International Journal of Masonry Research and Innovation (50 papers in press)

Regular Issues

• Shrinkage and creep behaviour of thin layered mortared masonry  
  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 studies on blast performance of unreinforced masonry walls of clay bricks and concrete blocks: a state-of-the-art review  
  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  
  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  
  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  
  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  
  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  
  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  
  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  
  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  
  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  
  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  
  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  
  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  
  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  
  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  
  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
   
  
• Explosions and mechanism of blast loading: a review  
  by S.M. Anas, Mehtab Alam, Mohammad Umair, Farman Saifi, Mohd Haris, Mohd Shariq, Manal Hadi Ghaffoori Kanaan 
  Abstract: In contemporary society, industrialisation and the rising of terrorism threats highlight the necessity and importance of structural protection against industrial and intentional blast explosions. The need to protect people and infrastructures from high-intensity dynamic loadings such as blast and shock waves has been stimulating interest in the development of new, adaptive, and more intelligent approaches to the protection of structures and to the development of armour. To predict the behaviour of the structure under explosion loads, blast load analysis needs to be done. This review paper presents an overview of explosives and their properties, pressure-impulse diagrams, performance criteria, current design approaches, computational methods, characteristics, estimation methods of blast loads for free-air and surface burst scenarios, and blast-wave clearing behaviour. Details about blast wave propagation and peak overpressure are explained. The paper presents the basics of blasts for beginner researchers and structural engineers to understand such extreme loading scenarios.
  Keywords: blast; explosives; explicit analysis; free-air burst; implicit analysis; pressure-impulse plots; peak overpressure; structures; surface burst; blast wave effects.
  DOI: 10.1504/IJMRI.2023.10054212
   
  
• Role of carbon steel hollow tubes in-lieu of conventional steel re-bars on the anti-blast performance of RC slab of standard concrete externally strengthened with metallic foam  
  by S.M. Anas, Mehtab Alam, Ajmal Paktiawal, Mohammad Umair 
  Abstract: 3D numerical model of a one-way slab of standard concrete of static compressive strength 39.50MPa doubly reinforced with conventional steel bars of yield strength 600 MPa is developed in ABAQUS software and validated against blast test results/observations available in the literature. To improve slab performance, conventional-bars are replaced with equivalent carbon steel hollow tubes on the: 1) tension side; 2) compression side only; 3) both faces of the slab. Results showed that the reduction of deflection and damage is maximum for the complete replacement of conventional bars by the tubes on both faces of the slab, yet full substitution by the tubes on the tension side only possesses higher cracking resistance under blast loading. To further excel the blast performance, the slab is externally strengthened with aluminium foam layer/s. It was concluded that the double layer of the foam dissipates maximum explosion energy and significantly improves the slab performance.
  Keywords: aluminium foam; ABAQUS; blast loading; carbon steel tubes; damage; close-range explosion; TNT; finite element modelling; RC slabs.
  DOI: 10.1504/IJMRI.2023.10054213
   
  
• Performance prediction of axially loaded unreinforced masonry wall strengthened with (1) cement-mortar plaster, (2) Ferro-cement, and (3) C-FRP laminate, under blast loading  
  by Mohd Shariq, Mehtab Alam, S.M. Anas, Mirza Aamir Baig, Asif Hussain 
  Abstract: Sufficient research work is available on free-standing braced as well as unbraced masonry walls subjected to explosive loading. However, the response of strengthened masonry walls carrying various axial loads and subjected to blast loading is not very well investigated. In this work, different strengthening techniques such as: 1) cement-mortar plaster; 2) Ferro-cement; 3) CFRP laminate are considered for blast performance enhancement of unreinforced masonry wall, 5,000 x 2,800 x 230 mm3, made of clay bricks, carrying axial compression of 51, 30, and 9 kN/m corresponding to axial load on 1st, 2nd, and 3rd storey walls of a three-storey masonry building, respectively. A high-fidelity finite-elements code, ABAQUS with an inbuilt explicit module and concrete damage plasticity model is used for the blast simulations. Walls have been modelled following detailed micro-modelling. Results show that 1 mm thick CFRP laminate on both the faces of the wall is found to give the best performance.
  Keywords: blast load; unreinforced masonry; URM; plaster; Ferro-cement; CFRP; damage; dissipated energy.
  DOI: 10.1504/IJMRI.2023.10055673
   
  
• The mediating role of sustainability and quality on the relationship between management practices and risks management in construction industry  
  by Bassam S. Mansour, Janani Selvam, Amiya Bhaumik 
  Abstract: The success of society’s efforts to achieve sustainable progress is directly reliant on the building sector. The purpose of such a research aims to investigate the influence of managing practices affecting risks control in the constructions sector in Palestine, as well as the influence that qualities and sustain abilities play as mediators. Two cases studies were prepared with X and Y companies. The study showed that there is an impact of management practices on the quality, sustainability and risk management, also, there is an impact of sustainability and quality on the risks management, besides, the sustainability concept, which provides a function in mediating the interaction between managerial practices as well as risk managing, has an effect on that interaction that perhaps the company’s profit may be increased by the use of managing methods that take into account comprehensive qualitative management and enable it to face challenges.
  Keywords: sustainability; total quality management; TQM; risk management; management practices and construction industry.
  DOI: 10.1504/IJMRI.2023.10056666
   
  
• The role of sustainability and quality on the relationship between management practices and risks management in construction industry  
  by Bassam S. Mansour, Janani Selvam, Amiya Bhaumik 
  Abstract: Sustainability in society is largely dependent on the building sector. This research aimed to examine the mediating function of sustainability and quality in the relationship between management practises and risk management in the construction industry in the Gaza Strip. A small sample of 30 forms was used to conduct preliminary research on the questionnaire. Sixty-one factors, broken down into four classes, were found by a survey questionnaire. 110 questionnaires were distributed and received as follows: 87 (79%) from contractors and consultants as respondents. According to the results, management practises have an effect on quality, sustainability, and risk management; sustainability has an effect on the relationship between management practises and risk management; and quality and sustainability both have effects on risk management. The survey showed that having quality management practices helps to overcome work risks and problems; as well, it helps in providing sustainable work services.
  Keywords: sustainability; total quality management; TQM; risk management; human resources management; construction industry.
  DOI: 10.1504/IJMRI.2023.10056673
   
  
• Evaluation of the load carrying capacity of cold formed steel stiffened web section  
  by Janani Selvam 
  Abstract: The proposed system investigates, during radial compaction, the influence that network stiffness has on values along with the behaviours of freeze iron portal frames that include various forms of border stringers. The results of the tests give irrefutable proof that the basic component simulations are correct. In this study, the localised, deformations, as well as torsional buckling failures modes, as well as the interconnections between these failing modes, are uncovered. A comparative study is made among the beams ability that was anticipated by the parametric assessment as well as the marginal power that was calculated for cold formed structural steel by implementing the widely available methodology. This was done to determine whether or not the generalised assessment accurately anticipated the piers capabilities. We do an investigation into the reliability of this method and provide a recommendation on an acceptable adjustment variable.
  Keywords: stiffened web section; load carrying capacity; ANSYS.
  DOI: 10.1504/IJMRI.2023.10056765
   
  
• Process parameter mix design approach and analysis of variance of fly ash-lime-gypsum masonry bricks by Taguchis method  
  by Mohammed Rihan Maaze, Sandeep Shrivastava 
  Abstract: Environmental and economic considerations of manufacturing bricks play an essential role in the growth of sustainable construction. The present study investigates the optimisation of the mix design of fly ash-lime-gypsum (FaL-G) bricks by Taguchi’s process parameter approach. Experiments have been designed using L9 orthogonal arrays with three factors and three levels. Mechanical and physical properties of brick mix were investigated. Compressive strength was maximised by considering the larger-the-better condition. Analysis of variance (ANOVA) was performed on a mix, and its significance levels are presented in this paper. According to the orthogonal array design of the experiment, fly ash (50%), lime (25%), and water to binder (W/B) ratio (0.38) were the optimal levels to have maximum compressive strength. Additionally, microstructural studies like SEM, XRD and TG analysis were performed to study the optimum mix’s morphology, phase structure and thermal resistance.
  Keywords: fly ash; FaL-G bricks; process design approach; maximisation; compressive strength.
  DOI: 10.1504/IJMRI.2023.10057871
   
  
• Effect of infill masonry wall with central opening on seismic behaviour of reinforced concrete structure  
  by Sayed Qudratullah Sharafi, Taiki Saito 
  Abstract: Un-reinforced masonry walls are commonly used as partition walls inside the reinforced concrete (RC) buildings in most of the countries. Although, the infill masonry walls are not accounted in structural design process (non-structural elements) but they can significantly change the seismic performance of structures such as strength, stiffness, story drift and energy dissipation. Several analytical and experimental research have been performed to find out the influence of infill masonry walls with opening inside the RC structure, by changing the opening location, opening size, aspect ratio of opening, infill wall connection with frame, material properties and so on. The current research aims to propose a new method (net area of masonry wall and average struts angle) to estimate the capacity of infill masonry wall with central opening and study the effect on the seismic performance of the RC structure. The shear strength of the infill masonry obtained by the proposed method was compared with experimental results as well as with the analysis methods to confirm its accuracy. The nonlinear frame analysis program, STERA 3D, developed by one of the authors was used for the analysis.
  Keywords: RC structure; infill masonry; opening; shear strength; earthquake response analysis.
  DOI: 10.1504/IJMRI.2023.10059213
   
  
• Study on the influence of structural interventions to monuments based on in-situ ambient vibration measurements at Matsopoulos Mill, Trikala, Greece  
  by Thomas N. Salonikios, Konstantinos E. Morfidis, Nikolaos P. Theodoulidis 
  Abstract: In the 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
   
  
• Influence of masonry infill configuration on seismic response in RC frame structures over soft and medium soil conditions  
  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 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
   
  
• Valuation on the strength properties of gypsum based PCM cement mortar  
  by D. Gift Pon Lazarus, Sunita Bansal 
  Abstract: The construction industry is rapidly moving towards developing sustainable and smart building materials in recent decades due to the population range and the rising living comfort standards. In this study the compressive strength gypsum-based PCM cement mortar is 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 and make gypsum with PCM aggregates. It is also used as a replacement for fine aggregates used in cement mortar. In order to use PPC cement, quartz sand, gypsum with PCM aggregates, 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  
  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 five 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
   
  
• Experimental assessment of diagonal shear parameters of dry stacked block masonry built with self-interlocking compressed earth blocks  
  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
   
  

Special Issue on: ICoNSoM 2022 Non-Linear Behaviour Of Vaulted Masonry Structures

• On the construction stage analysis of historical masonry vaults  
  by Marco Zucca, Emanuele Reccia, Flavio Stochino, Antonio Maria Cazzani 
  Abstract: A growing interest in the preservation of historical masonry constructions led to analysing in detail the structural behaviour of masonry vaults. In the last decades, several approaches have been proposed to analyse vaults behaviour under static and dynamic loads, which depends on different parameters such as shape, mechanical properties of masonry and brick patterns. In this paper, the static behaviour of a historical masonry sail vault, characterised by a complex brick pattern and by a segmental shape, is analysed. Such typology of vaults is widely diffused in the area of Cagliari, where many of them have been built during the XIX century. Some hypotheses about the constructive techniques adopted are investigated. In particular, the role played by the arrangement of the bricks is considered. The purpose is to check whether the adopted bricks pattern allows construction of vaults without formwork. Starting from a geometry model which has been reconstructed from a complete laser scanner survey, a finite element model is developed to perform a construction stage analysis. Thus, the evolution of the stresses acting on the different parts composing the vaults during the construction process is studied, assuming that no formwork has been used.
  Keywords: masonry vaults; segmental shape; brick patterns; construction stage analysis.
  DOI: 10.1504/IJMRI.2023.10054537
   
  
• Experimental and numerical analyses of curvilinear masonry structures exposed to high temperatures  
  by Alessandro P. Fantilli, Nicholas S. Burello 
  Abstract: Despite masonry arches and vaults are recurring structural members within architectural heritage, experimental and numerical analyses on these structures exposed to fire are still not much addressed. The present paper deals with five tests carried out on masonry barrel vaults, made with clay solid bricks, cement-lime mortar, and subjected to standard fire at intrados and to different load arrangements on the extrados. Two vaults were also insulated with fire protectives to mitigate the effects of elevated temperatures. In addition, a simplified numerical model, previously introduced and herein improved with a more refined thermal analysis, is used to calculate the fire resistance R. As results, by comparing the test data and the numerical outcomes, more reliable, but still conservative, predictions of R can be obtained in the case of barrel vaults.
  Keywords: arches; vaults; structural design; limit analysis; resisting area; standard fire; fire insulating; fire protective; clay masonry.
  DOI: 10.1504/IJMRI.2023.10055405
   
  
• Numerical investigation of the post-elastic seismic response of the multi-vaulted Beit-El-Din Hammam  
  by Amal Gerges, Maria Cristina Porcu, Antonio Cazzani 
  Abstract: The Beit-El-Din Hammam is a Lebanese masonry monument characterised by vaults pierced by holes. Despite its huge importance for the Lebanese heritage, the vulnerability of this monument to exceptional actions has not yet been assessed. The present study aims to contribute to filling this gap by carrying out a dedicated dynamic numerical investigation. Environmental modal tests were carried out to find the natural frequencies, through which a detailed 3D model was identified. Nonlinear dynamic analyses under spectrum-consistent earthquakes were performed, where the inelastic behaviour of the masonry was described through a concrete damage plasticity model. The results of the study predicted the damage pattern that could affect the monument. A twin model led to assessing the effect of holes on the tensile damage of vaults. The paper offers a contribution to the debate on the post-elastic and ductile behaviour of masonry Hammams with multi-holed vaults, typical structures in Arabic countries.
  Keywords: holed masonry vaults; nonlinear dynamic analysis; masonry hammam; seismic vulnerability of historical buildings; seismic damage.
  DOI: 10.1504/IJMRI.2023.10058266
   
  
• Micromechanical modeling of masonry domes accounting for damage and friction phenomena  
  by Daniela Addessi, Cristina Gatta, Elio Sacco 
  Abstract: This paper investigates the mechanical response of masonry domes to improve evaluation of their structural capacity. Numerical simulations are performed considering a small-scale specimen. A micromechanical modelling approach is adopted, where each masonry constituent is separately modelled and all the information about the microstructure are considered. Linear elastic bricks, discretised with three-dimensional solid finite elements, are connected to each other with interfaces representing mortar joints and their interaction behaviour with the bricks. For the interfaces, modelled with 4+4 node elements, a damage-friction constitutive law is assumed, able to track the microcracking evolution due to tensile and shear states. Firstly, the experimental response of the dome under vertical load is reproduced exploiting the ideal symmetry conditions of the structure. Then, the effect of the variation of masonry texture is investigated. Finally, the dome behaviour is studied under horizontal actions mimicking seismic excitation. Response curves and failure mechanisms are monitored.
  Keywords: masonry dome; damage-friction; interfaces; micromechanical modelling; finite element.
  DOI: 10.1504/IJMRI.2023.10058769
   
  
• Closed form solutions in limit analysis for masonry cloister vaults and domes subjected to concentrated vertical loads applied at the top crown  
  by Gabriele Milani 
  Abstract: Two cases technically relevant are investigated in the field of the prediction of the load carrying capacity of masonry double curvature structural elements, namely hemispherical domes and square cloister vaults subjected to concentrated vertical loads at the top crown. Such loading condition is encountered quite frequently in practice, for instance for domes with lanterns and for cloister vaults belonging to historical buildings loaded in the middle span. A failure mechanism is hypothesised and analytical expressions for the different contributions in the internal and external power dissipation are deduced. The collapse multiplier is then obtained through the application of the principle of virtual powers. The advantage stands in the applicability of the method for a large variety of domes and cloister vaults (with a generalisation to additional special conditions, such as for instance in case of elliptic and rectangular in-plane geometries, presence of oculi and so on). The approach proposed is benchmarked on two case-studies experimentally tested, for which several numerical results coming from different models are already available.
  Keywords: masonry domes and cloister vaults; kinematic limit analysis; closed form solutions; axi-symmetric loads.
  DOI: 10.1504/IJMRI.2023.10058815
   
  

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  
  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  
  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
   
  
• Damage assessment of Apennine masonry churches severely damaged during the 2016 Central Italy seismic sequence  
  by Ersilia Giordano, Georgios Panagiotis Salachoris, Francesca Bianconi, Francesco Clementi, Stefano Lenci 
  Abstract: The masonry churches in the Apennine area of Central Italy were severely affected by the 2016 earthquakes. The damages of some of these are analysed by considering their typical features such as slender walls, bell-gables, vaults, etc. The behaviours exhibited by these churches are compared with the numerical results on 3D Finite Element Models. This study aims to show how the role of geometry and irregularities present in the structures are fundamental in the analysis of local and global behaviours. Another objective is to investigate the applicability of the non-linear approach recommended by manuals and codes. This work confirms that with the usual non-linear static analysis, despite the approximations introduced in the models, it is possible to identify (qualitative way) the critical areas of the structure that could trigger collapses. Therefore, this type of analysis shows, once again, to be a suitable tool for planning interventions to preserve the heritage.
  Keywords: masonry churches; damages; collapses; seismic sequence; eigenvalues analyses; nonlinear static analyses; 3D finite element models; Italy.
  DOI: 10.1504/IJMRI.2023.10054072
   
  
• Sensitivity to uncertainties in the dynamic response of masonry arches  
  by Massimiliano Lucchesi, Barbara Pintucchi, Nicola Zani 
  Abstract: The evolution of the probability density function for some parameters of interest, during the motion of a masonry arch under seismic actions, is determined by solving a first-order partial differential equation. The arch is represented as a one-dimensional structure and is examined in both the unreinforced and fibre-reinforced configurations. In both cases, the influence of the uncertainties of Young’s modulus and of the viscous damping coefficient on some displacements and on the amplitude of the cracked regions is determined. Among other things, the results show the potentialities of the method for investigating the effectiveness of FRP-retrofitting to improve the arches’ seismic performance.
  Keywords: masonry; arches; data sharing; dynamics; seismic; mechanical parameters uncertainties; evolution of probability density function.
  DOI: 10.1504/IJMRI.2023.10055672
   
  
• Masonry arches simulations using cohesion parameter as code enrichment for limit analysis approach  
  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  
  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  
  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  
  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  
  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  
  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  
  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  
  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  
  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  
  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
   
  
• Experimental investigation of the horizontal load orientation on masonry corner failure  
  by Carla Colombo, Nathanaël Savalle, Marco Francesco Funari, Georgios Vlachakis, Anastasios I. Giouvanidis, Shaghayegh Karimzadeh, Paulo B. Lourenço 
  Abstract: Field earthquake reconnaissance has revealed that masonry corner failure is one of the most common failure mechanisms. In literature, few studies have focused on the experimental investigation of such a mechanism, and they were usually performed considering the seismic action passing from the corner bisector. The present study conducts an experimental campaign on masonry corners and investigates how the orientation of the seismic action affects both the seismic capacity and the collapse mechanism. The experimental campaign involves two masonry corner configurations with different wall aspect ratios. Both configurations are made of a single-leaf dry-joint specimen, built with calcium silicate blocks. Results demonstrate how the orientation of the pseudo-static load simulated by means of a tilting table affects the structural capacity.
  Keywords: tilting test; flexural failure; rocking-sliding failure; dry-joint; interface stiffness; failure mechanisms; masonry.
  DOI: 10.1504/IJMRI.2023.10054545
   
  
• Consolidation of historic buildings damaged by settlements with composite materials  
  by Mihai Fofiu, Marius Mosoarca, Gigi Olariu, Marius Palade 
  Abstract: The current study presents the vulnerability assessment of two listed historical buildings, namely the episcopal palace Sibiu and the church called `Buna vestire si SF. Ioan’ from Golesti. A thorough investigation was carried out to identify existing cracks and damage to the buildings. A detailed analysis of the structure for both gravitational and seismic loads is presented, and the buildings are placed in a seismic risk class according to the Romanian code. After the analysis, appropriate retrofit measures were proposed to increase the load bearing capacity and improve the behavior. A special situation arises for these buildings due to the differentiated settlements the building is separated into distinct sections between which there is no longer a transfer of forces. In order to restore spatial cooperation between these sections of the same building, composite materials are used that ensure the transfer of forces between the load-bearing elements of the building and reduce the out-of-plane yielding mechanisms of the walls.
  Keywords: retrofitting; preservation; masonry buildings; rehabilitation; steel mesh; foundation stabilisation.
  DOI: 10.1504/IJMRI.2023.10057244