Environmental Impact of a Mass Timber Building—A Case Study

The study focuses on a life cycle assessment of a wood-based residential building and evaluates the magnitude of individual construction components—foundations, flooring, peripheral wall, inner walls, ceiling, roof, windows, and doors—in terms of climate change; acidification; eutrophication; photochemical oxidation; depletion of abiotic elements and fossil fuels; and water scarcity categories within the system boundaries of the Product stage of the life cycle. The assessment was done using the SimaPro software and the ecoinvent database. The results pointed at the advantages of mass timber as a construction material and highlighted the significance in the type of insulation used. Foundations were found to bear the highest share of impact on photochemical oxidation reaching nearly 30% and depletion of fossil fuels accounting for about 25% of that impact. Peripheral wall was ranked the worst in terms of impact on acidification and eutrophication (more than 25% of both), depletion of elements (responsible for 50% of that impact), and had about 60% impact on water scarcity. After adding up carbon emissions and removals, the embodied impact of the whole construction on climate change was detected to be 8185.19 kg CO2 eq emissions which corresponded with 57.08 kg CO2 eq/m2 of gross internal area. A negative carbon composition of the construction was also set.

Life Cycle Assessment of an Oscillating Wave Surge Energy Converter

So far, very few studies have focused on the quantification of the environmental impacts of a wave energy converter. The current study presents a preliminary Life Cycle Assessment (LCA) of the MegaRoller wave energy converter, aiming to contribute to decision making regarding the least carbon- and energy-intensive design choices. The LCA encompasses all life cycle stages from “cradle-to-grave” for the wave energy converter, including the panel, foundation, PTO and mooring system, considering its deployment in Peniche, Portugal. Background data was mainly sourced from the manufacturer whereas foreground data was sourced from the Ecoinvent database (v.3.4). The resulting impact assessment of the MegaRoller is aligned with all previous studies in concluding that the main environmental impacts are due to materials use and manufacture, and mainly due to high amounts of material used, particularly steel. The scenario analysis showed that a reduction of the environmental impacts in the final design of the MegaRoller wave energy converter could potentially lie in reducing the quantity of steel by studying alternatives for its replacement. Results are generally comparable with earlier studies for ocean technologies and are very low when compared with other power generating technologies.

Environmental and Social Impact Assessment of Optimized Post-Tensioned Concrete Road Bridges

Most of the definitions of sustainability include three basic pillars: economic, environmental, and social. The economic pillar has always been evaluated but not necessarily in the sense of economic sustainability. On the other hand, the environmental pillar is increasingly being considered, while the social pillar is weakly developed. Focusing on the environmental and social pillars, the use of methodologies to allow a wide assessment of these pillars and the integration of the assessment in a few understandable indicators is crucial. This article is structured into two parts. In the first part, a review of life cycle impact assessment methods, which allow a comprehensive assessment of the environmental and social pillars, is carried out. In the second part, a complete environmental and social sustainability assessment is made using the ecoinvent database and ReCiPe method, for the environmental pillar, and SOCA database and simple Social Impact Weighting method, for the social pillar. This methodology was used to compare three optimized bridges: two box-section post-tensioned concrete road bridges with a variety of initial and maintenance characteristics, and a pre-stressed concrete precast bridge. The results show that there is a high interrelation between the environmental and social impact for each life cycle stage.

Light Weight, Easy Formable and Non-Toxic Polymer-Based Composites for Hard X-ray Shielding: A Theoretical and Experimental Study

Composite lightweight materials for X-ray shielding applications were studied and developed with the goal of replacing traditional screens made of lead and steel, with innovative materials with similar shielding properties, but lighter, more easily formed and workable, with lower impact on the environment and reduced toxicity for human health. New epoxy based composites additivated with barium sulfate and bismuth oxide were designed through simulations performed with softwares based on Geant4. Then, they were prepared and characterized using different techniques starting from digital radiography in order to test the radiopacity of the composites, in comparison with traditional materials. The lower environmental impact and toxicity of these innovative screens were quantified by Life Cycle Assessment (LCA) calculation based on the ecoinvent database, within the openLCA framework. Optimized mixtures are (i) 20% epoxy/60% bismuth oxide/20% barite, which guarantees the best performance in X-ray shielding, largely overcoming steel, but higher in costs and a weight reduction of circa 60%; (ii) 20% epoxy/40% bismuth oxide/40% barite which has slightly lower performances in shielding, but it is lighter and cheaper than the first one and (iii) the 20% epoxy/20% bismuth oxide/60% barite which is the cheapest material, still maintaining the X-ray shielding of steel. Depending on cost/efficiency request of the specific application (industrial radiography, aerospace, medical analysis), the final user can choose among the proposed solutions.

Designing sustainable footbridges: comparing steel, concrete and FRP.

<p>More and more clients and the public are asking for sustainable and circular solutions for infrastructure. Many opinions and often prejudice exist on the sustainability of each material. However, sustainability is just as much a design property as a material property. To illustrate how choices made by the designer affect the environmental impact of the structure, this study compares solutions in steel, concrete and Fibre Reinforced Polymer (FRP) for footbridges of 15m and 25m span as they exist today. Boundary conditions have been set in advance and the designs have been prepared to the same level of depth by senior engineers with comparable expertise in the respective materials. The concepts have been compared on CO₂-emissions over the life cycle, including maintenance. End-of-life (EoL) scenarios are described qualitatively but it is debated how to include these in the CO₂-emissions, as in a 100 years’ time technologies for recycling will be substantially different from today’s. Including the EoL in this comparison study therefore means that a uncertain parameter is made part of the equation. Use has been made of the EcoInvent database and the EuCIA Eco Impact Calculator, an environmental impact tool developed by the FRP industry association using the latest data available on FRP. This paper identifies the challenges in the assessment of sustainability of the designs, the relevance of certain design parameters and discusses how to deal with future EoL aspects in today’s assessment.</p>