Embodied energy as an environmental impact indicator for basement wall construction

Attempts were made to quantify the environmental impacts of the basement walls of two commercial buildings in London. Four different retaining wall options were designed based on steel and concrete systems for each of the sites. It was considered that excavation would take place with the aid of a one or two anchors system. Evaluation of embodied energy (EE) and CO2 emissions for each of the wall designs and anchoring systems were compared. Results show that there are notable differences in EE between different wall designs. Using the averaged set of Embodied Energy Intensity (EEI) values, the use of recycled steel over virgin steel would reduce the EE of the wall significantly. The difference in anchor designs is relatively insignificant, and therefore the practicality of the design for the specific site should be the deciding factor for anchor types. Generally, the scale of environmental impacts due to constructions is large compared to other aspects in life as demonstrated with the comparisons to car emissions and household energy consumption. Copyright ASCE 2008.

Environmental evaluation of localising production as a strategy for sustainable development: a case study of two consumer goods in Jamaica

The objective of this study was to compare the life-cycle environmental impacts of changed production structures for two consumer goods (high-density polyethylene (HDPE) shopping bags and beds) in Jamaica. A scenario technique was used to construct three alternative production structures for each product; each scenario reflecting an increase in local production in Jamaica which depended on an increased supply of input materials which may be sourced: (1) externally from overseas suppliers, (2) from post-consumer recycling, and (3) locally on the island of Jamaica. These three constructed scenarios were then compared to the existing supply chain or reference scenarios of the products. The results showed that for both case products the recycling scenario was most preferable for localising production, resulting in the lowest environmental impact. This was because the production of raw materials accounted for the largest effect on total environmental impact. As such, the most immediate environmental improvements were realised by lowering the production of virgin materials. © 2007 Elsevier Ltd. All rights reserved.

Embodied energy and gas emission of geotechnical infrastructure

Construction of geotechnical structures produces various environmental impacts. These include depletion of limited natural resources, generation of wastes and harmful substances during material productions and construction, ineffective usage of energy during processing of raw materials into construction materials, and emissions of unwanted gasses during transportation of materials and usage of equipments. With increasing interests in sustainability at the global scale, there is a need to develop a methodology that can assess environmental impacts at such scale for geotechnical construction. Using embodied energy and gas emission, quantitative measures of environmental impact are evaluated using a case study of a new high speed railway line construction in the UK. Based on the results, the keys to energy savings are (a) to optimise the usage of materials with high embodied energy intensity value (b) to optimise the transportation network and logistics for processes using primarily low embodied energy intensity materials and (c) to reuse as much materials on-site as possible to minimise the quantity of spoils or distance to disposal sites. The evaluated embodied energy and embodied carbon values are compared to those of other types of structures and of other activities and carbon tax values. Such comparisons can be used to discuss among various interested parties (clients, contractors, consultants, policy makers, etc) to make the construction industry more energy efficient. © Springer Science+Business Media B.V. 2011.

Polymer film packaging for food: An environmental assessment

Plastics packaging is ubiquitous in the food industry, fulfilling a range of functions including a significant role in reducing food waste. The public perception of packaging, however, is dominated by end-of-life aspects, when the packaging becomes waste often found littering urban, rural and marine environments. A balanced analysis of the role of packaging demands that the whole lifecycle is examined, looking not only at the packaging itself but also at the product being packaged. This paper focuses on packaging in the meat and cheese industry, analysing the impact of films and bags. The functions of packaging are defined and the environmental impact of delivering these functions is assessed. The influence of packaging on levels of waste and energy consumption elsewhere in the system is examined, including the contentious issue of end-of-life for packaging. Strategies for minimizing the environmental impact of the packaging itself involve reduction in the amount of material used (thinner packaging), rather than emphasizing end-of-life issues. Currently, with polymer recycling not at a high level, evidence suggests that this strategy is justifiable. Biodegradable polymers may have some potential for improving environmental performance, but are still problematic. The conclusion is that although current packaging is in some ways wasteful and inefficient, the alternatives are even less desirable. © 2013 Elsevier B.V. All rights reserved.