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This study presents a comprehensive bibliometric analysis of the earthen architecture and construction scientific literature production at present, analysing the historical evolution, research patterns and trends and the investigation of the different existing earthen building technologies. Utilising the SCOPUS database, this study analysed 3804 documents published between 1968 and 2023, with an annual growth of 16.92% since the year 2001. Key findings include the identification of top authors, institutions and collaborative networks, the co-citation analysis and the main keyword analysis and classification into different clusters. Regarding the building technologies, the results indicate a prevalence of research on vernacular earthen building techniques, mainly rammed earth and adobe masonry. Nevertheless, a growing interest in innovative methods using earth-based materials can be spotted. The bibliometric analysis identifies the development of the academic interest and emphasises the importance of interdisciplinary collaboration and the need for international recognition of earthen buildings. Future research should continue to explore the environmental benefits of using earthen materials, the development of earthen building techniques and systems in modern industry and the preservation of the architectural heritage and vernacular knowledge of contemporary technology. [ABSTRACT FROM AUTHOR]

This study presents a comprehensive bibliometric analysis of the earthen architecture and construction scientific literature production at present, analysing the historical evolution, research patterns and trends and the investigation of the different existing earthen building technologies. Utilising the SCOPUS database, this study analysed 3804 documents published between 1968 and 2023, with an annual growth of 16.92% since the year 2001. Key findings include the identification of top authors, institutions and collaborative networks, the co-citation analysis and the main keyword analysis and classification into different clusters. Regarding the building technologies, the results indicate a prevalence of research on vernacular earthen building techniques, mainly rammed earth and adobe masonry. Nevertheless, a growing interest in innovative methods using earth-based materials can be spotted. The bibliometric analysis identifies the development of the academic interest and emphasises the importance of interdisciplinary collaboration and the need for international recognition of earthen buildings. Future research should continue to explore the environmental benefits of using earthen materials, the development of earthen building techniques and systems in modern industry and the preservation of the architectural heritage and vernacular knowledge of contemporary technology.

Earthen structures made of adobe bricks are complex systems that making the identification of their behavior difficult, especially when they have to sustain lateral forces such as seismic forces. This paper presents a numerical investigation for the assessment of the structural response of unreinforced adobe masonry structures and how the installation of wooden ring beams contributes to their overall resistance. In the framework of the numerical investigation, finite element models were created to simulate the response of an adobe building with and without the presence of wooden ring beams. The test building is located in Cyprus, in the South Eastern Mediterranean region which is a seismic area. The material properties used in this study were found in the literature and were based on experimental data for local materials. The models were subjected to earthquake loads, performing time history analyses for the calculation of pertinent displacements and stresses. The findings indicate that integrating wooden ring beams reduces the fundamental period by 6% and modifies the building’s seismic behavior. This modification is evident not just in the magnitude of the stresses but also in their distribution, leading to a stratified stress profile. Peak stresses are primarily concentrated around the ring beams.

Earthen structures made of adobe bricks are complex systems that making the identification of their behavior difficult, especially when they have to sustain lateral forces such as seismic forces. This paper presents a numerical investigation for the assessment of the structural response of unreinforced adobe masonry structures and how the installation of wooden ring beams contributes to their overall resistance. In the framework of the numerical investigation, finite element models were created to simulate the response of an adobe building with and without the presence of wooden ring beams. The test building is located in Cyprus, in the South Eastern Mediterranean region which is a seismic area. The material properties used in this study were found in the literature and were based on experimental data for local materials. The models were subjected to earthquake loads, performing time history analyses for the calculation of pertinent displacements and stresses. The findings indicate that integrating wooden ring beams reduces the fundamental period by 6% and modifies the building's seismic behavior. This modification is evident not just in the magnitude of the stresses but also in their distribution, leading to a stratified stress profile. Peak stresses are primarily concentrated around the ring beams. [ABSTRACT FROM AUTHOR]

This paper presents the details of experimental testing of soil, adobe masonry units, and assemblages for the first time in Pakistan. Adobe units were tested both in compression and bending. The compressive strength of adobe masonry was determined by experimentally testing masonry prisms and wallettes, whereas diagonal compression wallettes were tested for determining shear strength. Five and three specimens were used, respectively, for compression and shear strength testing, and an average of these was used as a representative of a particular mechanical property. A soil sample was tested for classification and particle size distribution, which showed that it contained 96% silt and clay contents, which were higher as compared to the soil used for adobe structures in other parts of the world. Both adobe units and soil mortar presented shrinkage cracks upon drying. The compressive strength of adobe units complied with the requirements of international codes despite very high silt and clay contents in the employed soil. The compressive strength of the prism was higher compared to the wallette. The elastic moduli of the adobe masonry prism and wallette were found to be 113 and 114 MPa, respectively. Although the adobe masonry shear strength was comparable to the shear strength reported in the existing literature, its modulus of rigidity was considerably small. The presented data in this paper are essential for improving the built environment in Pakistan. [ABSTRACT FROM AUTHOR]

This paper studied compression properties on adobe masonry reinforced with fiber composites. Matrixes mainly included epoxy resin, earthen matrix consolidated by waterborne polyurethane and combination of the two. Uniaxial compression tests were carried out on twelve adobe masonry. Three of them were left unreinforced, while the other ones were reinforced with Fiber Reinforced Polymer (FRP), Fiber Reinforced Earthen matrix (FREM) and Fiber Reinforced Polymer with Earthen matrix (FRP-EM) by double-side layout, which reproduced the reinforcement for existing earthen walls. The research investigated on compressive strength, failure mode, stress strain curve and ductility. The results showed that FRP achieved a high strength improvement (56.4%) while FREM had relative low increase in strength (20.6%) due to premature debonding failure. FRP-EM increased strength by 77.3%, close to the combination of FRP and FREM. Moreover, The local debonding of FRP-EM systems due to uneven deformation of the internal composition was different from almost overall debonding of FREM systems. FRP and FRP-EM prevented the formation and propagation of the cracks and FREM reduced the width of major cracks on substrates. In addition, based on the modified Kent and park model, a constitutive model on adobe masonry reinforced with fiber composites was proposed, providing a reliable theoretical reference for the study. [ABSTRACT FROM AUTHOR]

Earth building has always existed on all continents; it constitutes an integral part of the cultural heritage of mankind. The present study is particularly interested in the valorisation of adobe masonry. To do this, a series of adobe units (three types: a, b and c) and adobe masonry wallets (A, B, and C) were prepared manually and infilled with 1cm thick earth mortar. In order to study the mechanical behaviour of the wallets in the laboratory, we study the mechanical behaviour of adobes and earth mortar then we apply the uniaxial loading method on the wallets. Also we present a new analytical formula which gives the mechanical properties of wallets derived from those of bricks and mortar that were determined before they were assembled. The experimental study shows that the compressive strength of wallets is 33% lower than that of adobes, and the deformations are similar to those of bricks, but they are 6 to 8 times smaller than those of mortar. The experimental mechanical properties of wallets were compared with those determined analytically. It give us results similar to the experimental ones with a ratio EManal/ EMexp equal to 1.2.

In Structural Health Monitoring understanding the effect of the environment on the modal properties of structures is essential. In this study, we evaluate the influence of changes in ambient conditions on the natural frequencies of three real large-scale structures: A 9-story reinforced concrete (RC) building and two sixteenth century churches of adobe masonry. For these structures, both environmental parameters (ambient temperature and relative humidity) and modal parameters were continuously monitored for a combined period of 8-years (RC building) and 2-years (for each of the adobe churches) in order to assess the effect of daily and seasonal variations of environmental parameters on the modal response. The results of the seasonal comparison indicate a negative correlation between ambient temperature and natural frequencies for the concrete structure, while for adobe structures a positive correlation between humidity and natural frequencies was observed. For daily variations, an out-of-phase and lag response of natural frequencies to variations in the environment was observed. A change on the daily lag was observed depending on the time of the year. Both seasonal and daily comparisons show the existence of a strong seasonality in frequency variations, where the form of response of this to environmental effects is different depending on the season. The magnitude of the daily variability is smaller in comparison to the seasonal variations. Finally, it was determined that the variation in natural frequencies depends on several factors such as the predominant material of the structure (namely reinforced concrete and adobe), the type of environmental exposure (temperature or humidity), and the characteristics of the structure (dimension of main elements). [ABSTRACT FROM AUTHOR]

Adobe masonry is one of the oldest construction systems still in use today, Mexico has an enormous cultural heritage with traditional adobe houses being very representative of the rural communities and their culture. The 2017 Puebla Earthquake on September 19th struck the country causing the loss, destruction, and damage of historic buildings in several Mexican states, with the traditional earthen dwellings being the most vulnerable structures to these events. The fast abandonment of the local materials and techniques entails further research regarding the characterization of these construction systems, therefore, reconstruction efforts first require the recovery of the construction technique. After the seismic events, adobe samples of the remaining adobe structures of Jojutla de Juarez were collected. This population was one of the most affected in all the country, and, because of the major losses suffered, the study was conducted to determine the material properties of the dwellings’ adobe shards and natural quarry clays of the region. The characterization included destructive and non-destructive tests, mineralogical and granulometry analyses, and composition of the adobe samples of the buildings, as well as the aggregates. As a novelty, the compressive strength of the pieces was tested by two methods: the traditional compression strength test and the point-load test, in order to obtain the indicative values and the correlation equations between both tests. From the formal analysis and the laboratory, it was observed that the adobes from Jojutla presented different compositions which combined with the building malpractices and alterations to the traditional systems caused unpredictable behavior during the earthquake. The conduction of point-load tests in situ, as a part of a complete characterization methodology, could be an alternative to study the mechanical properties of patrimonial or damaged building samples before its disappearance.

Throughout the world, millions of people are at risk because they live in unreinforced earthen dwellings, which have consistently shown extremely poor structural behaviour during earthquakes. Every single earthquake occurring in these areas has caused unacceptable loss of life, injuries, and property damage. Earthquakes are recurrent and construction damage is cumulative. It is urgent, therefore, to devise low-cost, easy-to-implement seismic reinforcement systems and to make them available to the actual dwellers. A group of researchers at the Pontificia Universidad Católica del Perú has been working towards that goal, especially on improving the seismic capacity of one-storey adobe dwellings. They have proposed construction methodologies for a seismic reinforcement system consisting of a mesh of nylon ropes that confines all earthen walls. This reinforcement system would control the wall displacements and prevent the overturning of wall portions that may occur due to seismic shaking. To validate the effectiveness of the nylon rope mesh reinforcement on two-storey adobe dwellings, shaking table tests were conducted on unreinforced and half-scale reinforced adobe models, simulating the actions of slight, moderate and strong seismic ground shaking. These models were designed to include the main construction features of typical adobe dwellings in the Peruvian Andes. The results of the experimental tests showed that the rope mesh reinforcement system was able to preserve the structural stability of the tested reduced-scale adobe models under strong motions, thus preventing collapse. It is expected that the proposed reinforced system would also improve the seismic performance of one and two-storey adobe dwellings, reducing in this way their inherent high seismic risk. [ABSTRACT FROM AUTHOR]

In Portugal, a large number of vernacular earthen buildings present an advanced state of degradation. These buildings comprise historical, technological, architectonic, cultural and social recognized values and, therefore, efficient interventions are needed for their conservation. The knowledge of the properties that the materials used in their construction show nowadays is one of the bases to support future interventions. Unstabilized earthen samples were collected from the walls of six earthen buildings located in the region of Leiria, Portugal, built with rammed earth and/or adobe masonry. The samples were characterized by particle size distribution and through XRD, density, capillary absorption, drying, dry abrasion, compressive and tensile flexural strength. Mechanical results of rammed earth were lower than adobe's, contrary to what was commonly found in other studies, and capillary coefficients of adobe were comparable to lime-stabilized adobe from other regions. A surface protection by compatible renders, respectively, earthen-based and air lime-based, is strongly encouraged to extend the walls durability. Although based on a short sampling, this data gives initial support to future compatible, effective and reversible interventions in Leiria vernacular earthen buildings, contributing to the preservation of this earth-built heritage. [ABSTRACT FROM AUTHOR]

Masonry construction is one of the oldest building systems and practiced since the early stage of human civilization. Even though industrialized nations developed new building practices using steel and concrete materials, most developing countries still use unreinforced masonry buildings. Evidence from past events shows that masonry structures sometimes performed well and survived several earthquake events, particularly in the area where earthquake events struck regularly and enough to show how structures behave. However, an alteration from the traditional cultural building practice is seen due to the lack of proper scientific knowledge about such local construction cultures. Amongst traditional construction technics, one captured authorities' and scientists' attention as showing excellent properties: seismic bands that can be found in many parts of Nepal. After the 2015 Gorkha earthquake, reconstruction works started adopting the guidelines developed by DUDBC and National Building code that suggest using such seismic bands. The evidence of using such band dates to 2500 BCE, and qualitative studies of those applications have proven to enhance the performance in the masonry structure. However, the experiment's quantitative parameters using various materials are needed to carry out the parametrical analysis to optimize seismic band's use. To provide quantitative results, we have started with two specimens, one without a band and one with a timber seismic band, and incorporate the digital image correlation (DIC) technique to obtain the localized information. The quasi-static cyclic test is carried out for our specimens to compare the behavior concerning the energy dissipation, and the surface area of the crack formed during the loading cyclic. This work clearly shows the seismic band's advantage in limiting the crack propagation and improving masonry structure integrity.

Hotel El Comercio is a typical colonial era house in Peru. This category of buildings exhibits specific architectural details and construction techniques, including adobe walls and mixed timber-earth systems (quincha). This paper presents the seismic assessment of the building in its current condition, proposing adequate strategies for modeling this type of buildings through finite element models, which remains a true challenge in case of seismic loading. Different sets of nonlinear properties are adopted and sensitivity analyses, involving different mechanical characteristics and load conditions, are performed in order to understand how they affect the structural response. [ABSTRACT FROM AUTHOR]

This paper presents shake-table tests which were performed on two 1:3 reduce-scaled adobe masonry models confined with vertical and horizontal bands. The model AM1 consisted of bands (tie beam) at sill, lintel and eave levels, and lightly reinforced concrete (RC) columns at the corners. The model AM2 was similar to AM1 except that RC columns at the corners were not provided in this model. The models were subjected to sinusoidal base motions for studying their seismic performance. The lateral force-deformation capacity curves for both the models were developed and were bi-linearized to compute the response parameters including stiffness, strength, ductility and response modification factor (R). Seismic performance levels of both the models were defined and their seismic performance assessment was carried out to evaluate their suitability in different seismic zones. The use of vertical columns in the AM1 model considerably increased its lateral strength as compared to the AM2 model. Although R factor of 2.0 has been recommended for both the models, seismic performance of the AM1 model was found better in all seismic zones due to high lateral strength of this model. [ABSTRACT FROM AUTHOR]

Adobe has been used as an economic building material since ancient times and continues to be used today, particularly in developing countries. Due to its sustainability credentials, interest in adobe as an alternative to traditional fired masonry has gathered pace. In order to develop guidance on the design of new adobe structures and the strengthening of existing ones, a detailed understanding of the material's properties is required. Currently available studies on adobe material often concentrate on one particular property. Due to the differences in adobe makeup, correlation of the existing results can be problematic. To address this, a detailed experimental study using one consistent, reproducible and realistic adobe mix is presented here. The material behavior in compression (including strength gain with time), tension, and shear is studied. For the first time, the interface between the adobe units and mud mortar is investigated in direct tension and in shear, including the effects of coexisting compression. Crucially, parameters such as tensile and shear fracture energy, often excluded from existing experimental work, are evaluated. The data provided herein will enable development of accurate numerical and analytical models to describe adobe masonry structural behavior. [ABSTRACT FROM AUTHOR]

• Macro-mechanical finite element model for traditional adobe masonry. • Simulation of normal and diagonal compression tests on adobe masonry wallettes. • Accuracy and robustness assessment of the numerical model. • Good numerical-experimental agreement on global and local performance measures. • Sensitivity to compressive strength, tensile strength and Young's modulus. A huge fraction of the worldwide built heritage consists of adobe masonry (AM) structures, including cultural heritage sites protected by UNESCO and single countries. In Portugal, the Aveiro district is a region where approximately 40% of the building stock is composed of AM structures with high cultural, social and architectural value. This paper presents a macro-mechanical finite element (FE) model that was developed for future performance assessments of AM structures. Based on available experimental data on Aveiro's AM, the FE model was validated in two different boundary and loading conditions associated with normal and diagonal compression tests. A satisfactory numerical-experimental agreement was found in terms of load-displacement curves, crack patterns, local stresses and deformations. A sensitivity analysis evidenced that compressive and tensile strengths mostly influence the peak load capacity and post-peak softening behaviour of wallettes, whereas Young's modulus affects the pre-peak rising branch of load-displacement curves. [ABSTRACT FROM AUTHOR]

Adobe is one of the oldest and most widely used building materials in the World. In the region of Aveiro, Portugal, traditional adobe construction represents about one-third of the existing buildings, some of which are of great architectural and patrimonial value. There is, however, a significant deterioration of several of these buildings, which need to be refurbished. A major difficulty for those involved in the process of structural assessment is the almost absence of references to adobe masonry mechanical properties. In this context, it is important to carry out the mechanical characterization of adobe masonry. Therefore, compression and shear tests were performed on adobe specimens from Aveiro's region load-bearing adobe walls. Tests were carried out for two moisture contents (saturated and unsaturated) in order to analyze the influence of the frequent moisture conditions in the mechanical behaviour of the adobe masonries and their components. Experimental results allowed determining mechanical properties of adobe loadbearing walls, whose reference values can be used in their safety conditions assessment. It was also possible to formulate corrected equations of the Eurocode 6 for compressive and shear strength. [ABSTRACT FROM AUTHOR]

• Structural and environmental continuous monitoring of adobe masonry was carried out. • Internal hygrometric measurements was not influenced by external conditions. • Environmental seasonal and daily effects were isolated from the structural response. • Daily results show a delayed effect of the env. conditions in structural response. • Results indicate a clear inverse relationship of temperature and dynamic properties. Through long-term monitoring, modal parameters identified in-situ can provide important information about the safety state of civil buildings and infrastructures. Unfortunately, structures are subjected to changing environmental conditions that can mask variations in the dynamic properties caused by damage and, therefore, lead to an incorrect condition assessment. The quantification of the influence of environmental conditions on modal parameters is a crucial step to eliminate their interference in a safety evaluation. Under current state-of-the-art considerations, this step is still an open challenge because environmental variables are time-dependent non-uniform quantities that have different influences on structural systems depending on the predominant material. In this paper, the effects of ambient temperature and humidity on the dynamic properties of earthen constructions are investigated using laboratory tests. A dynamic monitoring system was successfully implemented on adobe walls of different thicknesses to examine the influence of seasonal and daily variations of temperature and humidity. Three 1:1 scale adobe masonry walls were built and exposed to ambient conditions for 240 days. Temperature and humidity variations on the exterior, as well as in the inner walls, were continuously recorded together with the dynamic behavior using ambient vibration. The results provide useful insights on the influence of thermohygrometric parameters on the dynamic properties of adobe systems. The seasonal results indicate unclear correlations of ambient parameters and environmental variables. On the other hand, at a daily scale, the results indicate the existence of a clear relationship between inner measurements and dynamic properties. Moreover, the results indicate the existence of a delayed effect of external ambient parameters in the dynamic behavior of earthen systems. [ABSTRACT FROM AUTHOR]

This paper presents the results of a numerical study using the finite element method to assess the effect of wall thickness and a moist region along the wall base on the out-of-plane lateral stability of adobe walls. The models consisted of cantilever unreinforced adobe walls with a thickness of 25 cm, 30 cm, and 40 cm. Numerical analyses were performed for four lengths (L) of the moist region and for dry walls. The moist region was modelled with material characteristics corresponding to partially saturated and nearly saturated adobe. The results showed the detrimental effect of moisture along the lower portion of the wall on the out-of-plane lateral strength. The out-of-plane lateral strength reduction ratio dropped significantly as L increased. A high slenderness ratio was found to be critical for cantilever adobe walls when L extended beyond half of the wall length. The results provided insights concerning the role of wall thickness in the stability against overturning.

Highlights • The impact response of lightweight adobe masonry is investigated. • Existing shock response results are complemented by strength and failure modeling. • A hydrocode model is validated against new ballistic test data. • The penetration of a hollow projectile is considered as an independent test case. • Earlier results for a specific grade of adobe are extended to a class of materials. Abstract We conduct a comprehensive experimental and numerical study of the impact response of lightweight adobe masonry with a density of 1.2 g/cm3. Based on two independent test cases, a simulation model for lightweight adobe is validated and applied. First, we investigate the impact of a spherical projectile on finite and semi-infinite targets. Then, the penetration behavior of a generic hollow projectile is studied. In each case, the data from the ballistic experiments is compared to the results of corresponding numerical simulations. The employed numerical model utilizes a p-α-equation of state, recently derived from planar plate impact experiments on the same lightweight adobe material [Sauer et al., Journal of Dynamic Behavior of Materials 4 (2018) 231–243]. Strength and failure modeling are based on a validated numerical description of another adobe material that has a density of 1.8 g/cm3. The simulation model for lightweight adobe is capable of simultaneously reproducing all experimental results in a quantitatively appropriate way. This reveals that, although the phenomenology and quantitative properties differ significantly, lightweight adobe (1.2 g/cm3) and adobe (1.8 g/cm3) can be described by the same approach. Hence, this work suggests that the utilized model is applicable for analyses of impact loading of the entire class of adobe materials. [ABSTRACT FROM AUTHOR]

This paper discusses the shaking table test results of three PP-band (Polypropylene band) retrofitted quarter scale one-story masonry house models with different roof conditions. Better connections between masonry wall and roof connection are one factor to improve the seismic safety of the masonry houses. Past studies show that PP-band retrofitting improves the integrity of structural components and prevent the collapse of masonry structures during an earthquake. Although the effect of masonry unit type, surface plastering, the pitch of the PP-band mesh, PP-band connectivity in mesh and tightness of the mesh attachment to walls were studied by experiment program, the effect of the roof and its diaphragm connectivity on PP-band retrofitted masonry structure is nonexistent. Therefore, an experimental program was designed and executed for an understanding the effect of the roof and its connection on the dynamic behavior of the PP-band retrofitted box-shaped masonry house models. Results reveal that the PP-band retrofitted models with proper roof diaphragm improves the seismic behavior with respect to lateral drift, shear resistance and ductility. [ABSTRACT FROM AUTHOR]

We investigate the penetration of tungsten-heavy-alloy projectiles into adobe targets. The analysis rests on two complementary parts. Firstly, experimental data comprising impact experiments with five different projectile variants against finite-thickness adobe targets is available. Although the data stems from earlier work, it is presented in full detail here for the first time. The general phenomenology is discussed mainly with respect to projectile failure and stability of the penetration in adobe. Secondly, a recently published hydrocode model for adobe under impact loading is applied without further modification for complementing the experimental results with additional time-resolved insight into the penetration mechanics. For the regime without projectile failure or significant plastic deformation, this hydrocode model is capable of reproducing the experimentally observed projectile-target interaction with good overall agreement between experiments and simulation. While the test data covers different penetration regimes from rigid-body motion to projectile failure, the numerical analysis is restricted to linear-elastic behavior of the impactors, in order to avoid any ambiguity due to the less established projectile material description. With the information from the hydrocode simulations, we are able to reveal the origin of the projectile-specific magnitude of instability in the penetration in adobe. The thereby achieved understanding of the motion of the differently shaped impactors within the formed cavity allows us to discuss possible explanations for the particular projectile failure observed in the experimental data. [ABSTRACT FROM AUTHOR]

This study investigates the use of clay-based grout injections for the repair of adobe masonry constructions. Relevant data from the literature is reviewed, whilst the effectiveness of a laboratory-prepared clay-based grout is assessed through an experimental program. A 1:2 scaled adobe model building, previously subjected to a series of lateral loading cycles resulting in significant cracking damage, was injected with the clay-based grout and re-tested. The mix design of the aforementioned grout was based on the use of the same soil composing the earth masonry materials, hence ensuring compatibility between repairing and original materials. Although the grouting repair did not significantly alter the observed damage pattern after re-testing, it generally succeeded in preventing failure propagation through the injected crack paths. Furthermore, the injection of clay-based grout proved to be a repair technique capable of partly restoring the initial stiffness and load-bearing capacity of adobe masonry. The high strength recovery ratios recorded under the tests using static monotonic horizontal loading are particularly encouraging. [ABSTRACT FROM AUTHOR]

In June 2006, the Chair of Structural Design at the Technical University of Dresden was commissioned by the Iranian cultural authority ICHHTO and the UNESCO to perform structural design services for the earthquake-resistant repair and rebuilding of the Sistani House in the historic citadel Arg-e-Bam in the south of Iran. The citadel was until its almost complete destruction by an earthquake on 26 Dezember 2003 the largest building of unburnt brick masonry in the world and is listed as a World heritage Site by UNESCO because of its cultural and historical significance. Surveying and documentation work, archaeological rubble clearance and the rebuilding of the Sistani House after its destruction by the earthquake have taken the team from the department to Bam at regular intervals since 2006. In the course of the work, it became apparent that research was needed in the field of the repair of earthquake-damaged unburnt brick masonry and into the improvement of the shear strength/earthquake resistance and the weather protection of unburnt brick masonry. The article is subdivided in Part 1, Introduction, test performance and assessment of results for additives to loam render [14] as well as Part 2, Assessment of the results for surface treatment to unburnt bricks and the climatic chamber tests. [ABSTRACT FROM AUTHOR]

• Structural failure analysis of monumental adobe brick pyramid under lateral ground acceleration. • Multiscale 2D nonlinear dynamic FE model introduced for assessing the contribution of internal adobe pier architecture. • Time-evolution of elastic strain and plastic dissipation energies resulting from concrete damaged plasticity material formulation used to quantitatively track structural failure. • Lateral capacity critically affected by the frictional coefficient that governs contact between adobe piers. This study contributes to the seismic structural failure analysis of the main pyramid of the archaeological complex Huaca de la Luna, Peru. Built with millions of adobe bricks by the Moche civilization (200–850C.E.), the monument is one of the largest adobe structures in the world. The monument shows signs of severe natural and anthropogenic damage due to its position along the Pacific Ring of Fire and extensive looting since Spanish colonial times. The pyramid was built as a succession of taller and larger platforms, each formed by erecting adjacent but disconnected vertical piers made of adobe masonry. A multiscale 2D nonlinear finite element (FE) model is introduced for assessing the contribution of this pier architecture to the structural response of the pyramid. The time-evolution of elastic strain and plastic dissipation energies is used to quantitatively track structural failure. The instant of structural collapse and attendant lateral capacity can be extracted from the point at which these energies match. Critical regions of a representative cross-section are modelled with individual piers represented by macroblocks and separated by frictional interfaces. A continuous description is adopted for the remaining part of the model. A nonlinear, two-dimensional (2D) plane strain analysis is conducted in Abaqus/CAE Explicit using concrete damaged plasticity and Mohr-Coulomb formulations for adobe construction and soft soil, respectively. A two-stage assessment procedure begins with a quasi-static analysis to predict the stress state due to gravitational load. A dynamic analysis follows to identify lateral capacity and failure mechanisms triggered by monotonically increasing ground acceleration. The development of local damage conditions up to structural collapse is visualized by the nucleation and propagation of maximum principal plastic strains throughout the model. A sensitivity analysis was conducted to evaluate the effect on lateral capacity of the contact friction coefficient between macroblocks and the number of macroblocks used to discretize the critical area. Introducing macroblocks to the model produces lateral capacities that are lower than analogous, purely-continuum models. These results are shown to be critically affected by the frictional coefficient that governs contact between the macroblocks. The results of this study offer critical insights on the consolidation strategy for the northwest corner of the pyramid and may find application to similarly-built historical earthen structures in northern Peru. [ABSTRACT FROM AUTHOR]

• A non-linear constitutive law for adobe masonry was proposed. • A total strain crack-based macro-modelling approach was performed and validated through numerical modelling and comparison with values available in literature. • An adobe building in central Portugal representative of the city of Aveiro's earthen heritage was investigated as case study. • Local and global verifications of the case study buildings were carried out. • The seismic behaviour of the building was evaluated considering both isolated and aggregate conditions through a multi-criteria approach based on displacement and acceleration capacities, drift levels and safety against in-plane and out-of-plane failures. Non-linear static analyses are amongst engineering community one of the most common analysis approaches for the seismic assessment of existing buildings, due to a good trade-off between information needed and results produced to assess structural safety. Pushover analyses, in fact, can provide hindsight onto structural behaviour well into the non-linear range, up unto conditions of collapse initiation and structural failure. Reliable information concerning the material's mechanical behaviour – especially in the non-linear range - is, however, required – something which is challenging for earth-based materials, such as adobe masonry, due to the acknowledged variation of their mechanical properties. In this paper, a non-linear constitutive law for adobe masonry, numerically calibrated using experimental results and defined within the widely used computer program SAP2000®, a Finite Element software package commonly used by practicing engineers for building design and structural verification, is proposed. A total strain crack-based macro-modelling approach was pursued, and mechanical properties were validated through numerical modelling and comparison with values available in literature. The proposed constitutive model, whose reliability was proven by good agreement with experimental data, is then used to evaluate the expected seismic performance of a real case study given by an adobe building in central Portugal, representative of the city of Aveiro's earthen heritage. Therefore, starting from this application, more hindsight over the structural behaviour of Portuguese adobe masonry buildings under failure conditions was provided, also showing the implemented model suitability for large scale structural analysis in the SAP2000® software. Sensitivity analyses are run in Finite Element environment and the structural behaviour considering different boundary conditions of the building, namely isolated and aggregate conditions, is assessed through a multi-criteria approach accounting for displacement and acceleration capacity, drift levels and safety against in-plane and out-of-plane failures. [ABSTRACT FROM AUTHOR]

Earth construction is one of the oldest and most widespread construction system. Around 30% of world population lives in earth buildings. About 50% of population in developing countries, including the majority of rural areas, and at least 20% of urban and marginal urban areas, lives in earth buildings. The main general objectives of this study are the behaviour characterisation of adobe and rammed earth constructions along with the research for the development of retrofitting and seismic performance enhancement solutions, considering the relevant earthen heritage built in Portugal. In fact, until the first half of the last century, earth was commonly adopted as a construction material in Portugal. Adobe was used in almost all types of construction in littoral centre, particularly in Aveiro region. The consolidation of the knowledge on this technique and on the mechanical behaviour of adobe masonry will play a fundamental role on the preservation of the earthen built heritage. In addition, it may contribute to the development of innovative earth construction solutions for new buildings, following current concerns but also respecting structural safety demands, which will allow accommodating the increasing interest on this type of building solutions. The mechanical properties of adobe units and mortars were studied and a series of tests for the characterization of the adobe masonry behaviour were carried out, in the Department of Civil Engineering of the University of Aveiro, namely: (i) bond strength and (ii) joint shear tests. Additionally, a full-scale adobe building model was subjected to monotonic and cyclic horizontal lateral loads until failure. The present paper present the main results and conclusions of the experimental campaign developed. [ABSTRACT FROM AUTHOR]

Adobe masonry is part of the vernacular architecture of Cyprus. Thus, it is possible to use this technology in a meaningful way on the island. On the other hand, although adobe architecture is more sustainable in comparison to other building technologies, the use of it is diminishing in North Cyprus. The application of Turkish building code in the north of the island has created complications in respect of the use of adobe masonry, because this building code demands that reinforced concrete vertical tie-beams are used together with adobe masonry. The use of reinforced concrete elements together with adobe masonry causes problems in relation to the climatic response of the building as well as causing other technical and aesthetic problems. This situation makes the design of adobe masonry complicated and various types of ethical problems also emerge. The objective of this article is to analyse the ethical problems which arise as a consequence of the restrictive character of the building code, by analysing two case studies and conducting an interview with an architect who was involved with the use of adobe masonry in North Cyprus. According to the results of this article there are ethical problems at various levels in the design of both case studies. These problems are connected to the responsibilities of architects in respect of the social benefit, material production, aesthetics and affordability of the architecture as well as presenting distrustful behaviour where the obligations of architects to their clients is concerned. [ABSTRACT FROM AUTHOR]

Although it has good compressive behavior, adobe masonry is classified as a quasi-brittle material mainly due to its relative low tensile strength and softening behavior after the peak tensile strength. The behavior, plus the high variability in the adobe mechanical properties, makes it difficult to evaluate the performance of entire adobe buildings. For such a purpose, the development of reliable and computationally efficient numerical approaches is required. This work shows a numerical methodology to calibrate the main mechanical parameters to be used in the numerical modeling of adobe samples following the finite element method (FEM) by using the Total-Strain Crack model. The present paper shows that this numerical model is able to represent the nonlinear behavior of the adobe masonry. The calibration process is based on preliminary experimental tests performed on masonry prisms (piles and wallets) subjected to axial compressive and diagonal compression loads, respectively. The main results show that it is possible to model adobe masonry in practice. A consistent reproduction of the cracking pattern from experimental tests is obtained. By using the calibrated properties, this work may be extended to evaluate the seismic vulnerability of complete adobe structures. • A total-strain crack model is calibrated based on experimental tests. • The model captures well the highly non-linear behavior of adobe masonry. • The tensile strength controls the end of the elastic behavior in the model. • The tensile fracture energy controls the nonlinear behavior in the model. [ABSTRACT FROM AUTHOR]