Search Results (75)

Rammed earth (RE), a traditional material aligned with circular economy (CE) principles, has been gaining renewed interest in contemporary construction due to its low environmental impact and compatibility with sustainable building strategies. Though not a modern invention, it is being reintroduced in response to the increasingly strict European Union (EU) regulations on carbon footprint, life cycle performance, and thermal efficiency. RE walls offer multiple benefits, including humidity regulation, thermal mass, plasticity, and structural strength. This study also draws attention to their often-overlooked ability to mitigate indoor overheating. To preserve these advantages while enhancing thermal performance, this study explores insulation strategies that maintain the vapor-permeable nature of RE walls. A parametric analysis using Delphin 6.1 software was conducted to simulate heat and moisture transfer in two main configurations: (a) a ventilated system insulated with mineral wool (MW), wood wool (WW), hemp shives (HS), and cellulose fiber (CF), protected by a jute mat wind barrier and finished with wooden cladding; (b) a closed system using MW and WW panels finished with lime plaster. In both cases, clay plaster was applied on the interior side. The results reveal distinct hygrothermal behavior among the insulation types and confirm the potential of natural, low-processed materials to support thermal comfort, moisture buffering, and the alignment with CE objectives in energy-efficient construction. Full article

In response to the growing demand for sustainable and performance-driven building design, this study proposes an integrated digital methodology that combines Building Information Modeling (BIM), parametric scripting, and multi-criteria decision-making (MCDM) to optimize external wall assemblies. The approach leverages Autodesk Revit and Dynamo to automate the parametrization of insulation thickness while ensuring compliance with regulatory thresholds for thermal transmittance and surface mass. Acoustic performance is estimated using ECHO software, and a Weighted Sum Model (WSM) is applied to evaluate and rank configurations based on four criteria: economic cost, Global Warming Potential (GWP), embodied energy, and acoustic insulation. A case study involving 24 wall assemblies—generated from eight base stratigraphies and three insulation materials—demonstrates the method’s ability to balance environmental impact, occupant comfort, and construction feasibility. The results indicate that natural and bio-based materials, such as rammed earth and cork, offer the best overall performance, while conventional systems remain competitive in terms of cost. The proposed workflow reduces design time, increases transparency, and supports informed decision-making during early design stages. This research contributes to the digitalization of sustainability assessment in architecture by promoting integrative, replicable, and regulation-aligned practices for low-impact building envelopes. Full article

The Gobi Wall is a 321 km-long structure made of earth, stone, and wood, located in the Gobi highland desert of Mongolia. It is the least understood section of the medieval wall system that extends from China into Mongolia. This study aims to determine its builders, purpose, and chronology. Additionally, we seek to better understand the ecological implications of constructing such an extensive system of walls, trenches, garrisons, and fortresses in the remote and harsh environment of the Gobi Desert. Our field expedition combined remote sensing, pedestrian surveys, and targeted excavations at key sites. The results indicate that the garrison walls and main long wall were primarily constructed using rammed earth, with wood and stone reinforcements. Excavations of garrisons uncovered evidence of long-term occupation, including artifacts spanning from 2nd c. BCE to 19th c. CE. According to our findings, the main construction and usage phase of the wall and its associated structures occurred throughout the Xi Xia dynasty (1038–1227 CE), a period characterized by advanced frontier defense systems and significant geopolitical shifts. This study challenges the perception of such structures as being purely defensive, revealing the Gobi Wall’s multifunctional role as an imperial tool for demarcating boundaries, managing populations and resources, and consolidating territorial control. Furthermore, our spatial and ecological analysis demonstrates that the distribution of local resources, such as water and wood, was critical in determining the route of the wall and the placement of associated garrisons and forts. Other geographic factors, including the location of mountain passes and the spread of sand dunes, were strategically utilized to enhance the effectiveness of the wall system. The results of this study reshape our understanding of medieval Inner Asian imperial infrastructure and its lasting impact on geopolitical landscapes. By integrating historical and archeological evidence with geographical analysis of the locations of garrisons and fortifications, we underscore the Xi Xia kingdom’s strategic emphasis on regulating trade, securing transportation routes, and monitoring frontier movement. Full article

Rammed earth (RE), despite being an ancient method of construction, has smoothly integrated into contemporary civil engineering due to its compatibility with current sustainability requirements for housing structures. However, typical RE needs some improvements to fully realize its potential as both a structurally effective and environmentally friendly building technique. As a result, multiple bio-inspired enhancement methods have been suggested to substitute traditional cement or lime stabilizers. This review examines the various efforts made in the past decade to biologically stabilize natural soil for the construction of RE. It provides a brief overview of the different bio-based materials utilized in this area but primarily concentrates on their effects on the mechanical strength and water durability of RE structures. The review also addresses current obstacles that prevent the widespread industrial adoption of this valuable earth-building method and identifies potential directions for future research. Overall, the available literature on the mechanical performance and durability of bio-based rammed earth (BRE) shows encouraging outcomes. Nonetheless, various issues, such as the absence of thorough data on the discussed topics, issues related to the inherent properties of soil and biomaterials, and doubts regarding the reliability of durability evaluation methods, have been identified as factors that could lead to a lack of confidence among RE practitioners in adopting bio-based treatments. This study will provide a solid foundation for future researchers aiming to advance BRE technology, thus enhancing sustainability within the construction sector. Full article

Under intensifying global warming and extreme climate events, the climate adaptability of folk houses in Xinjiang’s arid regions faces critical challenges. However, existing studies predominantly focus on traditional folk houses under current climate conditions, neglecting modern material hybrids and long-term performance under future warming scenarios. This study develops a data-driven framework to assess and enhance building envelope performance across historical-to-future climate conditions (2007–2021 TMY data, 2024 observations, and 2050/2080 SSP3–7.0 projections) using the entropy-weighted TOPSIS method and NSGA-II algorithm. Analyzing rammed earth, brick–wood, and brick–concrete folk houses in Kashgar, Hotan, Kuqa, and Turpan, the optimization targets thermal discomfort hours (TDHs), heating energy consumption (HEC), and net present value (NPV). The results demonstrate optimized solutions achieve 30–60 year climate resilience, reducing HEC by 51.54–84.76% (43.02–125.78 kW·h/m²·a) compared to baseline buildings, TDH by 15–52.93% (301–1236 h) in arid Zone A and by 5.54–10.8% (208–352 h) in the extreme hot-arid Zone B (Turpan), and NPV values by CNY 31,000–85,000. Rammed earth constructions demonstrate superior performance in Zone A, while brick–concrete exhibits optimal extreme hot-arid adaptability, and brick–wood requires prioritized retrofitting. The findings advocate revising China’s design standards to address concurrent winter overcooling and summer overheating risks under future warming. This work establishes a climate-resilient optimization paradigm for arid-region folk houses, advancing energy efficiency and thermal comfort. Full article

This study examines the main earthen constructions—such as adobe, compressed earth blocks (CEBs), and rammed earth walls (REWs)—highlighting their potential to reduce the environmental impact compared to conventional materials. Through a systematic literature review (2013–2024) and a meta-analysis, the mechanical, thermal, and sustainability properties of these constructions are analyzed. Emphasis is placed on the use of additives, such as stabilizers and fibers from various industrial and agro-industrial by-products, as leading actors influencing the mechanical and environmental performance of earthen constructions (EnCs). Remarkable improvements in the compressive and flexural strength are found, especially in stabilized CEBs and REWs, where strengths of up to 24 MPa are reached in certain mixtures, comparable to conventional materials such as concrete. However, the impact of these admixtures on environmental aspects, as measured through metrics such as the global warming potential (GWP), remains poorly documented. This review also shows that numerical methods like finite element modeling (FEM) have been crucial to modeling and predicting the performance of these materials, contributing to the understanding of their dynamic and structural responses. The findings suggest that, although CEB is currently the most studied onshore technique, future challenges include the standardization of admixtures and regulation of sustainable practices globally. Full article

The colors of traditional dwellings are an extremely intuitive manifestation of regional culture and an important reference for guiding rural housing. This study takes the Gutian district as the research region and explores the internal influence mechanism of the “color perception–preference–supportive behavior” of the indigenous residents towards traditional dwellings, specifically rammed earth dwellings. After constructing a structural equation model, the results were as follows: (1) The color perception of the indigenous residents towards traditional dwellings has two dimensions: distinctiveness and rootedness. (2) The color perception of the indigenous residents towards traditional dwellings can significantly enhance their color preference, but the two dimensions of color perception have different effects on color preference. (3) Color perception has a direct impact on color supportive behavior, mainly reflected in the dimension of the perception of distinctiveness. On the other hand, the mediating role of color preference has a positive impact on color—supportive behavior, mainly reflected in the dimension of the perception of rootedness. This study constructs a positive—cycle model that goes from the strengthening of color perception to the promotion of color preference and finally to the enhancement of color supportive behavior. The aim is to deeply analyze the multiple values contained in the colors of traditional dwellings, which not only demonstrate regional characteristics but also closely meet the emotional needs of the indigenous residents and have broad application potential in rural housing and cultural inheritance significance. Full article

This study investigates the scale effects on the experimental shear strength of earthen walls, a critical parameter influencing the seismic performance of adobe and rammed-earth (RE) buildings. Recognized for their historical significance and sustainable construction practices, earthen structures require a comprehensive understanding of their mechanical behavior under shear loads to ensure effective design and preservation. This research compiles data from over 120 in-plane shear wall tests (adobe and RE), nearly 20 direct shear tests from the scientific and technical literature, and new cyclic direct shear tests performed on large cubic specimens (300 mm side length) made from the same material as a previously tested two-story RE wall. Based on the findings, this study recommends a minimum specimen cross-sectional area of 0.5 m² for reliable shear strength testing of earthen walls in structural laboratories. This recommendation aims to prevent the unconservative overestimation of shear strength commonly observed in smaller specimens, including direct shear tests. Furthermore, the Mohr–Coulomb failure criterion outlined in the AIS-610 Colombian standard is validated as a conservative lower bound for all compiled shear strength data. Cyclic direct shear tests on nine 300 mm cubic specimens produced a Mohr–Coulomb envelope with an apparent cohesion of 0.0715 MPa and a slope of 0.66, whereas the full-scale two-story wall (5.95 × 6.20 × 0.65 m) constructed with the same material exhibited a much lower cohesion of 0.0139 MPa and a slope of 0.26. The analysis reveals significant scale effects, as small-scale specimens consistently overestimate shear strength due to their inability to capture macro-structural behaviors such as compaction layer interactions, construction joint weaknesses, and stress redistributions. Based on the analysis of the compiled data, the novelty of this study lies in defining a strength reduction factor for direct shear tests (3.4–3.8 for rammed earth, ~3.0 for adobe) to align with full-scale wall behavior, as well as establishing a minimum specimen size (≥0.5 m²) for reliable in-plane shear testing of earthen walls, ensuring accurate structural assessments of shear strength. This study provides a first approach to the shear behavior of unstabilized earth. To expand its application, future research should explore how the scale of specimens with different stabilizers affects their shear strength. Full article

This study investigates the potential of graphene-based additives to improve the mechanical properties of compacted soil mixtures in rammed-earth construction, contributing to the development of environmentally friendly building materials. Two distinct soils were selected, combined with sand at optimized ratios, and treated with varying concentrations of a graphene liquid solution and a graphene-based paste (0.001, 0.005, 0.01, 0.05, and 0.1 wt.% relative to the soil-sand proportion). The effects of these additives were analyzed using the modified Proctor compaction and unconfined compressive strength (UCS) tests, focusing on parameters such as optimum water content (OWC), maximum dry density (MDD), maximum strength (q_u), and stiffness modulus (E). The results demonstrated that graphene’s influence on compaction behavior and mechanical performance depends strongly on the soil composition, with minimal variation between additive types. In finer soil mixtures, graphene disrupted particle packing, increased water demand, and reduced strength. In silt–sandy mixtures, graphene’s hydrophobicity and limited interaction with fines decreased water absorption and preserved density but likewise led to diminished strength. Conclusions from the experiments suggest a possible interaction between graphene, soil’s finer fraction, and potentially the swelling and non-swelling clay minerals, providing insights into the complex interplay between soil properties. Full article

This paper examines the potential for shielding against electromagnetic (EM) radiation in traditional buildings. The primary objective is to evaluate how effectively these buildings can reduce the intensity of the electric field from external sources, while also identifying the factors that influence this reduction, such as geometry, structure, and the characteristics of EM waves. Measurements were conducted on the transmission parameter S₂₁, which indicates how EM waves propagate through the walls of residential buildings constructed using traditional methods. The buildings analyzed were made from wood, rammed earth, raw bricks blended with straw (known in Croatian as ćerpič), and baked bricks, which served as the reference material. During the measurements, conditions such as the thickness, humidity, and temperature of both the walls and the surrounding environment were carefully controlled. The buildings represented traditional construction styles typical of Croatia and most of Central and Eastern Europe. The results indicate that structures made from rammed earth and raw bricks with added straw significantly decrease the transmission of EM wave energy compared to those made from wood and baked bricks. It is important to note that the walls of wood buildings were considerably thinner than those made from the other materials tested. Additionally, both the moisture content and thickness of the walls contributed significantly to reducing transmission parameters. These findings support the use of these traditional materials for constructing environmentally friendly buildings, while also suggesting the need for further architectural design and testing. Since this research does not cover all types of traditionally constructed buildings—such as stone houses, wicker structures, and dugouts—future studies will aim to expand this investigation to include a broader variety of traditional building styles. Full article

This article documents the rammed earth construction practices undertaken at the “Tiles Hill–Xiangshan Campus Reception Centre” project. Traditional rammed earth craftsmanship is a sustainable construction method, with its core rooted in the precise material ratios and building techniques. This project aimed to explore the revival of this nearly forgotten vernacular construction method by integrating modern building technologies, all while adhering to the principle of avoiding any stabilizer additives. The project utilized a total of 2200 cubic meters of rammed earth to construct 16 walls, predominantly oriented north-south, with heights ranging from 3.6 m to 9.6 m and a thickness of 0.6 m. Before the formal commencement of the project, the team conducted experiments in the laboratory, constructing test walls to determine the optimal template fabrication and installation system compatible with modern rammed earth techniques. During the construction process, the team refined the rammed earth techniques, addressing challenges such as wall tilting, horizontal cracking caused by material settlement, and the flexible connection between the earthen walls and the primary structural framework through rational structural node design. The walls also passed compressive strength tests. Furthermore, advancements in the construction process allowed for the recycling and reuse of excavated soil. The article emphasizes that the sustainability of rammed earth techniques extends beyond material reuse to encompass the material’s inherent environmental friendliness and nondestructive nature. It argues that, provided there is a thorough understanding of the material properties of soil and reasonable structural and node design, coupled with the addition of necessary structural measures, it is entirely feasible to achieve ecological sustainability in rammed earth construction without the use of stabilizing additives. Full article

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. Full article

Industrial hemp, as a natural plant fiber, has received increased research attention recently. Potassium fertilization is one of the most important fertilizers for plant stem thickness, but how the formulation of K fertilizer influences stem morphology and stem tensile strength remains unclear. This study aims to examine the influence of K fertilizer sources on industrial hemp stem properties, with a specific focus on the fibers, to evaluate their potential applications as reinforcement material for stabilizing rammed earth in sustainable construction. A field experiment was set up with different K fertilizer types applied as pre-sowing fertilizer in the following doses: K₀—control, K₁—100 kg ha⁻¹ KCl, and K₂—100 kg ha⁻¹ K₂SO₄. Different K fertilizations did not have significant influence on stem height, which was on average 71.2 cm, nor on stem diameter, which was on average 3.4 mm. Regarding the macronutrient content of the industrial hemp stem (N, P, and K), K fertilization treatment significantly influenced (p < 0.05) their accumulation. The N, P, and K content in the stem within fertilization treatment averaged 0.78, 0.72, and 1.26%, respectively. The average content of cellulose, hemicellulose, and lignin was not significantly different in relation to K fertilization treatments. In the stem, dry weight cellulose content varied from 57.8% (K₀) to 59.0% (K₁), hemicellulose from 11.0% (K₂) to 11.6% (K₀ and K₁), and lignin from 10.2% (K₂) to 10.5% (K₀). The tensile strength and Young’s modulus of the industrial hemp stem were non-homogenous within K fertilization treatments. The highest tensile strength (388.52 MPa) and Young’s modulus (32.09 GPa) were on K₁ treatment. The lowest industrial hemp stem tensile strength was determined at K₂ treatment (95.16 MPa), whereas stems in the control treatment had the lowest Young’s modulus (21.09 GPa). In the mixtures of hemp fibers with rammed earth, the higher compressive strength was determined on cubic samples than on cylindrical samples. This study contributes to the industrial hemp K fertilization of the newer genotypes, but there has been a lack of research in recent times. Since industrial hemp has great potential in various industry branches, this study also contributes to using fiber extracted from the stem in eco-friendly and renewable forms in mixtures with rammed earth. Full article

Tulou, Tubao, and Zhailu all belong to the same vernacular architectural defensive rammed earth dwellings in Fujian; however, because of the similarity of their earthen defensive functions and fortress architectural systems, they are easily confused by scholars and there is still a gap in distinguishing the in-depth differences between the three. For the first time, this article develops a proper architectural typology with a comparative analysis of five aspects (origin and prototype, plan and type, building function and settlement typology, structure type and construction technology, and ethical concept and settlement model) to distinguish their architectural features. We find that they have different architectural prototypes and plan types. Tubao is a defensive dwelling with a residential function, Tulou is a defensive dwelling with a residential function, and Zhailu is a dwelling that combines living and defense. They have six different structural types. Although Tulou has the simplest structure and the thinnest rammed earth wall, its construction technology is the best. Tubao and Zhailu have more clearly defined architectural levels than Tulou, and Tubao’s hierarchy is the most significant. Therefore, we prove that despite their similarities, they are different types of buildings. This study helps to provide a methodological guide for identifying other, similar buildings and serves as a manual for the restoration and sustainable development of defensive rammed earth dwelling. Full article

In this investigation, the Taguchi method was employed to optimize a mix based on four natural by-products for rammed earth construction. Two separate studies were conducted to enhance the dry density and the Unconfined Compressive Strength (UCS). The four materials were assessed across four different levels, with moisture content also factored in as a parameter within a statistical analysis of 16 combinations. The Taguchi method predicted the combinations in which the Particle Size Distribution optimized the dry density and UCS as well as their dry density and UCS values. From the results, Moisture Content was the parameter with the highest influence on the optimization as well as the dry density and the UCS. It was observed that there was a direct relationship between the bulk density of the different granulometric fractions and their influence on the mix’s dry density. The fines were the material constituents that showed the highest influence on the mix UCS. When using the Taguchi method in RE building, the factor that should be maximized should is the mechanical strength. Full article