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Present concerns for sustainable development have led to a revival of traditional building practices using natural or recycled resources. There is a perception that buildings constructed from such materials are environmentally benign. This perception is questionable, as often no evaluation is undertaken to assess the associated environmental impacts. Rammed earth is one such construction technology that has seen renewed interest in recent years. The energy required to manufacture materials (i.e. embodied energy) is a significant component of the life cycle energy associated with buildings. This paper assesses the embodied energy of rammed earth construction relative to brick veneer and cavity brick construction. Rammed earth was found to have significantly less embodied energy than cavity brick construction (to which it is closer in thermal performance), but was approximately equivalent to brick veneer construction. Topics of further research identified include thermal performance and strategies for reducing the embodied energy of cement used for earth stabilisation.

Although the use of diverse types of bricks as the primary construction materials has been considered for many years, vernacular earthen materials are also widely used for construction with low potential environmental impacts in developing countries. In this study, the life cycle of two types of building materials for wall building is investigated.

For this purpose, life cycle carbon emissions (LCCO₂) are compared and embodied energy calculation for rammed earth and fired clay bricks as two construction materials. The complete construction chain using rammed earth, as a modern norm, and fired clay bricks, as the most common construction materials in buildings, is investigated in this research.

Studies on the constructions in Kashan city in the north of Isfahan province, Iran, as a case study, showed that replacing the fired bricks with rammed earth would reduce the CO₂ emissions up to 1,245 kg/ton and 4,646 MJ/ton (i.e. more than 95%) of the embodied energy. It also shows that the choice of building materials should be important for building practitioners to consider the environmental impact.

This paper provide life cycle assessment of building materials. The findings of this study help builders and owner to choose sustainable building materials.

The aims of the study are to analyze the features of a socially self‐contained society; to analyze the features of an environmentally sustainable society; and to generate a discussion on an indigenous approach towards the sustainable design of communities, particularly through the study of the round village for its unique form and performance in terms of sustainable construction.

Researchers from an international group undertook a field study of a number of specimen round and square shape Hakka villages in December 2004. They discussed their preliminary findings with local academics regarding significant attributes for sustainable design principles, and summarized lessons by means of spatial and construction studies that inform contemporary urban designers' knowledge and practice of sustainability through indigenous architecture.

Through reinterpretation of Feng‐shui theory, various observations made were easily and naturally correlated to basic laws of sustainability. The biggest message that comes from Fujian round architecture is that a genuine practitioner of environmental and social sustainability relies on a simplicity of approach – a respect for nature.

The study is confined primarily to observations by a team of architects and engineers.

Field study of vernacular architecture provides useful information and first‐hand data for researchers on rammed earth structures.

The study of rammed earth structures in remote areas of China, in both coastal and earthquake active zones, offers fresh insight into the integrity and ingenuity of early settlers in sustainable construction. The research provides preliminary findings regarding environmental and construction practice in age‐old Hakka round houses.

Construction works, which contributed to the built environment of the primitive, slave and feudal societies in ancient China, constitute an important component of Chinese history. This paper discusses the nest and cave dwellings as well as the tools used in the primitive society (before 2100 BC) of China. Construction works in the Slave Society (2100‐500 BC) encompassed the construction of city walls as well as wood and earth structures, covering roofs, wall and floor facing, and drainage facilities. The invention of new building materials and construction tools as well as standardization in working procedures and material consumption are discussed in “Feudal society” (221 BC‐AD 1840). The paper suggests that the more than 5,000 years of rich history of construction works in China should not be ignored.

This research aims to highlight the values, principles and recommendations for conservation in order to establish valid strategies for the conservation of earthen built heritage. This is done following a methodology which uses indirect (bibliography) and direct (case study) sources systematically analysed from different perspectives: the values of Earth as a material and of architectural and vernacular heritage; the heritage conservation principles found in international documents; and the analysis of over 3,000 case studies from which good practices in earthen architecture conservation are extracted.

Earthen built architectural heritage is found widely in all parts of the world, in archaeological sites and monumental and vernacular architecture, which research centres and researchers are increasingly studying and cataloguing. However, despite its richness and historic and cultural values, as well as its many merits in environmental sustainability, sociocultural and socio-economic terms, the value of this heritage has not been fully recognized in fields with major repercussions in conservation.

Finally, these data are cross-referenced to establish the broadest possible strategies to guarantee all aspects to be taken into account in the conservation of earthen built architectural heritage.

The text provides an overview of the different methodologies in order to extract specific strategies applicable to the conservation of this heritage, both locally and globally.

This study aims to investigate the optimum proportion of coconut fibre and cement suitable for rammed earth wall construction. Coconut fibres and cement can be easily incorporated into the soil mixture which adds strength and durability to the wall. This paper highlights the salient observations from a systematic investigation on the effect of coconut fibre on the performance of stabilized rammed earth blocks.

Stabilization of soil was done by adding Ordinary Portland Cement (2.5, 5.0, 7.5 and 10.0 per cent by weight of soil), whereas coconut fibre in length about 15 mm was added (0.2, 0.4, 0.6, 0.8 and 1.0 per cent by weight of soil) as reinforcement. Thirty types of mixes were created by adding different proportions of cement and fibre to locally available soil and compacting the mix at constant compaction energy in three layers with Proctor rammer.

Samples were tested for compressive strength and tensile strength, and failure patterns were analysed. The use of cement and fibre increases ultimate strengths significantly up to an optimum limit of 0.8 per cent fibre content, provides a secondary benefit of keeping material bound together after failure and increases residual strength. Benefits of fibre reinforcement includes both improved ductility in comparison with raw blocks and inhibition of crack propagation after its initial formation.

After analysing the results, it is recommended to use 0.8 per cent fibre and 5-10 per cent cement by weight of soil to achieve considerable strength. This research may add a value in the areas of green and sustainable housing, waste utilization, etc.

Heavy rainfall is one of the main causes of the degradation of historic rammed Earth architecture. For this reason, ensuring the conservation thereof entails understanding the factors involved in these risk situations. The purpose of this study is to research three past events in which rainfall caused damage and collapse to historic rammed Earth fortifications in Andalusia in order to analyse whether it is possible to prevent similar situations from occurring in the future.

The three case studies analysed are located in the south of Spain and occurred between 2017 and 2021. The hazard presented by rainfall within this context has been obtained from Art-Risk 3.0 (Registration No. 201999906530090). The vulnerability of the structures has been assessed with the Art-Risk 1 model. To characterise the strength, duration, and intensity of precipitation events, a workflow for the statistical use of GPM and GSMaP satellite resources has been designed, validated, and tested. The strength of the winds has been evaluated from data from ground-based weather stations.

GSMaP precipitation data is very similar to data from ground-based weather stations. Regarding the three risk events analysed, although they occurred in areas with a torrential rainfall hazard, the damage was caused by non-intense rainfall that did not exceed 5 mm/hour. The continuation of the rainfall for several days and the poor state of conservation of the walls seem to be the factors that triggered the collapses that fundamentally affected the restoration mortars.

A workflow applied to vulnerability and hazard analysis is presented, which validates the large-scale use of satellite images for past and present monitoring of heritage structure risk situations due to rain.

Salt weathering is one of the most common agents of decay of Central Asian earthen sites and is in function of water evaporation from the wall surface. Soon after excavation the earthen walls and the stupa of the Buddhist temple of Ajina Tepa (seventh-eighth century AD) started to deteriorate due lack of protection and surface erosion. The most important issue in the planning of conservation work was to understand such mechanisms and to decrease the effect of salt weathering on structural damage. The purpose of this paper is to discuss these issues.

Evaporation distribution and salts types were studied on selected walls. In addition, three-dimensional recording of the walls and the stupa was undertaken with digital photogrammetric methods.

It was clearly found that the intensity of salt weathering in the site is high and some salts such as halite (sodium chloride) are thought to originate from groundwater. On the basis of the results obtained, thick shelter coating with mud brick and mud render was designed and constructed as protective measure for the earthen walls.

Those walls that were most affected by salts weathering and erosion at the base (coving) became structurally less sound and eventually collapsed if not conserved.

The work is the first attempt in the design of a methodology for the selection of earthen repair materials and methods.

This study aims to present the uniqueness of the mountain oasis at the High Atlas (Morocco) and is part of a more extensive study about the landscape, the architecture and the tourist development in the Mgoun Valley. Several natural and anthropogenic factors, such as new environmental conditions and socio-cultural realities, are testing the balance of the system and its adaptive capacity. A sustainable use of water, a key element of the oasis and source of life in the region, and an optimal management of farmland will allow this culture to be perpetuated. The study of the values of this territory and its transformation vectors constitute a first step for valuing this ecosystem and being able to establish management and conservation policies.

The research is based on the fieldwork carried out over six campaigns, between September 2011 and January 2020, when interviews to the local population and graphic and photographic records of the Aït Mrau oasis were carried out. The work started from the literature review and the study of the origin of the settlement, analyzing the transformation processes, both in the cultivated plots and in the built habitat, where the urban evolution of the settlements and the characteristics of the architecture have been analyzed.

The study has revealed the existence of social, environmental and economic imbalances that affect the status of the oasis, the landscape and the architecture of the study area. The research has characterized the habitat and has identified those elements that must be preserved to guarantee the permanence of the heritage values in a way that the future development of the region was not conditioned.

The research delves into the study of a case that is paradigmatic in the context of the Moroccan High Atlas, since it shows the dynamics of transformation of a region directly affected by the climate change and by the abandonment of the traditional habitats.

Despite the dramatic increase in construction toward additive manufacturing, several challenges are faced using natural materials such as Earth and salt compared to the most market-useable materials in 3D printing as concrete which consumes high carbon emission.

Characterization and mechanical tests were conducted on 19 samples for three natural binders in dry and wet tests to mimic the additive manufacturing process in order to reach an efficient extrudable and printable mixture that fits the 3D printer.

Upon testing compressive strength against grain size, compaction, cohesion, shape, heat and water content, X-Salt was shown to record high compressive strength of 9.5 MPa. This is equivalent to old Karshif and fire bricks and surpasses both rammed Earth and new Karshif. Material flow analysis for X-Salt assessing energy usage showed that only 10% recycled waste was produced by the end of the life cycle compared to salt.

Findings are expected to upscale the use of 3D salt printing in on-site and off-site architectural applications.

Findings contribute to attempts to resolve challenges related to vernacular architecture using 3D salt printing with sufficient stability.

Benefits include recyclability and minimum environmental impact. Social aspects related to technology integration remain however for further research.

This paper expands the use of Karshif, a salt-based traditional building material in Egypt's desert by using X-Salt, a salt-base and natural adhesive, and investigating its printability by testing its mechanical properties to reach a cleaner and low-cost sustainable 3D printed mixture.