Fair Play: Why Reliable Data for Low-Tech Construction and Non-conventional Materials Are Needed

The paper proposes considerations stemming from the analysis of twenty-two buildings that show different approaches to ‘vegetarian architecture’—a theoretical stance based on principles learnt from agriculture and nutrition. The first phase consisted in a systematic investigation of the constructional characteristics of each building, and the cataloguing of their components. The ‘cradle to gate’ embodied energy (EE) and ‘embodied carbon’ (EC) were then calculated, based on two open access databases: ICE and Ökobaudat. The applicability of these databases was considered, as they do not cover low industrialised bio-based construction materials. For some materials, data are missing; while in others, EE values are overestimated since high energy-intensive manufacturing processes seem to be assumed. In a second phase, the uses and production process of some non-conventional materials was investigated, evidencing their variability. Building technologies that are not just aimed at low operational energy but at a more holistic understanding of low environmental impact represent a paradigm shift in ‘sustainable’ construction prac-tices. Despite ongoing actions and policies, as long as these materials and techniques are not suitably represented in reliable and accessible databases, it will be difficult to make such a shift happen. Manufacturers and contractors who produce and use such materials would benefit from the availability of easily applicable, scientific data demonstrating environmental advantages offered by non-conventional materials

Industrial or traditional bamboo construction? Comparative life cycle assessment (LCA) of bamboo-based buildings

© 2018 by the authors. The past five decades have witnessed an unprecedented growth in population. This has led to an ever-growing housing demand. It has been proposed that the use of bio-based materials, and specifically bamboo, can help alleviate the housing demand in a sustainable manner. The present paper aims to assess the environmental impact caused by using four different construction materials (bamboo, brick, concrete hollow block, and engineered bamboo) in buildings. A comparative life cycle assessment (LCA) was carried out to measure the environmental impact of the different construction materials in the construction of single and multi-storey buildings. The LCA considered the extraction, production, transport, and use of the construction materials. The IPCC2013 evaluation method from the Intergovernmental Panel on Climate Change IPCC2013 was used for the calculations of CO2 emissions. The assessment was geographically located in Colombia, South America, and estimates the transport distances of the construction materials. The results show that transportation and reinforcing materials significantly contribute to the environmental impact, whereas the engineered bamboo construction system has the lowest environmental impact. The adoption of bamboo-based construction systems has a significant potential to support the regenerative development of regions where they could be used and might lead to long-lasting improvements to economies, environments, and livelihoods

Bamboo reinforced concrete: a critical review

© 2018, The Author(s). The use of small diameter whole-culm (bars) and/or split bamboo (a.k.a. splints or round strips) has often been proposed as an alternative to relatively expensive reinforcing steel in reinforced concrete. The motivation for such replacement is typically cost—bamboo is readily available in many tropical and sub-tropical locations, whereas steel reinforcement is relatively more expensive—and more recently, the drive to find more sustainable alternatives in the construction industry. This review addresses such ‘bamboo-reinforced concrete’ and assesses its structural and environmental performance as an alternative to steel reinforced concrete. A prototype three bay portal frame, that would not be uncommon in regions of the world where bamboo-reinforced concrete may be considered, is used to illustrate bamboo reinforced concrete design and as a basis for a life cycle assessment of the same. The authors conclude that, although bamboo is a material with extraordinary mechanical properties, its use in bamboo-reinforced concrete is an ill-considered concept, having significant durability, strength and stiffness issues, and does not meet the environmentally friendly credentials often attributed to it

Method and application of characterisation of life cycle impact data of construction materials using geographic information systems

Purpose: This research presents a methodology to characterize life cycle impact data (LCIA) of alternative construction materials outside of the European context. Methods: This methodology was based on the characterization of data and life cycle assessment (LCA) using geographic information systems (GIS), which has been proposed as an effective alternative for this purpose. The data were characterized at three levels: global, represented by different production efficiency of materials; regional, represented by the type of electricity mix used in the production and the national transport at the country level; and local, represented by external factors, such as seismic and wind risk zones at the city level. A comparative LCA was used as case study to test the methodology. The functional unit for the LCA was defined as an 18 m2 core shelter unit consisting of structural elements only. The bill of materials for five designs were calculated, each using a distinctive construction material: bamboo, brick, concrete hollow block, ferro-cement panels, and soil-stabilised bricks. The contributions’ variability and uncertainty analysis were used to validate the consistency of the results. The effect of the external constraints (earthquakes and wind) were analysed, and the environmental impact over the whole life cycle was assessed. Five house designs were calculated in twenty locations based on three levels of production efficiency and three transport distance ranges for each country. Results and discussion: The results of the bamboo, concrete hollow block and ferro-cement houses overlapped and changed depending on the construction materials’ transport distance. Therefore, the level of impact of an average bamboo house can also be achieved by a high-performance block or ferro-cement house. The results showed that in most cases, the buildings with high technical performance can be achieved with low environmental impacts. Conclusions: The use of GIS enables the development of characterized LCIA data for construction materials and buildings with a high degree of consistency. Moreover, the proposed approach was able to accurately represent the range of production practices used outside Europe. Finally, the use of the proposed methodology allows for the assessment of building in the early stages of design when uncertainty is at its highest, thereby identifying the improvement potential of each design and recognising the structural needs in specific locations

Environmental Savings from the use of Vegetable Fibers as Concrete Reinforcement

The growing interest in sustainable construction materials has brought back the spotlight to the use of bio-fibers as reinforcement of concrete. Bio-fiber reinforced concrete elements can achieve mechanical properties comparable to traditional products with added values as coming from renewable sources, being less expensive and opening new possibilities for concrete recycling. The life cycle inventories of both traditional and bio-fiber reinforced products were developed using SIMA pro. Moreover, life cycle assessments were carried out in order to represent different scenarios considering amounts of materials required; energy demands due to processing, transportation and disposal. It was concluded that the use of bio-fibers as reinforcement for concrete can produce a significant environmental saving only under certain conditions. These were noticeably influenced by material quantities while factors like transport, disposal, or possibilities of recycling of the studied products did not produce a significant impact. The replacement of traditional reinforcements can not only bring a significant environmental saving for the production of concrete but carries also a remarkable cost reduction potential, making it an interesting option for the ever growing demand of housing in the developing world, where many of the bio-fibers grow naturally, thus opening new opportunities for sustainable and affordable construction materials, employment generation, and business

Environmental Savings from the use of Vegetable Fibers as Concrete Reinforcement

The growing interest in sustainable construction materials has brought back the spotlight to the use of bio-fibers as reinforcement of concrete. Bio-fiber reinforced concrete elements can achieve mechanical properties comparable to traditional products with added values as coming from renewable sources, being less expensive and opening new possibilities for concrete recycling. The life cycle inventories of both traditional and bio-fiber reinforced products were developed using SIMA pro. Moreover, life cycle assessments were carried out in order to represent different scenarios considering amounts of materials required; energy demands due to processing, transportation and disposal. It was concluded that the use of bio-fibers as reinforcement for concrete can produce a significant environmental saving only under certain conditions. These were noticeably influenced by material quantities while factors like transport, disposal, or possibilities of recycling of the studied products did not produce a significant impact. The replacement of traditional reinforcements can not only bring a significant environmental saving for the production of concrete but carries also a remarkable cost reduction potential, making it an interesting option for the ever growing demand of housing in the developing world, where many of the bio-fibers grow naturally, thus opening new opportunities for sustainable and affordable construction materials, employment generation, and business

Economic, ecological and building physical optimization of a wooden building envelope for subtropical regionas

With regard to the resource depletion and the global climate change, the construction industry is important for the realization of a sustainable society. In this study, a wooden envelope system for subtropical regions was investigated in order to find the optimal wood fiber insulation thickness. The analyses were done by weighting the initial investment and the running cost form the ecological and economic viewpoint. The building physically minimum insulation thickness was also calculated by hygrothermal models. It was shown that the ecological optimum is more costly than the economical optimum. I was also shown that the building physical minimum is dependent on the local climatic conditions. By conducting the analyses in terms of the ecology, economy and the building physics, it was able to identify the regions that the envelope system works more sustainably

A matter of speed: The impact of material choice in post-disaster reconstruction

The effects of urbanization and climate change are dangerously converging. The most affected populations are the urban poor, settled in informal settlements vulnerable to increasingly frequent disasters. This severely contributes to the existing housing gap of these regions, already struggling with housing demand. The speed of shelter delivery becomes key for an efficient response in order to prevent spontaneous informal resettlements on unsafe lands. The present study aims to understand the impact of material choice on post-disaster shelters delivery through a multiscale analysis of construction speed. The scales considered are: Constructive technology, Shelter Unit and Post-disaster settlement. At the the Constructive technology scale, nine different reconstruction solutions for the Nepal earthquake are compared, covering a range from local to industrialized. Successively, twelve shelter designs by the International Federation of the Red Cross have been studied under the same lens at the Shelter unit scale and for Post-disaster settlements. The study identifies a clear correlation between material procurement and speed at the constructive technology scale. At the shelter scale, this correlation becomes secondary and construction time is seriously impacted by the complexity of roof design. Moving to the settlement scale, the choice of local over industrialized materials seems to drive the speed again. The study indicates how a multiscale approach is necessary to analyze the impacts of material selection, providing efficient guidelines for post-disaster reconstruction. Beyond that, it highlights that effective reconstruction can be developed with diverse materials, but its emergency responsiveness can seriously be compromised by a non-appropriate design