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

Wood in buildings: the right answer to the wrong question

Reducing the embodied emissions of materials for new construction and renovation of buildings is a key challenge for climate change mitigation around the world. However, as simply reducing emissions is not sufficient to meet the climate targets, using bio-based materials seems the only feasible choice as it permits carbon storage in buildings. Various studies have shown that bio-based materials allow turning overall life cycle impacts negative, therefore, having a cooling effect on the climate. In recent years, scholars and policy makers have focused almost exclusively on the advancement of wooden buildings. Timber structures stand out as they can be prefabricated and used for high-rise buildings. Yet, one important aspect seems to be overlooked: the consideration of supply and demand. Large forest areas that allow sustainable sourcing of woody biomass only exist in the Northern hemisphere, notably in North America and Europe. In these regions, though, urbanization rates are mostly stagnating, meaning new construction rates are low. The largest amount of material requirements in these regions are derived from the refurbishment of the existing stock. Moreover, in areas where structural material is needed for new construction, in Asia, Africa and South America, rain forests need to be protected. Therefore, we need to rethink the desire to find one solution and carelessly implement it everywhere. Instead, we need to consider locally available material and know-how for grounded material choices. This paper explores the supply of a range of bio-based materials and matches it against the material demand of global building stocks. It is based on various previous studies by the authors, of South Africa, China, Portugal, and more. The analysis divides between structural materials for new construction, such as wood and bamboo, and thermal insulation materials for the refurbishment of existing buildings, such as straw and hemp. The results emphasize the need for diversifying bio-based material solutions

Global or local construction materials for post-disaster reconstruction? Sustainability assessment of 20 post-disaster shelter designs

This data article presents the life cycle inventories of 20 transitional shelter solutions. The data was gathered from the reports 8 shelter designs [1]; 10 post-disaster shelter designs [2]; the environmental impact of brick production outside of Europe [3]; and the optimization of bamboo-based post-disaster housing units for tropical and subtropical regions using LCA methodologies [4]. These reports include bill of quantities, plans, performance analysis, and lifespan of the studied shelters. The data from these reports was used to develop the Life Cycle Inventories (LCI). All the amounts were converted from their original units (length, volume and amount) into mass (kg) units and the transport distance into ton×km. These LCIs represent the production phases of each shelter and the transportation distances for the construction materials. Two types of distances were included, local (road) and international (freight ship), which were estimated based on the area of the country of study. Furthermore, the digital visualization of the shelters is presented for each of the 20 designs. Moreover, this data article presents a summary of the results for the categories Environment, Cost and Risk and the contribution to the environmental impact from the different building components of each shelter. These results are related to the article “Global or local construction materials for post-disaster reconstruction? Sustainability assessment of 20 post-disaster shelter designs”[5

Comparative Life Cycle Assessment of Two “Vegetarian Architecture” Pavilions

The goal to achieve carbon neutrality in the built environment by 2040 becomes more challenging every day.Moreover, the challenge goes beyond energy efficiency and embodied energy, and includes the quality of life of buildings’ occupants. Under this framework it becomes clear that a radical change is needed in the current construction practices. In this sense, ‘Vegetarian Architecture’ advocates a closer relationship with construction materials and an increased use of regionally produced and locally available materials and building techniques. The paper showcases two ‘VegetarianArchitecture’ pavilions built in Northern Italy: one with a load-bearing straw bale structure and the other with a light-earth infilled timber frame. We detail the local material selection and transportation processes, as well as provide bills of quantities. The comparative Life Cycle Assessment considers production, construction, and operation stages following EN15978, with Ecoinvent 3.8 database and OpenLCA software. IPCC2021 evaluates carbon footprint, and EN16449 assesses stored biogenic CO2. The contribution analysis found that as material production approaches carbon zero, transportation becomes more important. However, due to the low carbon footprint of the two pavilions studied, transportation distances could be increased without a significant impact. Additionally, the use of fast-growing, locally sourced, bio-based materials like straw and reed allows the pavilions to store significant amounts of biogenic CO2, making them carbon negative. Vegetarian Architecture not only promotes alternative materials but also facilitates the development of local value chains and inter-sectoral synergies

Sociodemographic correlates and family aggregation of leukocyte telomere length in adults and children from Mesoamerica

ObjectiveTelomere length is a biomarker of cumulative stress and inflammation related to chronic disease risk. We examined the associations of leukocyte telomere length (LTL) with sociodemographic and anthropometric variables and estimated LTL family aggregation in Central America, a region with a high burden of chronic disease where LTL has not been studied.MethodsWe conducted a crossâ sectional study of 174 school age children and their parents in the capital cities of Belize, Honduras, Nicaragua, Costa Rica, Panama, and the city of Tuxtlaâ Gutierrez in Mexico. We measured LTL by quantitative PCR in DNA extracted from whole blood. We compared the distribution of LTL by categories of sociodemographic and anthropometric characteristics using linear regression. Family aggregation was estimated with correlation coefficients and intraclass correlations.ResultsIn mothers, LTL was inversely associated with age (P, trendâ <â .0001) and positively associated with height (Pâ =â .0002). Among fathers, LTL was inversely associated with food insecurity (P, trendâ =â .0004). In children, boys had 0.10 log units shorter LTL than girls (95% CI: â 0.17, â 0.03; Pâ =â .004). LTL was inversely associated with parental education (P, trendâ =â .01) and positively associated with paternal age at birth (P, trendâ <â .0001), maternal LTL (P, trendâ =â .007), and paternal LTL (P, trendâ =â .02). LTL varied significantly by country of origin among all family members. Aggregation was greatest between children and their mothers, and mostly occurred at the country, rather than family, level.ConclusionLTL is associated with age and height in women; food insecurity in men; and sex, parental education, parental LTL, and paternal age at birth among children.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/137202/1/ajhb22942.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/137202/2/ajhb22942_am.pd