Adobe Research Articles

Evaluation of Retrofitting Techniques for Historical Adobe Constructions Using a multi-criteria Decision Analysis: The Case Study of Chile

ABSTRACT The evaluation of retrofitting techniques against multiple (often conflicting) criteria requires an expert-driven approach with in-depth context-based knowledge. This research evaluates the expected performance of retrofitting techniques for historical adobe constructions by integrating literature-data and expert assessment. Consideration is given to performance-based criteria (structural behaviour, material compatibility), values around cultural built heritage (degree of intrusion, retreatability), and local constraints (cost-effectiveness). A multi-criteria decision analysis using MACBETH (Measuring Attractiveness by a Categorical-Based Evaluation TecHnique) is undertaken in this study in order to facilitate the selection process for retrofitting techniques within distinct damage scenarios. The MACBETH model is applied to three historical adobe buildings in Chile using a weighted criteria matrix, while a sensitivity analysis is conducted to determine the stability of interventions. The best-scoring options for each damage pattern are then compared with national guidelines and the current practice. Among the best-ranking solutions obtained from MACBETH models, the use of wooden corner keys makes it possible to effectively counteract flexural cracks or mid-height cracks, damage at intersections of perpendicular walls, corner-damage vertical cracks, and in-plane damage. Wooden tie beams are effective solutions for corner-damage vertical cracks. Geo-mesh also obtains a high score yet is limited by its cost and low reversibility.

Adobe bricks as zero-material-cost solar evaporators for water-scarce regions

Consistent access to clean water is amongst the most pressing of global crises, particularly in less developed and off-grid communities. We present a high-efficiency solar evaporation device perfectly suited to address this crisis. Composed solely of soil, the adobe brick is a material that is easy to fabricate, and whose raw constituents are widely available at no cost. Once prepared, these bricks exhibit superb water absorption properties, excellent solar absorption, and efficient photothermal conversion, all of which contribute to a pure water evaporation rate of 2.52 kg m−2 h−1 (77 % evaporation efficiency) and a salt water evaporation rate of 2.16 kg m−2 h−1 under an irradiance of one sun. Suitable pore sizes allow salt water to be converted to fresh water with only minimal salt buildup over 6 h and rapid rejection of particulates to the reservoir below. Variations in soil makeup and inclusion materials are characterized in detail, and evaporation rates are compared. This enables recommendations for the composition of an ideal adobe brick evaporator and important conclusions for the study of solar evaporation materials. While soil composition may be optimized for performance, the high evaporation rates of all samples indicate opportunities for adobe brick desalination across all biomes.

Appraising the Seismic Response of a Retrofitted Adobe Historic Structure, the Role of Modal Updating and Advanced Computations

The concepts of structural assessment and retrofit of historical constructions are of particular complexity and require advanced knowledge in material science, conservation techniques and structural analysis. In particular, adobe constructions, given their low mechanical properties and brittle failure modes, are in immense need of comprehensive assessment and retrofitting plans. The current work focuses on the adobe Church of Kuñotambo in Peru, having experienced long periods of deterioration and earthquake-related damage. Under the ongoing Seismic Retrofitting Project (SRP) of the Getty Conservation Institute (GCI), the structural assessment of the church initiated in 2015 confirmed the low lateral capacity of the building and the poor connectivity between the structural parts. Based on the existing cracks and damage, a strengthening scheme was optimized and validated. After the implementation of the retrofitting plan, the quality of its execution and efficiency were assessed in 2019 with a new in situ campaign, which included ambient vibration testing (AVT) and sonic testing. From the acquired field data, the FE model of the retrofitted church was optimized, by updating the stiffness properties of masonry and discontinuities. Moreover, nonlinear static analyses were performed on the updated model in all in-plan directions. Finally, a displacement-based performance assessment was undertaken, under different earthquake limit states, demonstrating the adequacy of the retrofitting.

Appropriate Technology and Design: A Solution for Sustainable and Affordable Housing Delivery in Major Cities of Ghana

Appropriate technology and design for housing delivery undoubtedly has abundant cost benefit and other advantages. However, the acceptance of its usage and application for sustainable and affordable housing delivery is rare. Appropriate technology supports and enhances good life without compromising the earth’s ecosystem and the prospects of later generations. It is energy efficient, environmentally sound, and it is been controlled by the local community with local available materials. Appropriate housing design on other hand, focuses on the engineering and architectural perspective of a structure that supports sustainable construction and development. The paper aimed at determining the extent to which appropriate technologies and designs are currently employed in addressing housing sustainability and affordability in Ghana. Questionnaire survey was used for the data collection. The study was conducted in Accra, Takoradi and Cape Coast of Ghana within the period of 5 Months. In total, 110 questionnaires were distributed among Building and Construction Professionals and Self- Built House Owners. Out of the number distributed, 56 were retrieved for analysis. Data was analyzed using descriptive statistics. The findings of the study established that, hydrafoam, adobe bricks technology, timber homes technology, and wattle and daub technology were considered the most used and acceptable appropriate technologies for sustainable and affordable housing delivering. The findings of the study also revealed that, the extent to which appropriate technologies and designs have been adopted in major cities in Ghana is low. This implies that less emphasis is placed on the use of appropriate technology and design in resolving sustainable and affordable housing issues in major cities. It is therefore, suggested that, government and stakeholders mainstream the use of appropriate designs and technologies for sustainable and affordable delivery. Consequently, stakeholders should help change the perception of Ghanaians towards the adoption of appropriate technologies and designs for sustainable and affordable housing delivery.

Myths and Realities of the Salt Lake Temple Foundation

Myths and Realities of the Salt Lake Temple Foundation

Thermal conductivity prediction and comfort in adobe housing in Tamaulipas

In Mexico, there are efforts to recover earth-based construction systems, mainly those that improve the comfort characteristics consisting of a thermal sensation different from that of the environment. One of the questions derives from the reason why, at high ambient temperatures, earth houses tend to have a much lower temperature inside while, at very low temperatures, indoor temperatures are higher. This paper analyzes a type of housing present in Tamaulipas, Mexico, characterized by adobe walls and palm roofs. From a specific solution of the transport equations considering the heat capacity of the material and the coefficient of thermal conductivity, it is shown that the heat transfer of a homogeneous material in housing is dominated by these two properties, which justifies the present architectural design and the paradigm of a better comfort of earthen dwellings concerning industrialized materials such as the concrete block, we also show the energy efficiency according to NOM-020-ENER-2011.

Domestic donkey (Equus asinus asinus) at Gonur Depe and its distribution in the Ancient East

The domestic donkey (Equus asinus asinus) is a hardy, versatile working animal. This species still plays an important role in the traditional economy of the peoples of Central Asia and adjacent regions. At the same time, very little is known about the ways in which this domestic species appeared in the region and the nature of its use in the early historical epochs. The morphological features of ancient donkeys are also poorly studied. It is as-sumed that donkeys appear in the Middle East in the 4th millennium BC. Zooarchaeological data shows that the ancient population of Turkmenistan did not breed the donkey until the Late Bronze Age. Equid bones found at Chalcolithic, Early and Middle Bronze Age sites belong to the onager (Equus hemionus). Donkey bones first ap-peared in the materials from the excavations of the sites of the Bactria-Margiana Archaeological Culture (BMAC). One of the most famous site of BMAC is Gonur Depe, the administrative and ceremonial center of ancient Margi-ana. It is located in the ancient delta of the Murghab River. Gonur Depe dates from 2500 till 1500 BC. The protourban center includes two main sites — North and South Gonur. During the excavation at Gonur, 142 indi-vidual bones and 9 complete skeletons of the domestic donkey were found. Perhaps the isolated donkey bones fell into the trash layers during the destruction of the ritual objects. No traces of purposeful slaughter of these animals and consumption of their meat were found. The donkey skeletons were found inside the human burials or in associated structures, although there are independent burials of these animals as well. So, for example, at the area 8, the donkey, surrounded by ceramic vessels was placed in a tomb made of adobe bricks. In the burials 3200 and 3900, the skeletons of donkeys were found alongside the skeletons of double-humped camels and re-mains of four-wheeled wagons. In total, 4 burials with carts were found at Gonur, where the skeletons of camels are always present, whereas only in two of them — the skeletons of donkeys. It is possible that the bulls and camels were main draft animals of the Gonur people, while the donkeys mainly played the role of a pack and rid-ing animals. The height at the withers of the Gonur donkeys, reconstructed on the basis of measurements of the complete skeletons, was 115–120 cms. These were animals of average size for their species.

Hydrothermal Evaluation of Vernacular Housing: Comparing Case Studies of Waste PET Bottles, Stone, and Adobe Houses

This work shows the humidity and thermal evaluation of different case studies of houses. The analyses focused on room prototypes and houses built in different regions of Querétaro, México. Three different climatic zones were included with the evaluations of houses and prototypes. The assessments of internal and external parameters in residential buildings are also shown. The internal parameter measurements were done with hydro-thermometers and thermography images. Six structures were evaluated, one of the conventional housing materials and five of alternative or vernacular materials. The predicted mean vote (PMV) and the predicted percentage dissatisfied (PPD) were determined using the average temperature and relative humidity values, and they were considered to be dynamic because they can change depending on many factors. The six dwelling insulating properties were associated with their construction materials, design, location, and other factors. The six houses have many differences, but considering their behavior in their location, the two floor porous stone house got the best results. On the contrary, the flagstone house with a gabled roof of galvanized sheets had a cold perception despite many advantageous elements, failing to provide comfort in such a cold location. Contrasting these with other adobe constructions, the analyzed one had low thermal insulation, which was explained by its characteristics. PET and adobe uninhabited prototypes had medium to cold perceptions. The PET prototype has excellent and adjustable insulations, both on temperature and RH, considering the passive illumination and ventilation of its glass bottle skylights.

BUILDING BLOCK FOR HOT AND DRY CLIMATE OF RAJASTHAN

The wall materials such as bricks and blocks play an important role in the building design. In the olden days, it has been practiced by the vernacular method of construction for making bricks by using natural building materials which provide a comfortable living environment to mankind. Many such buildings are standing for a long duration and still mounted as examples in front of us. But in the present scenario, the need for rapid infrastructure growth and lack of skilled labor to utilize those vernacular materials in modern construction has diminished. In this age of technology development, the peopledecided to reduce the energy consumption in their buildings by promoting the concept of construction of low energy buildings using energy-efficient materials especially in wall materials. In this paper, comprehensive review is made on the various walling materials used in the state of Rajasthan such as Jodhpur sandstone, Clay bricks, Adobe Bricks, Fly ash bricks and AAC blocks.

Prevalence of Chagas Disease and Associated Factors in an Endemic Area of Northeastern Argentina.

Chagas disease caused by Trypanosoma cruzi, remains one of the leading public health problems in Latin America. The number of infections in nonendemic countries continues to rise as a consequence of migratory flows. Updated information on prevalence, especially in treatable stages, together with vector eradication programs are key factors in an attempt to control the disease. We aim to estimate the prevalence of T. cruzi infection in an endemic area of Argentina and to describe epidemiological and clinical factors related to the disease. This is a cross-sectional study in an endemic rural area of Argentina. Our target population was people between 10 and 20 years of age, collecting demographic, clinical, and electrocardiographic data and seroprevalence against T. cruzi. We included 460 subjects; 76.7% did not have drinking water; 49.3% reported the presence of Triatoma infestans at home; 79.1% had pets or birds; 72.6% lived close to a chicken coop; 24.6% lived in adobe houses; 27.8% lived in overcrowded conditions. Seroprevalence was 9.33%. In the multivariate analysis, the presence of Triatoma infestans at home (OR 2.08, P = 0.03) had an association with seropositivity. No relevant findings indicating acute or chronic organ involvement were detected. We found no correlation of right bundle branch block (RBBB) and Chagas disease in our population. None of the infected patients were previously aware of their condition, highlighting the importance of active surveillance to detect infection in a potentially treatable stage, especially in areas with difficult access to health programs.

Kuzey Suriye’de İç Mülteciler İçin Konut Üretiminde Kerpiç Malzemenin Rolü

Many people are in ınternally displaced people status in many parts of the world due to various reasons. The traditional adobe house architectural style has begun to be revived in northern Syria by many ınternally displaced people and those seeking shelter. Adobe material was reused in housing production, both through individual efforts and institutions and organizations. Various problems are experienced in the unplanned or planned camp areas that meet the shelter needs of ınternally displaced people to a great extent. The fact that the people at the design and implementation stage do not have sufficient knowledge about traditional adobe architecture, ignoring location, climate, and topographic features, and lack of public services and infrastructure have shown that the projects are not fully successful. The study, it is aimed to develop a house community model that meets the sheltering needs of internal refugees and produces solutions for the problems. In this context, the return to traditional adobe houses in northern Syria was handled and the continuity of the use of adobe materials was evaluated. It has great importance that the adobe house communities planned for ınternally displaced people are designed in line with the needs of the people who will live and that they are accessible and sustainable.

THE CONTRIBUTION OF WOODEN RING BEAMS TO THE RESPONSE OF THE ADOBE STRUCTURES

Earthen structures made of adobe bricks are complex systems making the calculation of their behavior difficult, especially when they have to sustain lateral forces such as seismic. 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 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 implementation of wooden ring beams. The test building is located in Cyprus, in the South Eastern Mediterranean region which is a seismic area. The models were subjected to various earthquakes performing time history analyses for the calculation of pertinent displacements and stresses. The results show that the installation of the wooden ring beams vastly changes the response of the building not only in terms of the magnitude of the displacements and stresses but also their distribution pattern.

Elemental Comparison of Bones of Red Sokoto (Capra Hiracus) and West African Dwarf (Capra Aeagurus) Goats for Production of Glazes

Elemental characterization of glaze materials has not been of scholarly concern, especially in Nigeria where studies have also excluded animal by-products for glaze derivation and glaze modeling. This study therefore elementally examined ashes of bones of Capra hiracus (Red Sokoto Goats) and Capra aeagurus (West African Dwarf Goats) and produced glazes with them with a view to providing scientific modeling of the glazes. Raw bone samples of each animal were separately collected processed into ashes and analysed using particle induce X-ray emission (PIXE) and Rutherford Backscattering spectroscopic (RBS) techniques. Thirteen elements Magnesium, Aluminum, Silicon, Cholrine, Phosphorus, Potassium, Calcium, Titanium, Copper, Zinc, Lead and Iron (Mg, Al, Si, Cl, P, K, Ca, Ti, Cu, Zn, Pb and Fe) were determined and based on which the ashes of each sample with adobe clay, whiting, borax and soda ash were successfully modeled into five glaze batches, applied on bisque wares and fired up to 1150 0C in a down-draught kiln. Undiluted ash samples gave white and off-white colours. Their mixtures with other materials gave sienna and brown-ochre colours with opaque effect. In other words, the final glaze effects of the ashes were opaque. Visually, WAD combination was most successful, though with pocket of crazing, crawling and peeling off hosts. Conclusively, it is the hope of this article, that its finding will provoke further studies on comparative examination of animal by-products for glaze formulation, theorization and practical application.

THE CONTRIBUTION OF WOODEN RING BEAMS TO THE RESPONSE OF THE ADOBE STRUCTURES

Earthen structures made of adobe bricks are complex systems making the calculation of their behavior difficult, especially when they have to sustain lateral forces such as seismic. 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 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 implementation of wooden ring beams. The test building is located in Cyprus, in the South Eastern Mediterranean region which is a seismic area. The models were subjected to various earthquakes performing time history analyses for the calculation of pertinent displacements and stresses. The results show that the installation of the wooden ring beams vastly changes the response of the building not only in terms of the magnitude of the displacements and stresses but also their distribution pattern.

Structural and mechanical performance of adobe with the addition of high-density polyethylene fibres for the construction of low-rise buildings

Adobe bricks have been used in construction since ancient times, due to their low cost, good performance and the ease of assembly and elaboration of these elements in construction. However, the low ductility and resistance of adobe could harm the structural behaviour of buildings, especially taller buildings. The addition of additives, in the form of abundant high-density polyethylene (HDPE) fibres, could improve the mechanical properties from a seismic and structural point of view. These improved adobes could replace factory bricks, whose mechanical deficiencies are similar to adobe (stiffness and flexural strength), and they could reduce the high cost of buildings today. This work analyses and compares the performance and structural performance that these elements acquire in framed buildings, compared to traditional adobe, incorporating different percentages of high-density polyethylene fibres (HDPE) in low-rise buildings (of 2 and 4 storeys), which are very abundant in areas of high seismicity. For this, models of structural frames are analysed, adding adobe walls using the mechanical results carried out in a laboratory at the University of Talca (Chile). The addition of a small percentage (0.6% and 1.2%) of HDPE in the traditional adobe, improves the ductility and the structural performance of the frames.

Research on the building materials of adobe house in the Neolithic period at the Qingtai site, China

AbstractAs one of the earthwork building methods, the adobe masonry has a long history around the world. In 2015, the Zhengzhou Institute of Cultural Relics and Archaeology discovered the earliest adobe house in Prehistoric China at the Qingtai Site. In this work, physical properties, material composition, and microstructure of the adobe brick and other earth samples gathered in this adobe house were studied. The results showed that the density and surface hardness of the adobe brick reached 2.12 g/cm and 91 HA, which was second only to the rammed house floor sample. The adobe brick contained about 13.2% of plant fiber, and in its inorganic composition, the clay cement with particle size less than 0.075 mm accounted for 90%. The results of XRD analysis showed that the content of kaolinite in adobe brick was 2–5 times that of other samples. The structure analysis displayed that the adobe brick was much more compact, and its porosity was about 28.6%. These research results demonstrated that the adobe brick was formed under a certain pressure and its raw materials were different from those of other samples in this adobe house.

Withdrawal and Transformation of Rural Homesteads in Traditional Agricultural Areas of China Based on Supply-Demand Balance Analysis

Idle and abandoned rural homesteads not only waste land resources, they also affect the quality of life of farmers and occupy land that could be used for agricultural production and ecological space. Analysis of the supply–demand relationship of rural homesteads is an important prerequisite for the implementation of rural homestead withdrawal and transformation, which is important for improving rural residential quality and land-use efficiency, promoting sustainable development and the classified revitalization of rural areas. Based on high-resolution remote sensing images of typical villages in traditional agricultural areas, a participatory evaluation method was used to analyze the supply–demand balance of rural homesteads and to propose countermeasures for their withdrawal and transformation. The results showed that: 1) rural homesteads have gradually realized the separation of living space and production space, the living function has gradually been enhanced, the production function has gradually weakened, and the ecological aesthetic function has emerged. 2) Farmers’ demand for rural homesteads is driven by various factors, including social and economic development level, lifestyle and livelihood. 3) There are a large number of idle or abandoned rural homesteads in traditional agricultural areas, with great withdrawal potential. The difference between the supply and demand of rural homesteads in use is obvious. The supply of living space of adobe house and mud-brick houses is less than the demand for them, and there is mixed use of space. The supply of production space for brick houses is less than the demand; in general, the supply of buildings is greater than the demand. 4) For rural homesteads still in use, exit and transformation strategies should be formulated according to the relationship between supply and demand, construction quality, spatial independence, and the wishes of farmers. The withdrawal and transformation of rural homesteads based on the balance between supply and demand is in line with the reality of rural development and the Chinese government’s strategy of national rural revitalization.

A New Mixture Criterion for the Improvement of the Compressive Strength of Adobe Using Zeolite as Stabilizer

The use of zeolite as a stabilizer for adobe has proven to have the ability to improve its physical and chemical properties. This is shown in the positive results in terms of strength gain and water absorption resistance in adobe blocks. In this work, an investigation was carried out to evaluate the use of zeolite as adobe stabilizer. The adobes were made with two different types of soil with different content of zeolite (5, 10, 15, 20% by weight) maintaining the zeolite-lime ratio 1:1. The samples were tested on compressive strength and water absorption. The deterioration of the adobes was analyzed under conditions of extreme humidity. The results of this study revealed that adobe behavior is influenced by the synergistic relationship between soil, zeolite and lime, showing significant changes in compressive strength even under extreme humidity conditions. It was also observed that the chemical composition of the soil influenced the development of the pozzolanic reaction. The stabilization of adobes with 15% of zeolite showed the best mechanical behavior, before and after deterioration assay. Hence, zeolite promises to be a good alternative as a stabilizer in adobe construction systems.

The Salt Lake City Asylum and Hospital, 1870–1886: Mental Illness in Early Utah

The Salt Lake City Asylum and Hospital, 1870–1886: Mental Illness in Early Utah

Under one roof: Material changes and familial estrangement in Puno, Peru

Traditional, Indigenous houses in Puno, Peru, were built using adobe bricks, stone, and wood. Today, young Indigenous couples are building houses that utilize modern materials such as concrete, brick, and steel. In this paper, I analyze the effects that changing materialities of house construction practices have on the durability and breadth of kin-relationships in Puno . I argue that these changes are possible due to the kind of personhood that houses occupy within kin networks in the Puno and the Andes. Furthermore, I show how access to new materials allows younger families to build houses more quickly than their parents did, shortening the time to develop stronger kin relationships that were once afforded by building with traditional materials. These new materials affect the house's ability to make and maintain kinship in the future where the quality of kin relationships is directly influenced by the material qualia of the house.