commonly used in oil, gas, and petrochemical industries and therefore are vulnerable to fire and explosions. In this research work, a numerical model of a simply supported thin-walled horizontal cylindrical water storage tank is developed in ABAQUS/Explicit software and its investigation has been carried out to study the influence of water under close-range explosive loading generated from 50 kg-TNT charge at 0.50 m stand-off distance. Explosion simulations are performed using the Conventional Weapons Effects Program (ConWEP 2.0) code developed by the US Army based on the equations proposed by Kingery and Bulmash. Water is modelled using the Jones-Wilkins-Lee (JWL) equation-of-state (EOS) considering smoothed-particle hydrodynamics (SPHs) approach. Results showed that the water helped to reduce the deformation and damage to the storage tank under blast loading and therefore the blast resistance of the tank was improved.
    Keywords: blast wave; ConWEP; damage; numerical simulations; finite element modelling; FEM; SPH method; storage tanks; thin-walled structures; water effects.
    DOI: 10.1504/IJMRI.2023.10053444
     
  • A proposal for the numerical modelling of monotonic and cyclic behaviour of masonry infilled reinforced concrete frames   Order a copy of this article
    by Matteo Bagnoli, Ernesto Grande, Gabriele Milani 
    Abstract: This article is aimed at proposing a numerical model for the study of the monotonous and cyclic behaviour of reinforced concrete frames equipped with masonry infills. In fact, the main purpose of this study concerns to derive a reliable model that is able to predict the monotonic and cyclic response of reinforced concrete infilled masonry frames. To this end, after a critical analysis of the available literature, the authors combine two models, one for the monotone response and the other for the cyclic one, showing their reliability with reference to six different experimental cases. The final step considered in this article is to propose an experimental procedure to minimise the error between the numerical analysis and the results of the six experimental literature tests examined, in order to provide a family of 16 new variables that substantially improve the starting models selected.
    Keywords: infilled RC frames; non-structural elements; earthquake damages; macro-models; seismic-behaviour.
    DOI: 10.1504/IJMRI.2023.10053675
     

Special Issue on: ArCo2020 New Approaches in Diagnostic and Safety Evaluation of Cultural Heritage

  •   Free full-text access Open AccessExperimental investigations on glass fibre reinforced composites with gypsum-earth matrix to strengthen the earth walls of the Noh-Gonbad Mosque in Balkh, Afghanistan
    ( Free Full-text Access ) CC-BY-NC-ND
    by Arash Boostani, Giulia Misseri, Luisa Rovero, Ugo Tonietti 
    Abstract: The Noh Gonbad mosque is an almost unknown masterpiece dated back to the 8th century, located near Balkh, North Afghanistan. The archaeological remains show different buildings techniques such as rammed earth (for portions perimeter walls), adobe masonry (for walls, niches and abutment of the arcades) and brick masonry with earth or gypsum mortar (for domes, arch and columns). The state of ruin required targeted intervention strategies for perimeter walls. The presence of collapse debris, and the possibility of their removal, would though increase, for the masonry portions, the vulnerability against overturning connected to the seismic hazard at the site. The reported experimental campaign focus on the identification of a fibre reinforced composite system aimed at jacketing perimeter walls. Tests address different matrix compositions compatible with the substrate, i.e., based on earth and gypsum. Results enable to highlight the effect that the composition has on the mechanical response.
    Keywords: earth material; gypsum; glass fibre reinforced composites; mechanical tests; abbassid period mosque; Balkh; Afghanistan.
    DOI: 10.1504/IJMRI.2022.10046885
     
  • An integrated experimental and numerical approach for preventive Cultural Heritage conservation. The San Marco Museum case study.   Order a copy of this article
    by Margherita Vicario, Carla Balocco 
    Abstract: Microclimate knowledge inside historic buildings is a prerequisite for their preventive conservation and protection. In this research a methodological approach, based on the integration between experimental measurement and numerical simulation by means of CFD environmental control techniques, is provided. This method is aimed at identifying criticalities and risk conditions for the cultural heritage preventive conservation. The San Marco Museum in Florence is the case study. Results show that the proposed method can be a useful tool for guidelines for possible effective interventions, as well as basic rules of correct behaviour.
    Keywords: microclimate monitoring; simulation; CFD; cultural heritage; preventive conservation; historical building.
    DOI: 10.1504/IJMRI.2021.10042914
     
  • Methodological approach to the restoration of historical buildings based on microclimatic monitoring: the case of 'La Specola' Museum in Florence   Order a copy of this article
    by F. Sciurpi, C. Carletti 
    Abstract: In this paper, a methodology meant to evaluate the building-plant system of historical museum buildings is presented: in this methodology, thermophysical characteristics of the envelope and technical features of the HVAC and lighting devices are collected, microclimatic parameters are monitored and assessed, retrofitting strategies are defined and evaluated. The methodology is applied to 'La Specola' Museum in Florence, where microclimatic parameters have been monitored continuously for one year and conservation indicators have been defined and assessed. 'La Specola' is one of the oldest museums of Florence and contains zoological collection and anatomical waxes. In the paper, the results of the different retrofitting strategies, such as wall and roof insulation, window and skylight improvements, as well as the adding of shading devices, are presented and discussed for selected representative rooms.
    Keywords: museums; historical buildings; preventive conservation; evaluation methodology; microclimatic monitoring; energy modelling; calibration; retrofitting strategies.
    DOI: 10.1504/IJMRI.2022.10044043
     
  • Protection of art works to blast hazards: the Fountain of Neptune in Florence   Order a copy of this article
    by Marco Domaneschi, Marco Tanganelli, Stefania Viti, Gian Paolo Cimellaro 
    Abstract: Art works have a fundamental role in the cultural and economic status of communities. Their protection, therefore, is a fundamental goal. For the most part, artefacts are conserved in museums, which oversee their maintenance and exposure. Despite such protection, however, acts of vandalism can occur, threatening the integrity of the art works. Art works with an outdoor location are at increased risk of vandalism since they cannot be highly guarded. In this work, the protection of art works to blast hazards was checked for the Fountain of Neptune located in the 'Piazza della Signoria' in Florence. The dynamic response of the statue of Neptune to a blast was checked by performing a finite element (FE) analysis and by considering a simplified equivalent load. Special attention was paid to the limit capacity of the case study and the assumed restraint at the sculpture base.
    Keywords: Ammannati’s sculptures; artifacts; dynamic analysis; FE models; sculpture; blast hazard; dynamic response of sculptures; fountain of Neptune.
    DOI: 10.1504/IJMRI.2022.10045192
     
  • Seismic assessment of historical buildings through multilevel approach: the complex of the 'Galleria dell'Accademia di Firenze'   Order a copy of this article
    by Mario De Stefano, Maria Teresa Cristofaro 
    Abstract: The historic centre of Firenze contains, in a relatively small area, works of art housed in buildings that are themselves considered of high artistic value. The earthquake of 18th May 1895, caused extensive but not serious damage to many historic buildings and museums in the city. The present work describes a comprehensive analysis of the seismic vulnerability and risk of the complex of the 'Galleria dell'Accademia di Firenze', where several art works are exhibited, such as the Michelangelos David. These assessments were preceded by a diagnostic campaign in order to reach a Level of Knowledge and therefore an exhaustive confidence factor. In this work, all the three levels of evaluation provided by the Guide-Lines issued by the MiBACT to evaluate and reduce seismic risk of cultural heritage have been developed, following a rigorous knowledge path that allowed to reach an exhaustive assessment of the seismic performance of the complex.
    Keywords: cultural heritage; mechanical characterisation of masonry; evaluation levels; seismic response of monumental buildings.

  • The baths complex of Villa San Marco at Stabia. Investigations in a risk-assessment perspective   Order a copy of this article
    by Michele Coppola, Jacopo G. Vitale, Giulia Poli 
    Abstract: The architectural remains of Villa San Marco show a wide repertoire of degenerative situations, with multiple levels of criticality and complexity, typical of many archaeological areas. The damage caused by the ancient eruptions of the Vesuvius have been overlapped by several degradation processes, activated by Bourbon excavations, ineffective previous restorations and abandonment conditions. Speed and intensity of degenerative processes are connected to the vulnerability of the architectural remains. The aim of this research is to define a multi-scale-reading approach that allows the systematic understanding of the damage dynamics and the vulnerability of the architectural artefacts. The investigation was conducted on the remains of the thermal baths, currently closed to the public, chosen as case study. In addition to the digital documentation, a survey was carried out on the main degenerative phenomena, with attention to the loss of material and the structural stability assessment. For some phenomena, a risk analysis procedure has been proposed.
    Keywords: Stabia; risk assessment; archaeological preservation; damage dynamics; Villa San Marco; Roman painted plaster; safety in archaeological sites; structural assessment; thermal baths; multiscale-reading.
    DOI: 10.1504/IJMRI.2022.10048593
     
  • How structural engineering can help archaeology?   Order a copy of this article
    by Mauro Sassu 
    Abstract: In the present paper the 'Three R' strategy for archaeological consolidation is described, referring to some well-known historical examples and then to some significant cases on UNESCO sites. The problem of conserving the constructive information in the ancient structures along centuries is here summarised, together with examples of recurrent structural problems that affect those constructions. Three case studies of sites are explained: two located in Arabic Peninsula (Dhofar district, Sumhuram - Al Balid), one in Jordan (Petra district Shawbak). The replacement of collapsing walls (with or without mortar joints) is illustrated, following the strategy to assess a respectful, recognisable and reversible consolidation technique. Moreover, aspects of management of works and of modelling from structural point of view are discussed.
    Keywords: archaeological consolidation; three R strategy; UNESCO sites; masonry structures.
    DOI: 10.1504/IJMRI.2022.10048711
     

Special Issue on: Recent Trends in Historic Masonry Building Assessment Principles, Models, Methods, and Practices

  • Dynamic characterisation and numerical model updating of a historical complex   Order a copy of this article
    by Gianluca Standoli, Angela Ferrante, Ersilia Giordano, Francesca Bianconi, Francesco Clementi 
    Abstract: The world is full of historical structures that must be preserved. Given their considerable value, nothing or minimally invasive techniques must be adopted to monitor their health and improve their structural capacity. The Operation Modal Analysis (OMA) is currently the most popular non-invasive methodology to monitor them. Indeed, it allows to derive the dynamic characteristics of the structures through acceleration appropriately positioned sensors. The OMA is employed in the current paper to study a historical complex in the Marche region hinterland (central Italy). First, the dynamic monitoring is carried out to extract the dynamic parameters of the structure. The obtained data are then employed to realize a realistic numerical model by acting on uncertain parameters such as boundary conditions and material parameters.
    Keywords: masonry tower; monumental building; structural health monitoring; operational modal analysis; finite element model; model updating.
    DOI: 10.1504/IJMRI.2022.10052102
     
  • Garisenda Tower in Bologna (Italy): structural assessment and numerical simulation   Order a copy of this article
    by Angelo Di Tommaso, Gian Carlo Olivetti, Giuseppe Lacidogna, Stefano Invernizzi, Alberto Carpinteri 
    Abstract: The Garisenda Tower in Bologna is a city symbol and one of the most valuable medieval heritages. The tower was built on compressible soils and suffered from the very beginning for increasing tilting. For this reason, Dante Alighieri refers to the tower to describe the fear caused by the giant Antaeus bending over him when he tries to descend from the eighth to the ninth circle of hell, in the Divina Commedia. Consequently, the tower has always deserved special attentions to preserve its structural safety. The paper describes some of the most recent results obtained from non-destructive monitoring techniques and presents a finite element model suitable to represent the structural behaviour of the tower, included the effect of thermal deformation.
    Keywords: cultural heritage; masonry tower; non-destructive techniques monitoring; finite element modelling; structural assessment.
    DOI: 10.1504/IJMRI.2023.10053441
     
  • Masonry arches simulations using cohesion parameter as code enrichment for limit analysis approach   Order a copy of this article
    by Bledian Nela, Alejandro Jimenez Rios, Marco Pingaro, Emanuele Reccia, Patrizia Trovalusci 
    Abstract: Masonry structures are highly vulnerable to natural hazards, therefore both traditional and composite materials have been used as reinforcements to provide different solutions. Extensive effort is done to develop appropriate techniques of assessment, that usually demand an individualised methodology of analysis to be handled through comparative studies requiring results validation. A suitable field of study is the limit analysis approach towards masonry structures, as it offers quite accurate and, more importantly, robust results. Enrichment of a limit analysis homemade code with the inclusion of cohesion and frictional behaviour at the interface resolves, in a simplified but very robust manner, the perplexing issues involved with the numerical assessment of such structures with reference to arches. The cohesion incorporation is calibrated for a variety of in-plane applications simulating the strengthening measures. Results obtained are validated with literature results and included in a comparative study between discrete numerical models that utilise different strategies.
    Keywords: limit analysis; friction; no-tension contacts; cohesion; reinforced masonry arches.
    DOI: 10.1504/IJMRI.2023.10053576
     
  • Out-of-plane seismic response of a masonry facade using distinct element methods   Order a copy of this article
    by Mattia Schiavoni, Angela Ferrante, Georgios Panagiotis Salachoris, Chiara Mariotti, Francesco Clementi 
    Abstract: Damage surveys after earthquakes showed that unreinforced masonry buildings are prone to local failure modes related to out-of-plane mechanisms of walls caused by the poor connection with the orthogonal walls. Otherwise, if the masonry element rises isolated it may be subject to overturning mechanisms rather than in-plane collapse. Nowadays, several methods can be used to evaluate collapses. These methods require quite a high computational cost, not beneficial to practitioners. Advanced numerical models can be applied, such as the discrete element and non-smooth contact dynamics methods, which treat the masonry as a set of either rigid or deformable blocks that can slide and impact each other. In this paper, an ancient (isolated) masonry wall is analysed, and the results provide the first comparison between two numerical models to estimate the influence of the intervention placed on the top of the wall.
    Keywords: masonry wall; nonlinear dynamic analyses; non-smooth contact dynamics method; NSCD; damage cumulation; restoration interventions.
    DOI: 10.1504/IJMRI.2022.10051745
     
  • A new non-invasive method for the seismic retrofit of rubble masonry using composite connectors   Order a copy of this article
    by Gianmarco De Felice, Stefano De Santis, Omar AlShawa, Domenico Liberatore, Luigi Sorrentino, Ivan Roselli, Marialuigia Sangirardi 
    Abstract: With the aim of developing a new method for enhancing the seismic performance of historic rubble stone masonry, a shake table investigation was carried out on a full-scale wall retrofitted with non-crossing carbon fibre reinforced polymer (CFRP) connectors inserted through the stones of the facade. The wall was built with the stones collected in a small village struck by the 2016-2017 seismic sequence in Central Italy and subject to natural earthquake records, applied in vertical and horizontal directions with increasing intensity up to collapse. The novel non-invasive system effectively prevented masonry disintegration and leaf separation, entailing a significant improvement of its seismic capacity with respect to an unstrengthened specimen tested for reference. The impact of the retrofitting work is minimised because the fair face of the masonry is preserved and the installation of CFRP connectors is performed only from outside.
    Keywords: fair faced masonry; leaf separation; masonry disintegration; shake table investigation; stone masonry; vertical bending.
    DOI: 10.1504/IJMRI.2022.10051746
     
  • Modelling of in-plane strengthening of unreinforced masonry buildings: a numerical comparison between traditional and FRCM jacketing   Order a copy of this article
    by Luca Sbrogiò, Ylenia Saretta, Maria Rosa Valluzzi 
    Abstract: The in-plane seismic strengthening of masonry walls often resorts to the jacketing technique; over time steel rebar and shotcrete systems (SRC) have been replaced by fibre reinforced material and cementitious mortars (FRCMs). Equivalent frame models (EFMs) are a viable option for the assessment of existing masonry buildings and estimating the effects of the strengthening. The paper proposes a numerical evaluation of the effect on seismic capacity of SRC and FRCM jacketing as a function of the modelling strategy (equivalent coefficient or modification of the nonlinear behaviour) and the scale of the problem, from a single wall to a simple masonry building. The analytical strength domains of the wall are compared to the results of pushover analyses in a FME model showing a different seismic behaviour at low and high vertical loads. At the building scale, pushover curves show strength and ductility increments which are comparable to the changes in the nonlinear behaviour of the walls induced by the strengthening, as observed in the analytical domains; the results are compared to the available literature.
    Keywords: jacketing; reinforced concrete; fibre reinforced cementitious matrix; FRCM; modelling; in-plane strengthening; masonry buildings.
    DOI: 10.1504/IJMRI.2022.10052156
     
  • Non-destructive testing and historic building information modelling for the structural diagnosis of the church of the society of Jesus in Cusco, Peru   Order a copy of this article
    by Rony Reategui, César Chácara, Guido Silva, Mauricio Gonzales, Carlos Yaya, Diego Villagómez, Adriana Scaletti, Benjamín Castañeda, Rafael Aguilar 
    Abstract: This paper aims at presenting the results of a set of non-destructive tests (NDT) applied to an emblematic stone masonry church and the generation of a 3D parametric model to store and visualise structural diagnosis information following the historic building information modelling (HBIM) framework. Reverse engineering techniques were applied to obtain a precise point cloud of the church. NDT results exposed that the church currently presents several structural anomalies such as cracks, efflorescence, and moisture, among others. In addition, the mechanical characterisation showed that the masonry walls and pillars have an elasticity modulus within the expected range. Furthermore, with the application of operational modal analysis (OMA), it was possible to identify three modes of vibration of the structure. The representation of all the non-geometric information inside the HBIM model plus the generation of a custom plugin allowed the visualisation and adequately managing of the structural diagnosis information of the project.
    Keywords: historical buildings; stone masonry; geometrical survey; sonic tests; operational modal analysis; OMA; infrared thermography tests; HBIM; Peru.
    DOI: 10.1504/IJMRI.2022.10052206
     
  • Structural health monitoring of a masonry arch bridge: modal identification and model updating   Order a copy of this article
    by Giacomo Zini, Michele Betti, Gianni Bartoli, Salvatore Giacomo Morano, Paolo Spinelli 
    Abstract: Historic masonry arch bridges are widespread across the European countries and the assessment of their current safety under operative conditions is a hard task. The dynamic loads due to the vehicular traffic and the degradation of the materials, often speeded up by harsh environmental conditions and scarce maintenance, may leads to critical situations. As a consequence, the scientific community is working in order to develop and propose reliable methodologies of analysis and non-invasive technologies of investigation to assess their current state of conservation. In this respect, this paper discusses an experimental activity performed in a two-span historic masonry arch bridge. Output-only modal identification was carried out both in time and frequency domains using the stochastic subspace iteration (SSI) and the frequency domain decomposition (FDD), respectively. The results provided by the two procedures are first compared, and subsequently employed for FE modal updating. To calibrate the FE model an optimisation approach based on genetic algorithms (GAs) was employed.
    Keywords: historic bridge SHM; FE modelling; output-only identification; model updating.
    DOI: 10.1504/IJMRI.2022.10052514
     
  • Experimental and numerical procedure for vulnerability assessment of historical masonry building aggregates   Order a copy of this article
    by Giosuè Boscato, Jacopo Baldelli, Daniele Baraldi, Claudia De Carvalho Bello, Antonella Cecchi 
    Abstract: Historic buildings are a substantial part of the Italian architectural heritage; hence, standard procedure is necessary to evaluate the global and local vulnerabilities. The heterogeneity of materials and technologies combined with the complex volumetric shape of the building aggregates that is constituted by several structural typologies make the definition of a standard approach a hard challenge. This work reports two case studies of rural aggregate buildings. The complex systems were examined both with local and global tests by sonic and dynamic identification. Sonic tests were carried out on representative structural elements, while the dynamic identification considered the volume interaction by modal shapes and related frequencies. For both experimental techniques, a parametric analysis was carried out on results to define reliable 2D and 3D numerical models. This paper provides the formulation of a simplified approach of a 2D FE model based on experimental data to identify potential failure mechanisms.
    Keywords: structural health monitoring; non-destructive tests; modal analysis; OMA; vulnerability assessment.
    DOI: 10.1504/IJMRI.2022.10052659
     
  • Garisenda Tower in Bologna (Italy): health monitoring by different nondestructive testing techniques   Order a copy of this article
    by Angelo Di Tommaso, Gian Carlo Olivetti, Giuseppe Lacidogna, Stefano Invernizzi, Oscar Borla, Alberto Carpinteri 
    Abstract: In the Garisenda Tower of Bologna, several non-destructive (NDT) techniques are being used to examine structural damage and cracking evolution. The acoustic emission (AE) activity emerging from the masonry structures is analyzed and related to surrounding temperature and strain measurements by distributed fibre optic sensors (FOSs). A seismometer was used to monitor low-frequency vibrations propagating across the ground-building foundation interface in order to examine the impact of local seismic activity or heavy vehicle traffic on tower vibration. The obtained data has led to the identification of several sources of AE activity, which apparently indicates the existence of an evolving cracking pattern. A consistent increase in the cumulated function of AE signals suggests that tower damage is caused by more than temperature changes. As a result, the origin of damage can be identified as the material's time-dependent creep behaviour under dead load and its interaction with fatigue generated by thermal fluctuations.
    Keywords: non-destructive techniques; acoustic emission; fibre optic sensors; FOSs; seismicity; medieval towers; Italy.
    DOI: 10.1504/IJMRI.2023.10053442
     
  • Motion magnification technique for the monitoring of masonry structures   Order a copy of this article
    by Martina Modesti, Cristina Gentilini 
    Abstract: Motion magnification (MM) is a recently introduced technique that allows displaying small structural vibrations, otherwise imperceptible to the naked eye, by amplifying movements from videos taken with common cameras. Vibrations of structures caused by micro-earthquakes, such as traffic-induced tremors, are perceived through pixels comparison in video frames as their intensity is increased so that they become visible. Motion magnification analysis allows to identify which parts of the building are most vulnerable to earthquakes and to determine structural natural frequencies. Three simple structures are first considered to check the method reliability, then the technique is applied to different structures in situ as bell towers as well as bridges. The results show a clear correspondence between the theoretical frequencies of vibration and those identified by the processed videos. As such, motion magnification can be considered as a valid tool for a non-invasive, fast and low-cost analysis of the dynamic characteristics of buildings.
    Keywords: motion magnification; masonry structures; mode shapes; natural frequencies; video frames; amplification; structural vibrations; amplified movements.
    DOI: 10.1504/IJMRI.2023.10053443
     
  • FE modelling for the nonlinear dynamics of a historic tower in Central Italy   Order a copy of this article
    by Angela Ferrante, Ersilia Giordano, Gianluca Standoli, Mattia Schiavoni, Francesco Clementi 
    Abstract: The dynamics of a medieval tower, on the upper side of San Severino Marche (Central Italy), subjected to transversal dynamic loadings was analysed. An advanced numerical model is utilised to have an insight into the modalities of progressive damage of the structure under strong nonlinear dynamic excitations, namely the FE concrete damage plasticity (CDP) model. A full 3D detailed discretisation is adopted. From the numerical results, both the role played by the actual geometries and the insufficient resistance of the constituent materials are envisaged, showing a good match with crack patterns observed after the seismic sequence of 2016-2017.
    Keywords: masonry tower; architectural heritage; nonlinear dynamic analysis; finite element method; concrete damage plasticity; CDP.
    DOI: 10.1504/IJMRI.2023.10053943
     

Special Issue on: Composite Materials for Masonry Strengthening Experiments, Modelling and Analysis

  • Historical masonry wallets with plaster slabs strengthened by CrFRM and GFRP   Order a copy of this article
    by Roberto Capozucca, Erica Magagnini 
    Abstract: Knowledge concerning the response of historic masonry to cyclic shear loading is fundamental for defining the behaviour of existing masonry buildings under seismic actions. Walls under cycle shear as known may be diagonally cracked due to low tensile strength of masonry. Many mechanical and geometric parameters influence the shear response of brickwork walls. One aspect too often underestimated is the presence of plaster on the external surface of walls. In this paper, experimental response and failure mechanisms of historic brickwork wallets, without plaster and with lime plaster reinforced by fibres, have been investigated under tensile tests by diagonal compression. The wallets have been strengthened with mortar reinforced by chrome fibres (CrFRM) and with glass fibre reinforced polymer (GFRP) net. The experiments were carried out previously on materials and triplets to define the strength of unreinforced masonry under compression and shear. Experimental results are shown, obtaining shear criteria useful in practice.
    Keywords: historic masonry; plaster slab; chrome fibres; CrFRM; glass fibre reinforced polymer; GFRP-net; diagonal compression tests.
    DOI: 10.1504/IJMRI.2022.10044372
     
  • Application of digital image correlation to compression tests on tuff masonry panels strengthened by textile reinforced mortar   Order a copy of this article
    by Gianluca Maracchini, Gianluca Chiappini, Jacopo Donnini, Enrico Quagliarini, Valeria Corinaldesi, Stefano Lenci 
    Abstract: Digital image correlation (DIC) is a contactless full-field optical technique for measuring displacements that can be potentially used in place of more common linear variable differential transformers (LVDTs) to avoid instrumentation damage during destructive tests. However, despite being already adopted in several fields, its potentialities in testing full-scale masonry walls strengthened with textile reinforcing mortar (TRM) have not been fully investigated yet. In this paper, the results obtained by applying a stereo-DIC technique to compression tests of unstrengthened and TRM-strengthened tuff masonry walls (1.0 x 1.2 x 0.25 m3) are reported. Results showed that the presence of helical steel bars used to connect the two TRM layers caused crack localisation to the masonry wall, leading to a reduction of compression strength. Compared with the results obtained with LVDTs, the DIC technique was able to accurately monitor tridimensional displacements and cracking pattern evolution. The potentialities and limits of this technique are finally highlighted.
    Keywords: digital image correlation; DIC; textile reinforcing mortar; TRM; tuff masonry; compression test; elastic modulus.
    DOI: 10.1504/IJMRI.2022.10045349
     
  • Effect of type of masonry units on the mechanical properties of masonry panel walls   Order a copy of this article
    by Ali Abdelkhalek, Mohammed A.Sakr, Ayman A. Seleemah, Tarek M. Khalifa 
    Abstract: Recently, cellular lightweight concrete (CLC) masonry units have been emerging as a substitute for burnt red clay (RCL) units that are commonly used in construction. In this study, an experimental program was conducted according to ASTM and British standards to compare the essential in-plane mechanical properties of CLC and RCL masonry units and masonry panels. These mechanical properties represent the initial inputs for numerical modelling used in analysing the behaviour of different elements (i.e., constructed from CLC units). This study showed that RCL masonry units and masonry panel walls are stiffer than CLC units, but they approximately have the same lateral load resistance. While the CLC masonry units are more ductile than RCL ones and have higher energy-absorbing capacity. Accordingly, they could be a solution to enhance the flexibility and ductility of buildings. Moreover, it is a lightweight brick.
    Keywords: cellular lightweight concrete; mechanical properties; red clay masonry units; masonry structures; compressive strength.
    DOI: 10.1504/IJMRI.2022.10046886
     
  • Fully analytical model for the analysis of externally bonded composites applied to brittle supports: sensitivity analysis   Order a copy of this article
    by Elisa Bertolesi, Gabriele Milani, Ernesto Grande, Roberto Capozucca 
    Abstract: Several analytical models have been proposed reducing the debonding mechanism to a bond loss event occurring in inelastic interfaces, whose mechanical properties need to be adjusted based on available experimental data. The analytical model developed by the authors and briefly recalled in this work, considers an elastic FRP bonded to brittle supports by means of inelastic interfaces. In detail, the inelastic interface is described by an initial linear elastic phase (phase 1) and a decreasing exponential softening law (phase 2). This article demonstrates the reliability of the proposed model to study the adhesion performance and failure modes of FRPs applied on different brittle supports. The model is widely benchmarked using the results obtained from two laboratory investigations on flat concrete and masonry prisms reinforced with FRP composite materials and an extensive sensitivity analysis performed by varying different parameters, namely: bond length, interfacial bonding law and FRP mechanical properties. Each parameter is discussed with respect to: 1) the obtained global force-slip curves; 2) force increase; 3) post-peak response.
    Keywords: debonding mechanisms; FRP composites; closed form solution; concrete; masonry.
    DOI: 10.1504/IJMRI.2022.10046887
     
  • Dynamic identification and numerical model updating of an old bell-tower in Marche Region (Italy)   Order a copy of this article
    by Ersilia Giordano, Angela Ferrante, Georgios P. Salachoris, Mattia Schiavoni, Francesco Clementi, Stefano Lenci 
    Abstract: In this paper, the dynamic characterisation of the civic bell-tower of Rotella (a small village in the Marche region, Central Italy) is presented. The tower after being monitored, using four tri-axial piezo-electric accelerometers, and obtaining its dynamic characteristics, was modelled through a finite element software. The difference between measured and real values has been smoothed out by acting on all unknown parameters such as Young’s moduli, thus obtaining a model with frequency differences, compared to reality, less than 5% and the MAC values between the modal shapes close to the unit.
    Keywords: dynamic identification; numerical models; masonry towers; monumental buildings; structural health monitoring; finite element model; FEM; model updating; modal assurance criteria; Marche Region; Italy.
    DOI: 10.1504/IJMRI.2022.10046888
     
  • Unveiling the complexity of twin church bells dynamics using ambient vibration tests   Order a copy of this article
    by Angela Ferrante, Ersilia Giordano, Gianluca Standoli, Francesca Bianconi, Francesco Clementi, Stefano Lenci 
    Abstract: On the Italian territory, there are many monumental structures that need to be preserved. Given their great historical and architectural value, it is essential to use minimally invasive, but effective, techniques able to evaluate their current structural capabilities and monitor their structural health. The technique that currently appears most appropriate is the ambient vibration monitoring, which, through the analysis of recorded accelerometric time-histories in operating conditions, returns the current dynamic properties of the structure. This work shows the results of the short-term monitoring carried out on the two towers of the San Francesco Church, located in the city of Ascoli Piceno. Modal identification allowed to obtain its frequencies, modal shapes, and damping. With these data, the finite element model of the complex was calibrated, acting on the elastic parameters of the masonry, making numerical modal shapes and frequencies match with the experimental results.
    Keywords: dynamic identification; numerical models; NM; masonry churches; masonry towers; ambient vibration tests; monumental structures; structural health monitoring; SHM; finite element model; model updating.
    DOI: 10.1504/IJMRI.2022.10046889
     
  • ConFiRMa: calibration of a numerical model for fibre-reinforced mortar analysis with OOFEM code   Order a copy of this article
    by Ingrid Boem, Bořek Patzák, Alena Kohoutková 
    Abstract: The 'conFiRMa' project is aimed at calibrating a numerical model for masonry buildings strengthened with fibre reinforced mortar (FRM). The main purpose is to develop a multi-level approach, starting with the detailed modelling of components, followed by an optimisation procedure to get a computationally efficient intermediate level model for the calibration of the lumped plasticity model for global analysis. In this paper, the first results concerning the detailed modelling level are presented. It focuses on the interaction between the mortar matrix and the embedded composite reinforcement mesh. The mortar is modelled through solid elements, the yarns of the fibre-based mesh with truss elements and the mortar-mesh interaction by means of interface elements. Nonlinear static analyses are performed, considering the materials and interfaces nonlinearity. The results of previous experimental tests concerning FRM mechanical characterisation are considered to calibrate (pull-off tests) and validate (tensile and shear bond tests) the numerical model.
    Keywords: seismic vulnerability; masonry strengthening; structural refurbishment; composites; fibre reinforced mortar; FRM; composite reinforced mortar; CRM; numerical modelling; OOFEM.
    DOI: 10.1504/IJMRI.2022.10046890