Chapter

Environmental Life Cycle Analysis of Earthen Building Materials

Authors:
To read the full-text of this research, you can request a copy directly from the authors.

No full-text available

Request Full-text Paper PDF

To read the full-text of this research,
you can request a copy directly from the authors.

... Other authors compare different earth-based assemblies. For example, Mateus et al. [35], compare CEB and RE in a Portuguese scenario. Ben-Alon et al. [20] compare LSC, RE, and CEB with conventional assemblies. ...
... Embodied carbon (kg CO2 eq/unit) per adopted unit, considering the construction technique and life cycle stages considering the SLR data available in [19,20,27,31,32,34,35,36,40,44,46,47,48,49,50,51]. ...
... For the m 2 wall unit for RE, the values for A1-A5 go from the Portuguese scenario presented by [35,40] around 20 kg CO2 eq/m 2 , and Meek et al. [51] values around 80 CO2 eq/m 2 for stabilized RE with lime and cement. ...
Article
Full-text available
In the past decade, there has been an increase in the environmental performance assessment in earth construction through the life cycle assessment (LCA) methodology. A Systematic Literature Review verified LCA methodology trends of five earth construction techniques from 2016 to April 2022, resulting in 27 studies. The results have been analyzed through qualitative thematic analysis, considering LCA methodology. Considering embodied carbon (GWP) and embodied energy , transportation and binder content were the main factors that influenced environmental performance. Hence, earth-based constructions exhibit better results in different impact categories than conventional materials. Environmental guidelines and technical features that were presented in the LCA studies are discussed for Adobe, Cob, Rammed Earth (RE), Compressed Earth Block (CEB), and Light Straw Clay (LSC). This study presents environmental benchmarks at the unit, wall, and building scales aiming to encourage LCA methodology applied to earth construction techniques and fostering the discussion of earth construction sustainability.
... Compared with earthen materials, the values are under 0.5 kgCO2-eq/kg found in the literature [9]. Considering the building emissions scenario, by comparing the production of 1kg of ceramic bricks (0.25 kgCO2-eq/kg) and CEBs (0.07 kgCO2-eq/kg) in a Portuguese scenario [33], both LPC and LPC+L reached GHG emission values similar to construction materials, not as low as expected for earth-based construction materials. However, this comparison does not take into consideration the quantity of the material to fulfill the same function [33]. ...
... Considering the building emissions scenario, by comparing the production of 1kg of ceramic bricks (0.25 kgCO2-eq/kg) and CEBs (0.07 kgCO2-eq/kg) in a Portuguese scenario [33], both LPC and LPC+L reached GHG emission values similar to construction materials, not as low as expected for earth-based construction materials. However, this comparison does not take into consideration the quantity of the material to fulfill the same function [33]. ...
Article
Full-text available
Adobes are earth bricks made without compression or firing in casts, usually using local soil. To improve adobe´s durability and mechanical behavior, the adobes allow the addition of various materials to stabilize them. This work compares the technical and GHG (greenhouse gas emissions) of adobes stabilized with potassium hydroxide, commercial lime Portland cement, and cement with hydrated lime, room-temperature cured. The adobe formulation was inspired by traditional mud adobes from the Aveiro region (Portugal), composed of silty clay loam local soil (80 wt.%), stabilized with wheat straw fibers (10 vol.%) and crushed oyster shells as filler, incorporating bio-based material. The adobe samples were assessed after 28 days of curing and after accelerated aging cycles. The mineralogy of the stabilized adobes after 28 days was determined through X-ray fluorescence (XRF) and X-ray diffraction (XRD) analysis. The attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) compared changes after aging cycles. Compressive strength and water erosion tests were performed to assess the stabilization and durability of the adobes. GHG emissions (kgCO2-eq.) of the mixes were provided through the life cycle assessment (LCA) methodology. The results indicate that the adequate type of stabilizer can change regarding the application of the adobes in the building. Lime and cement provided better compressive strength and durability, allowing a broader range of applications with higher GHG in comparison to KOH adobes, which presented restricted applications. This study contributes to encouraging the use of LCA along with durability assessment in earthen materials to promote sustainability in the construction sector.
... Currently, the available studies on the Life Cycle Assessment (LCA) of earthen construction focus on assessing the environmental impacts of specific components such as adobe bricks [10,11], rammed earth structures [12][13][14][15][16][17][18], earth plasters [19,20], COB walls [21,22], CEB [23], or Earthbag Buildings [24]. ...
... The lack of uniformity when considering the functional unit does not enable direct comparisons between different construction techniques. Functional units, such as 1 kg of material [10], 1 m 2 wall [20,21], or specific samples like a brick [13,15], are found in the literature. In order to compare those techniques, a common functional unit should be used. ...
Article
Full-text available
Growing environmental awareness has prompted a resurgence in traditional building techniques that rely on natural or recycled materials since many believe that structures made from these resources are ecologically friendly. Using Life Cycle Assessment (LCA) for construction materials offers valuable insights into the impacts produced during their production and construction processes. This study aims to assess the environmental impacts of two different constructions—an Earthbag Building (EB) and a conventional Sahrawi Cement Blocks Building (CBB). It also determines whether it is more environmentally beneficial to construct traditionally, utilizing local materials and aligning with the principles of the circular economy, which is one of the Sustainable Development Goals (SDGs) in Europe. This study specifically examines a cradle-to-gate LCA, using the software Simapro v. 9.4.0.1. Results show that in 21 out of the 22 impact categories analyzed, the CBB performs worse, in some cases presenting an impact of 70% higher than the EB. The highest impact is obtained for fine particulate matter formation and Global Warming related to Human Health categories, whilst impact categories related to water consumption and eutrophication obtained an impact of less than 0.001 for both constructions.
... It guarantees high indoor hygrothermal comfort and a high level of air quality [4]. Furthermore, the blocks are unfired, which means low embodied carbon and energy [5][6][7], and they are entirely recyclable at the end of the life cycle [5,6]. ...
... It guarantees high indoor hygrothermal comfort and a high level of air quality [4]. Furthermore, the blocks are unfired, which means low embodied carbon and energy [5][6][7], and they are entirely recyclable at the end of the life cycle [5,6]. ...
Article
Full-text available
The purpose of this study is to explore Artificial Neural Networks (ANNs) to predict the compressive and tensile strengths of natural fibre-reinforced Compressed Earth Blocks (CEBs). To this end, a database was created by collecting data from the available literature. Data relating to 332 specimens (Database 1) were used for the prediction of the compressive strength (ANN1), and, due to the lack of some information, those relating to 130 specimens (Database 2) were used for the prediction of the tensile strength (ANN2). The developed tools showed high accuracy, i.e., correlation coefficients (R-value) equal to 0.97 for ANN1 and 0.91 for ANN2. Such promising results prompt their applicability for the design and orientation of experimental campaigns and support numerical investigations.
... Compressed Earth Blocks (CEBs) are framed in this context since the release of carbon dioxide into the atmosphere is 80% less than fired bricks [11]. At the end of their life, CEBs can be easily recycled to produce new earthen products, or they can be disaggregated and returned to the natural environment with a negligible environmental impact [12], generating a potential virtuous closed-loop cycle. Additionally, CEBs do not require specialised labour or high energy consumption, and they can be made everywhere. ...
... It must be said that these latest data do not consider the energy required and the emissions caused by the transport of materials and the mixing process. On the contrary, studies focusing on CEBs' LCA assessment [12,95] report that (i) the transport of raw material from the extraction site to the production site and (ii) the consumption of electricity and fuel used during the screening processes, mixing and pressing represent the two major contributors in the evaluation of the environmental impact, considering the cradle-to-gate life cycle. Therefore, some substantial aspects still remain to be clarified. ...
Article
A Systematic Literature Review (SLR) on the effect of the optimisation of Compressed Earth Blocks (CEBs) using natural origin materials was made in this paper. The purpose of the study is to offer a clearer vision of recent scientific developments on the topic by addressing a number of specifically formulated research questions. To this end, 45 journal articles and conference proceedings were selected following some inclusion criteria, i.e., the raw material (soil), shape (block), compaction methods (mechanical or hydraulic press), preparation (unfired), additives (natural origin fibres, powders or ashes). Through a holistic approach, a discussion on the main physical, thermal, mechanical, and durability properties was conducted to find correlations and criticisms. Preliminary considerations are drawn on the sound insulation and fire resistance properties and on the economic performance and environmental impact of optimised CEBs, opening a brief discussion on some sus- tainability indicators. The research outcomes may encourage researchers to find new solutions to improve the proprieties of earth building materials to promote their broader use and more sustainable buildings. (50 days' free access @ https://authors.elsevier.com/a/1dujt3O1E1Msdf)
... Even Iran's national regulations of buildings, like Issue 19, mostly examine the operatinal phase of buildings whereas the pre-construction and construction phases are mainly neglected [13]. Nonetheless, as buildings become more energy efficient, the importance of embodied energy during the life cycle of a building is increasing [14]. This is due to the fact that, normally reducing the operational energy demands more material input, which consequently increases the embodied energy [15]. ...
... Optimization results of new scientific and technological approaches indicate that these materials can be considered again as design alternative because they are environmentally and economically sustainable [21,22]. While the selection of construction materials is the most challenging task for the design team in sustainable buildings, earthen materials do not need industrial processing, could be used immediately within the site, and could be reused without any especial treatments [14]. This approach could be appropriately followed in Iran, a developing country where different social, cultural, economic and environmental factors often favours alternative solutions [23,24]. ...
Article
Full-text available
The Iranian building sector is the second contributor in energy consumption and carbon emissions. While the conventional construction systems and industrial building material in this industry are exacerbating the situation, the use of traditional techniques and earthen sustainable materials are left out. This paper seeks to unravel the environmental benefits of using traditional techniques, and earthen materials in the context of Yazd city. To do this, embodied and the operational energy and carbon emissions are selected to be investigated. Using LCA methodology, embodied and operational energy and carbon emissions of a pilot passive building which is built by Traditional Techniques and Materials (TTM) is compared with a building constructed by conventional systems and materials (CSM). Based on the results, the embodied energy and carbon emissions of TTM is 2.86 GJ/m² and 220 kg CO2 eq/m² which shows 43% and 48% decrease compared to CSM, respectively. Also the operational energy and carbon emissions are 0.35 GJ/m² and 68.25 kg CO2 eq/m² which are 88% and 81% lower than those of CSM, respectively. The main conclusion of this study is that due to the short life span of buildings in Iran, the impact of embodied energy on the life cycle of both TTM and CSM is significant, Moreover, the embodied energy constitute a larger share in TTM overall life cycle energy (89.1%). By comparing TTM and CSM, it is also concluded that the traditional techniques and earthen materials could have a profound impact on the overall life cycle energy and carbon emissions.
... Renewed interest in this material; which can be explained firstly, the desire to carry out part of the program devoted to rural housing, then by the concern to adapt the legislation to the new international context perspective of sustainable development [3]. Using earth, it is possible to significantly reduce the total embodied energy of a building as well as the environmental impacts [4,5]. ...
... Earthen construction has a promising future and is absolutely compatible with sustainable development objectives. Beyond this, compressed earth blocks have low or neutral potential environmental impacts in a life cycle perspective [5]. Further studies are lanced by our laboratory, in order to consider other life cycle stages, such as the use stage and to analysis other aspects such as sustainability. ...
Article
Full-text available
Sustainable development and environmental challenges incite to valorize local materials such as agricultural waste. In this context, a new ecological compressed earth blocks (CEB S ) with addition of ground olive stone (GOS) was proposed. The GOS is added as partial clay replacement in different proportions. The main objective of this paper is to study the effect of GOS levels on the thermal properties and mechanical behavior of CEB. We proceeded to determining the optimal water content and equivalent wet density by compaction using a hydraulic press, at a pressure of 10 MPa. The maximum compressive strength is reached at 15% of the GOS. This percentage increases the mechanical properties by 19.66%, and decreases the thermal conductivity by 37.63%. These results are due to the optimal water responsible for the consolidation and compactness of the clay matrix. The substitution up to 30% of GOS shows a decrease of compressive strength and thermal conductivity by about 38.38% and 50.64% respectively. The decrease in dry density and thermal conductivity is related to the content of GOS, which is composed of organic and porous fibers. The GOS seems promising for improving the thermo-mechanical characteristics of CEB and which can also be used as reinforcement in CEB S .
... Compressed earth blocks (CEBs) are building blocks that are produced by compacting soil/earth in an electrical or hydraulic block-making machine, in which a environmentally friendly, as they do not require the burning of coal or other fuels in their production, unlike conventional fire-burnt clay bricks [3]. CEBs are also aligned with green building principles because they can be sourced on-site, and minimise transportation costs [6][7][8]. Additionally, the thermal mass of earth-based materials helps regulate indoor temperature, reducing reliance on energy-intensive heating and cooling systems [9][10][11]. ...
Article
Full-text available
The use of eggshells in building materials has gained interest due to its prospect of enhancing the mechanical properties of concrete and its role as an eco-friendly alternative to traditional materials. Combining waste crushed eggshells and lime in earth blocks has the potential to inform the development of affordable and eco-friendly housing solutions for low-income communities. This study, therefore, examined the mechanical and physical properties of compressed earth blocks (CEBs) stabilised with eggshells and lime. Experiments were conducted on 140 × 100 x 100 mm earth blocks stabilised with 10% constant lime and 0, 0.25, 0.5, 0.75, 1% eggshell contents. CEBs were tested for density, water absorption, tensile strength, compressive strength, erosion, chemical composition, and microstructural on 7, 14, 21, and 28 curing days. At 28 days of curing, the 1% eggshell and 10% lime-stabilised compressed earth blocks recorded compressive strength of 1.331 N/mm2 compared with the unstabilised compressed earth blocks' strength of 1.054 N/mm2, which represents a 21% increase in compressive strength, and the difference was found be statistically significant (p = 0.016). ABSTRACT The use of eggshells in building materials has gained interest due to its prospect of enhancing the mechanical properties of concrete and its role as an eco-friendly alternative to traditional materials. Combining waste crushed eggshells and lime in earth blocks has the potential to inform the development of affordable and eco-friendly housing solutions for low-income communities. This study, therefore, examined the mechanical and physical properties of compressed earth blocks (CEBs) stabilised with eggshells and lime. Experiments were conducted on 140 × 100 x 100 mm earth blocks stabilised with 10% constant lime and 0, 0.25, 0.5, 0.75, 1% eggshell contents. CEBs were tested for density, water absorption, tensile strength, compressive strength, erosion, chemical composition, and microstructural on 7, 14, 21, and 28 curing days. At 28 days of curing, the 1% eggshell and 10% lime-stabilised compressed earth blocks recorded compressive strength of 1.331 N/mm 2 compared with the unstabilised compressed earth blocks' strength of 1.054 N/mm 2 , which represents a 21% increase in compressive strength, and the difference was found be statistically significant (p = 0.016). At 28 days of curing, the 1% eggshell and 10% lime-stabilised compressed earth blocks' tensile strength was 0.173 N/mm 2 compared with the unstabilised compressed earth blocks' strength of 0.138 N/mm 2 , which represents a 20% tensile strength increase. The eggshell and lime-stabilised compressed earth blocks also exhibited reduced water absorption of 3.32% compared to unstabilised blocks of 4.62%. SEM analysis revealed the earth particle structure, lime particle crystal shape, crack distribution, and surface properties of the CEBs. EDS analyses further confirmed the presence of key elements like iron, titanium, calcium, silicon, aluminium, oxygen, and carbon in the CEBs. The study concludes that the presence of eggshells and lime in the earth matrix enhanced the properties of the compressed earth blocks. It is recommended that block manufacturers use 1% eggshell and 10% lime to enhance the properties of the compressed earth blocks as this blend provided optimum results.
... Compressed earth blocks (CEBs) are building blocks that are produced by compacting soil/earth in an electrical or hydraulic block-making machine, in which a environmentally friendly, as they do not require the burning of coal or other fuels in their production, unlike conventional fire-burnt clay bricks [3]. CEBs are also aligned with green building principles because they can be sourced on-site, and minimise transportation costs [6][7][8]. Additionally, the thermal mass of earth-based materials helps regulate indoor temperature, reducing reliance on energy-intensive heating and cooling systems [9][10][11]. ...
Article
Full-text available
The use of eggshells in building materials has gained interest due to its prospect of enhancing the mechanical properties of concrete and its role as an eco-friendly alternative to traditional materials. Combining waste crushed eggshells and lime in earth blocks has the potential to inform the development of affordable and eco-friendly housing solutions for low-income communities. This study, therefore, examined the mechanical and physical properties of compressed earth blocks (CEBs) stabilised with eggshells and lime. Experiments were conducted on 140 × 100 x 100 mm earth blocks stabilised with 10% constant lime and 0, 0.25, 0.5, 0.75, 1% eggshell contents. CEBs were tested for density, water absorption, tensile strength, compressive strength, erosion, chemical composition, and microstructural on 7, 14, 21, and 28 curing days. At 28 days of curing, the 1% eggshell and 10% lime-stabilised compressed earth blocks recorded compressive strength of 1.331 N/mm2 compared with the unstabilised compressed earth blocks’ strength of 1.054 N/mm2, which represents a 21% increase in compressive strength, and the difference was found be statistically significant (p = 0.016). Keywords: compressive strength, compressed earth blocks (CEBs), eggshell waste, lime, mechanical properties, tensile strength, water absorption, sustainability, stabilization, micros- tructural analysis.
... Natural earth-fiber materials in building construction have been a historic practice overlooked by the rapid processing and use of modern materials -a significant climate change contributor [7,11]. Life cycle assessment (LCA) models for building construction, which are analyses for measuring a building's environmental impact from its material production (cradle) to its transport on location (site) and end of use (grave), have been used to document natural materials as carbon-neutral alternatives compared to life-cycles of modern building materials such as Portland cement and steel production [7,[11][12][13]27]. Furthermore, the use of natural materials has proven mechanical and thermal properties yet is omitted in mainstream construction practices due its inaccurate perception of being low-tech [14][15][16]. ...
Article
Full-text available
Natural building materials are critical to the future of a decarbonized built environment. Involving low-carbon and readily available materials such as clay-richsoils and plant fibers in building processes employ a range of techniques, and hence, a range of environmental and visual features, from rammed earth to cob and light straw clay. However, despite their advantages, natural materials are not represented in mainstream construction, perceived mistakenly as poor in theirperformance, low-tech, and are missing representation in training for building professionals. This research develops a digital representations-study of naturalmaterial futures and their associated embodied carbon. It links, for the first time, computational play, and critical data with traditional recipes of designing with natural materials. A digital tool for sustainable engagement was developed by utilizing a geological database of locally available soil-based repositories. As an exploratory design tool, it was tested through 24 playtests for its mechanics, graphical user interface, and perception shifts among designers and researchers. The final outcome seeks to establish a digital foundation for a more comprehensive earthen materials knowledge tool and life-cycle assessment. As a final deliverable, this work aims to unveil the strength of simulative material representations in heightening the knowledge base of an overlooked, historic, and sustainable practice.
... At the end of their life cycle, CEBs can be reused, recycled [11], or possibly disaggregated and returned to the natural environment. These characteristics are critical for the assessment of the environmental performance of the product, positioning CEBs as promising candidates to contribute to the decarbonisation of the construction sector and the promotion of a circular economy in the building materials cycle [12]. ...
Article
Full-text available
Building materials are responsible for significant CO2 emissions and energy consumption, both during production and operational phases. Earth as a building material offers a valuable alternative to conventional materials, as it naturally provides high hygrothermal comfort and air quality even with passive conditioning systems. However, disadvantages related to high density, conductivity, and wall thickness prevent its effective inclusion in the mainstream. This research explores enhancing the thermophysical properties of compressed earth blocks (CEBs) by using locally sourced natural materials. The study is framed in the Portuguese context and the natural materials involved are wheat straw (WS) as a by-product of wheat harvesting, cork granules (CGs) from bottle caps, and ground olive stone (GOS) residues from olive oil production. Blocks were produced with different mixtures of these materials and the thermal response was examined in a hot box apparatus. Best results include a 20 and 26% reduction in thermal conductivity for mixtures with 5v.% CG and 10v.% GOS, respectively, and an associated reduction in bulk density of 3.8 and 5.4%. The proposed approach therefore proves to be effective in improving the key thermophysical characteristics of CEBs. The article includes a comparative analysis of the experimental data from this study with those from the literature. The study contributes to the growing knowledge of sustainable materials, providing insights for researchers and practitioners looking for innovative solutions for low-carbon and energy-efficient materials.
... Compared to an adobe house of a similar floor area, a reduction of around 100 tons/year of CO 2 emissions to the environment was found. Similar CO 2 emission reduction results were found by Mateus et al. [13] when investigating rammed earth and compressed earth blocks, indicating that earth is an environmentally friendly building medium compared to conventional construction materials. ...
Article
Full-text available
This work addresses the development of compressed earth blocks with high quality using stabilizers and reinforcements of industrial and agroindustrial by-products. A critique of the production of compressed earth blocks using new mixtures, compositions, and characteristics required for adequate performance according to different construction standards is included. Furthermore, the effect of adding stabilizers and reinforcements from industrial and agro-industrial by-products on strength, durability and thermal insulation is evaluated. Fibers improve tensile and crack resistance, while stabilizers enhance the cohesion of mixtures, originating new compounds with higher compressive strength and lower permeability. Finally, the main prediction tools for engineering design and application of compressed earth blocks in buildings are discussed. The main findings and research gaps identified provide a baseline for future research projects focused on the transition to a low-carbon future through the production of compressed earth blocks.
... The numerous advantages of raw earth as a building material are nowadays universally recognized [9][10][11] and cover diversified sectors: low energy consumption [12,13], excellent indoor air quality [14,15], hygrothermal comfort [16][17][18][19][20][21][22][23], lack of volatile organic compounds (VOCs) [15,24], recyclability [25] and reduction of CO 2 production [26]. Moreover, non-toxicity, local availability and the possibility of using soils from footing excavation with very low initial costs are also acknowledged in raw earth construction [27]. ...
Article
Full-text available
Raw earth has useful applications in contemporary buildings as a sustainable and circular construction material. The present study aims to assess the environmental performance of several earth-based wall systems with similar thermal performance, through a life cycle thinking approach. In particular, a life cycle assessment is developed for (a) unstabilized rammed earth (produced in situ), (b) compressed earth blocks (prefabricated in the factory), (c) stabilized rammed earth and (d) light earth, all combined with biobased (natural fibers, e.g., lime hemp, cork) and/or conventional materials for building insulation. Results show benefits in terms of avoided carbon emission, water footprint and embodied energy throughout the production chain and highlight limits and potential improvements. In addition, the CO2 offset by crops is also estimated based on carbon embedded in natural fibers. In particular, light earth wall systems are the most suitable to minimize environmental impacts, while massive constructive technologies (as unstabilized rammed earth) show a higher dynamic thermal performance for intended use in Mediterranean climates.
... Efforts are being made to encourage the construction of new houses for low-income families by using local building materials. Earthen buildings have been used for millennia and even today, approximately 35% of the world's population live and work in earthen houses [3,4]. Earth is an eco-friendly, low-cost, widely available building material that can help to promote living in comfort and decrease environmental issues. ...
Article
Full-text available
This study investigates the impact of incorporating Juncus fibers (JF) into compressed earth blocks (CEBs) stabilized with varying Portland cement contents, aiming to enhance local construction materials’ performance and reduce housing costs. CEB composites were produced with soil stabilized using different cement contents (4%, 8%, and 12% by weight) and JF reinforcement (0 to 0.2% by weight), compressed at 10 MPa with a hydraulic press. After 28 days of drying, the CEBs underwent diverse experimental characterizations to assess their physical, mechanical, thermal, and durability properties. The results revealed that incorporating JF led to a reduction in unit weight, ultrasonic pulse velocity (up to 36%), and dry compressive strength (approximately 17%). Higher fiber content correlated with increased water absorption and an increased capillarity coefficient. Thermal conductivity analysis indicated improved thermal performance, decreasing from 0.4350 W/m·K (12% cement without fibers) to 0.2465 W/m·K (4% cement with 0.2% JF). Despite the decrease in mechanical strength, CEBs with lower cement (4%) and higher fiber content (0.2%) demonstrated satisfactory durability (abrasion and erosion) and thermal insulation properties. This research suggests the potential of this material as a promising composite for the building materials industry. The findings contribute valuable insights into sustainable construction materials and have implications for cost-effective housing solutions.
... Authors also confirmed in their research that the mud home has higher thermal performance in allweather than a brick or CI Sheet house because the inside air temperature is less impacted by the outside temperature. So, it is supported by different studies that, vernacular materials offer lower embodied energy than those currently used in the building industry since they are locally accessible, need extremely low-intensive energy manufacturing processes, and do not need to be transported over larger distances (Khan & Kabir, n.d.) (Mateus et al., 2020). And the present study found consistent results with the previous studies. ...
Article
Full-text available
Concerns over climate change have driven the need for decarbonization of the building sector all over the world. It is proven that manufacturing building materials consumes a substantial amount of non-renewable energy and releases carbon emissions. For this reason, it has become an essential need for finding clean and energy-efficient alternative building materials. In Bangladesh, vernacular houses in rural areas are made of locally found materials like mud, bamboo, thatch, wood, and others and are always used in the construction of houses without any industrial processing, these dwellings are composed of materials with very little or no embodied energy (E.E). However, there has been a significant change in the construction of houses and the use of materials in rural Bangladesh in the last two decades. Concrete, brick, metal sheets, and many other industrial materials have taken possession of indigenous technology and bio-based materials. As a result, environmentally sustainable traditional houses have been transformed into energy-intensive houses. This research aims to study vernacular building materials in Bangladesh to identify their embodied energy, climatic performance, thermal conductivity, and durability for constructing low-carbon and less energy-consumed buildings. Based on several case studies, field surveys, and literature reviews the assessment has been conducted, showing that these materials are highly efficient in terms of embodied energy and can also ensure great thermal comfort. This study also evaluates the durability of these materials and depicts that by enhancing their durability, these materials can act as the best-performing building materials in all aspects.
... Nowadays, the building industry must tackle new issues; the scarcity of non-renewable resources and the reduction of materials' embodied energy are two of them [14,15]. Modern building techniques, especially reinforced cement concrete solutions, hardly respond to these issues, as cement production is responsible for an important part of global CO 2 emissions [16][17][18]. ...
Article
Full-text available
The use of quarry by-products can enable the commercialization of a clay building material (reconstituted earth) thanks to minimal valorized and perennial stocks of materials. This study shows that quarry by-products can be used to mix design a clay-based building material for the manufacture of CEB. These soils are composed of quarry tailing and clayey muds. Proctor and dry compressive strength tests have shown that the proportion of mud that achieves the highest possible compressive strength is a balance between increasing density through the aggregate arrangement, increasing clay activity, and decreasing density through the increase in water content. These tests resulted in the formulation of materials with compressive strengths of 5.8 MPa and 8.4 MPa at densities of 2135 kg/m3 and 2178 kg/m3. The influence of mud incorporation on the material granulometry and on its characteristics was also studied. Moreover, a model allowing us to link the compressive strength, the clay activity, and the dry density is proposed for the materials composed of quarry by-products. This model enables us to facilitate the mix design and the standardization of the earth material.
... It is easily workable and can be manufactured in the construction site to reduce/eliminate blocks transportation. In addition to the reduction in the transportation cost and the reduction in the energy consumed in the blocks production [10], CEBs can easily be recycled into new earthen products at the end of their life [11] and they require less skilled labour than regular Concrete Masonry Blocks [12]. Furthermore, CEB optimization and stabilization techniques currently have advanced with the incorporation of industrial waste materials (e.g. ...
Article
Sustainable practices in construction industry are still facing numerous challenges despite the continuous efforts and campaigns for sustainable construction worldwide. This study aims to investigate the drivers of sustainable construction in the Kuwaiti construction industry with focus on Compressed Earth Blocks (CEBs) as an alternative sustainable construction material. It also aims to explore the level of awareness and acceptance of sustainable construction material among different stakeholders. The research was organized in three phases. The first phase identified the main drivers from relevant literature and similar studies in the past. In the second phase, a questionnaire-based survey was designs and implemented based on the findings from the literature. Two different questionnaires were designed for the survey: the first one was dedicated for stakeholders with limited knowledge about technical aspects of construction industry (owners, clients, real estate companies) and the second one was dedicated for practitioners and specialists (construction companies, engineers, project managers). In the third phase, statistical analyses were performed to compare the influence of the drivers on the stakeholders’ choices. Friedman test and Bonferroni-Dunn test were used to statistically demonstrate the level of importance of the investigated drivers. The results showed that the most influencing drivers in the choice of sustainable materials from the practitioners’ perspective are “Energy Efficiency”, “Availability and Accessibility to Resources”, “Environmental Impact”, “Enhancement of Health and Safety” and “Knowledge and Skill of Personnel” with no significant difference, followed by the “Client Demands” and the “Cost Savings” then finally the “Awareness on Sustainability”. It was also concluded that the clients’ perspective ranked the “Cost Saving” and the “Enhancement of Health and Safety” as the most important drivers followed by the “Availability and Accessibility to Resources” and the “Environmental Impact”. The survey also showed that despite the poor level of awareness on environmental sustainability, the results related to the level of acceptance of sustainable construction materials are optimistic. This observation demonstrates the readiness/willingness of clients and practitioners to shift towards sustainable construction materials, but the lack of knowledge and awareness can be the most challenging barrier to more sustainable practices. Hence, it is believed that strategies for promoting sustainability in construction industry should start by spreading knowledge among all involved stakeholders.
... It was also applied to the installation of environmentally friendly energy sources [32] considering all the criteria of ecological architecture [33]. Earthen architecture was also the subject of environmental assessment by LCA where it has been demonstrated that earth and compressed earth blocks generate less environmental impacts than their equivalents used today [34,35] and that the natural material assemblies outperform conventional assemblies, in particular, lightweight clay and insulated rammed earth, whose performance has been demonstrated in six different climate zones [36]. LCA was also applied on vernacular architecture to assess its embodied energy and CO2 emissions considering different materials and climates, where it was found that straw bales used in Chinese houses are the most carbon reducing, accounting for 91% of the total carbon reduction of low carbon building materials [37]. ...
Article
While traditional buildings have demonstrated their ability to provide a comfortable indoor thermal environment and to reduce their energy consumption, their ecological and human health performances are not widely known. This paper proposes a new approach to demonstrate and optimize the environmental performances of four traditional Saharan houses through Life Cycle Assessment (LCA), mainly by intervening on the roof, which is considered as an identifying element of this architecture type. This approach is based on a system of indicators, developing algorithmic equations for six impact categories, and combining environmental, morphological and climatic aspects. The results obtained demonstrated that the voutain allows very close environmental performances to those of ecological houses, that the ecological aspect of the cupola can only be revealed by coupling it with a very high thermal inertia and that it is recommended to use a large cupola roof rather than a multi and small cupola roof for better environmental performances. Morphological and technical parameters values were proposed as a support tool for ecological design, ensuring the sustainability of buildings in arid climates.
... Its availability and insulating properties have turned it into an excellent constructive solution throughout human history. At the end of its life, the earth can be easily recycled to produce new products, or it can be disaggregated and returned to the natural environment with a negligible environmental impact [3]. ...
Article
Full-text available
The climate crisis is one of the most important problems today. In the process of human building, the use of cement, steel, and other industrial materials in the process of building construction and recycling has brought a huge burden to the natural environment. Earth is one of the oldest building materials, its availability and insulation make it an excellent constructive solution in human history. Among several existing earth construction techniques, rammed earth is one of the most relevant. In this paper, a numerical model of the rammed earth folk house in Mianyang was established, and an experimental device was built to verify it. With the typical meteorological year data of Mianyang in northwest Sichuan, the heat and moisture transfer in rammed earth wall, as well as the indoor thermal and moisture environment were numerically simulated. The results show that the rammed earth wall weakens the temperature fluctuation of the inner surface of the wall and makes the peak temperature of the inner surface of the wall lag the outer surface. The relative humidity in the center of the rammed earth wall can be maintained at about 60%, both in winter and summer. The moisture absorption and desorption capacity of rammed earth walls without inner decorative materials is about three times that of gypsum board, and the use of a waterproof coating will render the rammed earth wall almost unable to adjust the indoor relative humidity. Additionally, the use of decorative materials will increase the fluctuation range of indoor relative humidity and the risk of mold breeding.
... . (Fernandes et al., 2019) (Giuffrida et al., 2019) (Mateus et al., 2020) (Dayaratne, 2010) (Nasrollahi & Akrami Abarghuie, 2016 ...
Thesis
Full-text available
Climate change is happening, and the necessity of sustainable development has become one of the critical current centuries' concerns. Buildings consume more than 40% of energy consumption worldwide, and producing one-third of greenhouse gas emissions has a severe impact on global warming. Iran stands at the first position in the middle east and the seventh position worldwide in greenhouse gas emissions. However, the united nations still believe for reducing these environmental impacts, we should move towards feasible and cost-effective strategies in host spots, like buildings. Because the building industry is responsible for 24% of Iranian carbon dioxide emissions and the importance of energy consumption and industrial construction materials, as well as the need for new residential buildings, it seems that this country needs a paradigm shift in material selection and buildings systems. Reviewing the potentials of vernacular architecture in the history of Iranian architecture, it appears that the use of earthen materials and traditional techniques could be the subject of further investigations. In this regard, this thesis investigates the performance of traditional techniques compared to conventional building systems with the help of embodied energy parameter. Using the standard methodology of LCA and ISO 14040, this thesis compares the embodied energy of a pilot building and a conventional one. The results show that using traditional construction techniques instead of industrial materials and systems could reduce the embodied energy of buildings up to 43% and its emitted carbon up to 48%. A separated part answers this question: what earthen material has the most minor environmental performance between adobe, break and rammed earth. Using the mentioned methodology, it concludes that adobe has better performance in embodied energy consumption with 32.5% and 19.7% of the one of break and rammed earth, respectively. Based on the results and extracted design strategies, this thesis comes to designing an elementary school. It could be concluded that earthen materials and techniques profoundly reduce buildings' energy consumption and environmental impacts. Also, due to Iran's short buildings life span, embodied energy has a vital role in buildings life cycle energy.
... Furthermore, a local material (whether vernacular, traditional or new) can intrinsically satisfy economic sustainability due to its territorial availability and capacity to generate work. [13,28] In discovering (or rediscovering) unconventional materials, however, we often encounter technical and application difficulties due to the absence of standardized production and of use and certification procedures. For these reasons Giuffrida [29], while speaking of raw earth, suggested that the reduction of the environmental impact must be pursued from a supply chain perspective. ...
Article
Full-text available
Clay has a low environmental impact and can develop into many different products. The research presents two different case studies. In the first, the clay is the binder of raw earth doughs in order to produce clay-bricks. We investigate the effects of natural fibrous reinforcements (rice straws and basalt fibers) in four different mixtures. From the comparison with a mix without reinforcements, it is possible to affirm that the 0.40% of basalt fibers reduce the shrinkage by about 25% and increase the compressive strength by about 30%. Future studies will focus on identifying the fibrous effects on tensile strength and elastic modulus, as well as the optimal percentage of fibers. In the second study, the clay, in form of brick powder (“cocciopesto”), gives high alkaline resistance and breathability performance, as well as rendering and color to the plaster. The latter does not have artificial additives. The plaster respects the cultural instance of the original building. The research underlines how the use of a local (and traditional) material such as clay can be a promoter of sustainability in the contemporary building sector. Future studies must investigate further possible uses of clay as well as a proper regulatory framework.
Chapter
This paper investigates the effect of integrating Alfa fibers into compressed earth blocks (CEBs) stabilized with varying Portland cement contents. CEB composites were manufactured with earth stabilized using different cement contents (5 and 10% by weight) and Alfa fibers reinforcement (0–0.4% by weight), compressed at 10 MPa with a compaction loading press. After 28 days of drying, the CEBs underwent diverse experimental tests to evaluate their physical, mechanical, and durability properties. The findings indicated that incorporating fibers led to a diminution in unit weight, ultrasonic pulse velocity, and dry compressive strength. Despite the drop in mechanical strength, CEBs with lower cement (5%) and higher fiber content (0.4%) demonstrated satisfactory erosion resistance, which could play a crucial role in areas prone to extreme weather events (floods and storms). According to this study, this material has the potential as a promising composite for building materials and reducing the need for cement, which is deemed a major contributor to greenhouse gas emissions in the construction industry. The results have implications for affordable housing solutions and offer insightful information about sustainable building materials.
Article
This paper investigates the effect of integrating Alfa fibers into compressed earth blocks (CEBs) stabilized with varying Portland cement contents. CEB composites were manufactured with earth stabilized using different cement contents (5% and 10% by weight) and Alfa fibers reinforcement (0–0.4% by weight), compressed at 10 MPa with a compaction loading press. After 28 days of drying, the CEBs underwent diverse experimental tests to evaluate their physical, mechanical, and durability properties. The findings indicated that incorporating fibers led to a diminution in unit weight, ultrasonic pulse velocity, and dry compressive strength. Moreover, an increase in water absorption was linked with higher fiber content and less cement stabilizer. Despite the drop in mechanical strength, CEBs with lower cement (5%) and higher fiber content (0.4%) show better thermal performance. Thermal conductivity values were decreased from 0.5166 W/m.K (10% cement without fibers) to 0.3465 W/m.K (5% fibers with 0.4% fibers). The findings show also satisfactory erosion resistance, which could play a crucial role in areas prone to extreme weather events (floods and storms). According to the findings of this research, this material has potential as a promoting composite for the building materials industry.
Article
Full-text available
Purpose Climate change, environmental concerns, and economic problems pose challenges to the construction sector in Iran, which must provide affordable solutions while addressing environmental issues. Hence, natural earthen building materials are critically needed to reduce energy-intensive and costly construction practices dramatically. The purpose of this paper is to provide a framework for comparing life cycle assessments (LCA) and life cycle costs (LCC), for load-bearing walls of an single-family affordable housing unit in a desert part of Iran, Ardakan City. Methods To do so, both LCA and LCC for the unit were performed, considering a cradle-to-site perspective. For this purpose, 22 load bearing wall systems are assessed, including 18 stabilized and unstabilized earthen construction techniques, such as adobe, rammed earth (RE), and compressed earth block (CEB), in addition to four conventional wall assemblies of fired brick (FB), autoclaved aerated concrete block (AAC), ceramic block (CB), and concrete masonry unit (CMU). As well as assessing the environmental impact and life cycle costs associated with the life cycle of each wall, the optimal assembly of the wall is also examined. Results Results show that unstabilized earthen walling alternatives have significantly lower environmental impacts than conventional materials. Conclusions Sensitivity analysis indicates that by utilizing local materials to the maximum extent possible, impacts can be further minimized. Considering the results, transportation may even account for a greater proportion of EI than wall components.
Article
Earthen buildings frequently demand the use of protective renders and plasters that should be, in several aspects, compatible with the underlying structures. To this end, earth-based mortars have traditionally been used and are common in historic houses. Their periodic replacement or repair is inevitable and intrinsic with their naturally sacrificial role, but restorations are also expected to follow suitability criteria, as well as minimum performance standards. In this paper, an approach to the reproduction of wall-finishes close to the original formulations found on historic buildings is proposed and described using the case study of a historic site in Brazil. The problem was addressed using the elemental composition data of a set of original mortars and a bank of local soils that were treated by multivariate statistical analysis. The final restoration mortars, that were obtained also by adjusting their granulometric profile by means of the mixture of sand, exhibited satisfactory performance in terms of adhesive strength and water absorption, as well as of resistance to water erosion when stabilized with lime.
Article
Compressed Earth Blocks (CEBs) have been attracting increasing research interest recently, because of their sustainable nature. While these earth-based materials have long been used in heritage and contemporary buildings worldwide, their poor performance against water-mediated weathering is still considered to be a major drawback. The aim of this study is to examine the durability performance of non-stabilized CEBs currently produced in Cyprus and to enhance their resistance against water-mediated weathering by optimizing their granular composition. To that end, four soils originating from specific areas of the island, which have been well-known for their rich tradition in earthen heritage buildings, namely adobe masonry, and a fine crushed aggregate were used to produce several CEBs. These were examined both at macroscopic and microscopic level, while spray erosion, drip, capillary absorption and wet/dry appraisal tests were carried out to assess their performance against water attack. The results show that more than one testing methodologies have to be used to fully assess the resistance of CEBs against water decay. They also suggest that the addition of sand can significantly improve the durability of non-stabilized CEBs against water-mediated weathering. This may prove to be a benefit both for restoration projects and contemporary constructions with the use of CEBs.
Article
This paper investigates the feasibility of using an industrial by-product from cement manufacturing known as cement kiln dust (CKD) to improve mechanical, thermal and durability properties of compressed earth blocks (CEB). The CEB are made from local clay types partially replaced by CKD at contents of 5 %, 10 %, 15 %, 20 %, and 25 % by mass, and compacted using a hydraulic press. Tests were performed on the blocks to define their properties. The study findings outline an improvement in the mechanical properties and the durability of the CEB without compromising the thermal properties. The compressive strength of the CEB with 25 % CKD at 60 days was about three times higher than those without CKD. With 0 % and 5 % CKD, the best values for thermal conductivity were recorded, i.e. 0.89 W/m K and 0.90 W/m K respectively. The durability criteria of the CEB were respected, with an abrasion resistance characterized by the maximum abrasion coefficient reached with 25 % CKD, which equals about 28.5 cm²/g, and a capillary absorption of 0.06 g/cm² min1/2 for the same percentage, thus meeting the recommendations of the French standard NF P13-901.
Article
The construction with compressed earth blocks (CEB) has provoked special worldwide interest in recent decades. In Argentina it has considerable experiences due to technical research, its use in public works and the development of some manufacturing units at different scales. The particular interest of its technology transfer to low income population sectors has been central and defines the social profile with which it has been implemented in the last time. However, its contemporary development has a low territorial impact due to the fact that problems are observed that hinder the implementation, dissemination, economic support of the manufacture and CEB commercialisation and the transfer of this technology. The aim of this article is to characterize and discuss the nature of the problems that hinder further development of CEB construction technology in Argentina. Local scientific production was analysed and the agents involved in the CEB production process were identified, who were surveyed and interviewed asking their assessment of the problems that affect the development of this technology today. The results show that the technical aspects involved in the CEB manufacturing stage are the ones that have received the most attention so far, much of the current difficulties to continue with its development are focused on the implementation, dissemination, and economic sustainability of the CEB manufacturing and commercialisation and the transfer of this technology. The lack of a specific regulatory framework for this technology is transversal to these problems mentioned. With regard to the scientific field, these issues need to be incorporated into research agendas, at least at the local level.
Article
Full-text available
Solar passive strategies that have been developed in vernacular architecture from different regions are a response to specific climate effects. These strategies are usually simple, low-tech and have low potential environmental impact. For this reason, several studies highlight them as having potential to reduce the demands of non-renewable energy for buildings operation. In this paper, the climatic contrast between northern and southern parts of mainland Portugal is presented, namely the regions of Beira Alta and Alentejo. Additionally, it discusses the contribution of different climate-responsive strategies developed in vernacular architecture from both regions to assure thermal comfort conditions. In Beira Alta, the use of glazed balconies as a strategy to capture solar gains is usual, while in Alentejo the focus is on passive cooling strategies. To understand the effectiveness of these strategies, thermal performances and comfort conditions of two case studies were evaluated based on the adaptive comfort model. Field tests included measurement of hygrothermal parameters and surveys on occupants' thermal sensation. From the results, it has been found that the case studies have shown a good thermal performance by passive means alone and that the occupants feel comfortable, except during winter where there is the need to use simple heating systems.
Article
Full-text available
Nearly two million residential building are built annually in India apart from the offices, commercial and industrial buildings with demand and supply which is increasing year by year. It is essential to conserve the conventional energy by developing energy efficient buildings. Environmental quality and conservation of fossil fuels may become important in the context of limiting of GHGs emission and also reducing cost of materials. The most important stages from point of view of energy intensity: (a) Raw material acquisition; (b) Preparation & Manufacturing;(c) Transportation But this paper broadly considered to analyze the first two parts as the third part of transportation energy vary from location to location, however it has been emphasized in the literature that 1 MJ/ tonne /km (diesel) for transporting materials can be integrated for location specific analysis. Besides, Energy estimates given in the literature for various materials such as the Cement 5.85 MJ/kg, lime 5.62 MJ/kg, LP 2.33 MJ/kg (lime 30%, Pozzolana 60% and 10%calcined gypsum), steel 42 MJ/kg, Al 236.8 MJ/kg, Glass 25.8Mj/kg, Burnt clay brick 4.25 MJ, Hollow block 12.3-15 MJ, etc have been considered for energy appraisal. It is focused on some issues pertaining to Embodied Energy savings by identifying a few appropriate options for important building components and a comparison of energy in different types of roof and terracing has been made. Energy in different options of alternative systems have been discussed and compared with the energy consumed in conventional specifications to appreciate the consumption of energy in various materials for selection of appropriate materials with reference to energy savings and sustainable development.
Article
Full-text available
Vernacular architecture is characterised by a type of formal expression, which has been developed in response to a number of factors - geographic, climatic and economic - characterising the local area or region. Despite the fact that Portugal is a small country, there are many different architectural approaches and a range of techniques have been employed in different regions to mitigate the effects of climate. These vernacular approaches have the potential for further development and could be adapted in response to contemporary needs. In this paper, a range of different passive solar techniques used in Portuguese vernacular architecture to provide comfort is presented. The specific focus is on the effectiveness of passive cooling strategies (namely, high thermal inertia, use of light colours and courtyards), and the findings of a case study in which the thermal performance during the summer of a vernacular residential building located in the south of Portugal are presented.
Chapter
Full-text available
Vernacular architecture embodies a plurality of constraints from places where it belongs, in which the use of local materials and techniques is one of the main features. When compared with industrially-produced materials, vernacular materials have low environmental impacts, being an alternative for sustainable construction. The increasing use of new industrially-produced and standardized materials led to the homoge-nization of the different used construction approaches, and spawned a universal architecture that in many cas-es is out of the environment context and is very dependent on energy and other resources. This paper address-es the relation between Portuguese vernacular architecture and locally sourced materials, relating them with the territory lithology, agricultural crops and the climate. To assess the contribution of these materials for sus-tainability, a comparison with industrial materials at level of environmental indicators was established. This paper highlights the advantages of using local materials and techniques as a factor of local socio-economic development.
Article
Full-text available
Energy consumption in the buildings sector is very high and is expected to increase further due to improvements in living standard and increase in the world’s population. Incorporating appropriate solar passive features in climate responsive buildings are good options for energy conservation. This kind of building design integrates the micro-climate and architecture with human thermal comfort conditions and improves the building energy efficiency. From ancient times, people have used solar passive techniques in vernacular architectures throughout the world. However, still there is a lack of understanding, both in qualitative and quantitative aspects of solar passive techniques in vernacular architectures of North-Eastern India. A field study has been carried out to find out the various solar passive features in these naturally ventilated vernacular buildings in different bioclimatic zones of the region. The methodology of this work consists of survey of 150 households (50 houses in each bioclimatic zone) and, interacting with 300 occupants in each zone. The photographic evidences of solar passive features in these buildings are also collected. In this paper, the solar passive features related to building form and orientation, envelope design, shading, use of natural ventilation, internal space arrangements and activities of the habitants are explained for all the climatic zone of the region.
Article
Buildings use approximately 48% of global energy each year in their construction and operation as embodied and operating energy. The embodied energy is used directly through onsite and offsite construction and related processes, and indirectly through the use of materials and equipment. The embodied energy used in a building's construction is called initial embodied energy (IEE), whereas the energy embodied in the recurring processes of maintenance, repair, and replacement is termed recurrent embodied energy (REE). To effectively optimize a building's life cycle embodied energy, both the REE and IEE must be evaluated collectively. However, a building's REE depends on multiple parameters, which can cause significant variations of REE results across studies. A thorough investigation of parameters specific to REE calculation is currently lacking. The REE parameters may introduce significant uncertainties in the life cycle embodied energy calculations. In this paper, we perform a systematic review of literature to identify key parameters affecting REE calculations. We also propose a framework to identify and quantify the uncertainties resulting from these parameters. The findings of this study will help streamline the process of life cycle embodied energy calculation.
Article
Nowadays, the concrete production sector is challenged by attempts to minimize the usage of raw materials and energy consumption, as well as by environmental concerns. Therefore, it is necessary to choose better options, e.g. new technologies or materials with improved life-cycle performance. One solution for using resources in an efficient manner is to close the materials' loop through the recycling of materials that result either from the end-of-life of products or from being the by-product of an industrial process. It is well known that the production of Portland cement, one of the materials most used in the construction sector, has a significant contribution to the environmental impacts, mainly related with carbon dioxide emission. Therefore, the study and utilization of by-products or wastes usable as cement replacement in concrete can supply more sustainable options, provided that these types of concrete produced has same durability and equivalent quality properties as standard Concrete. This work studied the environmental benefits of incorporating different percentages of two types of fly ashes that can be used in concrete as cement replacement. These ashes are waste products of power and heat production sectors using coal or biomass as fuels. The results showed that both ashes provide a benefit for the concrete production both in terms of environmental impact minimization and a better environmental performance through an increase in cement replacement. It is possible to verify that the incorporation of fly ashes is a sustainable option for cement substitution and a possible path to improve the environmental performance of the concrete industry.
Article
The advantages and disadvantages of the thermal building insulation materials and solutions have been treated. Both traditional, state-of-the-art and possible materials and solutions beyond these have been investigated. Examples of these may be mineral wool, expanded polystyrene, extruded polystyrene, polyurethane, vacuum insulation panels, gas insulation panels, aerogels, and future possibilities like vacuum insulation materials, nano insulation materials and dynamic insulation materials. Various properties, requirements and possibilities have been compared and studied. Among these are thermal conductivity, perforation vulnerability, building site adaptability and cuttability, mechanical strength, fire protection, fume emission during fire, robustness, climate ageing durability, resistance towards freezing/thawing cycles, water resistance, costs and environmental impact. Currently, there exist no single insulation material or solution capable of fulfilling all the requirements with respect to the most crucial properties. That is, for the buildings of today and the near future, several insulation materials and solutions are used and will have to be used depending on the exact circumstances and specifications. As of today, new materials and solutions like e.g. vacuum insulation panels are emerging, but only slowly introduced in the building sector partly due to their short track record. Therefore it will be of major importance to know the limitations and possibilities of all the insulation materials and solutions, i.e. their advantages and disadvantages. In this respect new conceptual thermal building insulation materials are also discussed.
Article
The paper shows how sustainability questions relate to the local space. The local place is not a static entity, but a dynamic one, undergoing constant changes, and it is the rapid social and material processes within the given local situation that is a challenge for the Chinese villages and their integrity. The following article considers the cohesion between the dwellers' emotional co-ownership of their local space and the sustainability process as a driving force in social, economic and ecological development. We bring together the classification of the seven fields of encounter, which were developed out of the empirical data of the Chinese case study villages, and sustainability oriented management considerations for all levels of this concept. We do not pretend to know the solutions, but describe a set of interrelated fields that can be anchor points for placing the solutions and show in which fields action and intervention is possible. In our concept of sustainability, every spatial field has its special meaning, needs special measures and policies and has different connotations to concepts like responsibility, family values or communication systems. We see the social sustainability process as a support for the empowerment of the local dwellers, and the SUCCESS research has encouraged the villages to find suitable sustainability oriented solutions for their natural and societal situation. Before entering the discussion about the chances and potential of a sustainability approach for the Chinese villages, it is first necessary to accept the fact that rural villages play a primordial role in Chinese society and that their potential can strengthen future pathways for China.
Sustainability assessment of an energy efficient optimized solution
  • R Mateus
  • S Silva
  • L Bragança
  • M Almeida
  • P Silva
Mateus, R., Silva, S., Bragança, L., Almeida, M., Silva, P., 2007. Sustainability assessment of an energy efficient optimized solution. In: Santamouris, M., Wouters, P. (Eds.) Proceedings of the 2nd PALENC Conference and 28th AIVC Conference on Building Low Energy Cooling and Advanced Ventilation Technologies in the 21st Century. Heliotopos: Heliotopos Conferences, pp. 636-640.
Contributo para a melhoria do desempenho térmico das paredes de taipa
  • J P B Pereira
  • J J Correia Da Silva
Pereira, J.P.B., Correia da Silva, J.J., 2012. Contributo para a melhoria do desempenho térmico das paredes de taipa. In: Congresso Construção 2012 -4. o Congresso Nacional. Coimbra: Universidade de Coimbra, Faculdade de Ciências e Tecnologia.