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The design of building foundations has usually been based on tradition, local practice, experience, and structural design codes. Safety is invariably considered the main factor and environmental criteria (or, in general, sustainability) is seldom given due consideration. However, similar safety indicators can be achieved with different variables and a minimum safety factor must always be ensured. The main objective of this study is, from an environmental perspective, to assess the influence of the construction system (cast-in-situ or precast), foundation type (rigid or flexible), and structural code (EC-2 or EHE-08) in the case of a concrete shallow foundation (CSF), using Life Cycle Assessment (LCA). Applying this methodology, the materials (concrete and steel) yielded the highest impacts in all categories, at around 95% for cast-in-situ CSFs and at around 85% for precast CSFs, both in relation to global warming. Consequently, optimization of the amount of these materials is crucial when considering the particular variables selected in this study. The results showed that cast-in-situ and flexible CSFs at moderately shallow depths (and therefore with less steel reinforcement) and precast CSFs with considerable reductions in concrete volumes (due to sloped shapes) had lower environmental impacts. In addition, cast-in-situ CSFs constructed in accordance with the EHE-08 structural code showed lower impacts, while precast CSFs complying with the EC-2 code were environmentally preferable. However, a specific study might be required for specific factors in each case (loads, soil type, structural settlement, among others). Relevant environmental effects associated with the three variables should therefore be given specific consideration in the development of structural design codes and future constructions. [ABSTRACT FROM AUTHOR]

Stormwater management is essential to reducing the occurrence of flooding events in urban areas and to adapting to climate change. The construction of stormwater Best Management Practices (BMPs) entails a series of life cycle environmental impacts but also implies avoided burdens, such as replacing urban infrastructure after flooding. The aim of this paper is to integrate flood damage prevention into the life cycle assessment (LCA) of BMPs for quantifying their net environmental impact (NEI) and environmental payback (EP) from a consequential LCA standpoint. As a case study, the application of a filter, swale and infiltration trench (FST) in a Brazilian neighborhood was assessed considering a high-intensity rainfall event. The potential avoided impacts were related to cars and sidewalks that were not destroyed due to flooding. In terms of CO 2 eq. emissions, the environmental investment related to the FST was recovered when the destruction of one car or 84 m 2 of sidewalk was prevented. The NEI of the FSTs resulted in significant impact reductions (up to 700%) with respect to not accounting for the avoided products. This approach can be implemented to any type of BMP, and more accurate estimations can be made with data for different events and different types of material damage. [ABSTRACT FROM AUTHOR]

Abstract: Until now, few studies had focused on the environmental impact of the construction phase of a drinking water transport and distribution network (DWTDN). Using the life cycle assessment (LCA) methodology, this article compares the environmental impact of pipes made of different materials as constructive solutions for the DWTDN. Two pipe diameters (90 and 200 mm) commonly used in small to medium-sized cities are analysed. The results show that polyvinyl chloride (PVC), high density polyethylene (HDPE) and low density PE have similar environmental impacts in the case of 90 mm pipe diameter. In the case of 200 mm pipe diameter, ductile iron (DI) and glass fibre reinforced polyester show higher environmental impacts than HDPE and PVC, which in the case of DI are between 3 and 11 times higher than those of HDPE for all the midpoint impact categories. Regarding the different construction phases, installation has a higher percentage of environmental impact for 90 mm pipe diameter (40–68% for HDPE in all the impact categories) than for 200 mm pipe diameter (24–57% for an HDPE) due to the difference in the amount of material required for the manufacture of the pipe. The assessment methodology was applied to calculate the environmental burdens derived from a case study. The impact of the different elements of the case study network has been added to obtain the global impact. The potential reduction of the environmental impacts of the case study has been calculated substituting the whole actual network by less impacting constructive solutions. A potential reduction of between 6 and 16% of the impact has been found for the case study, although the savings might be greater in networks with greater abundance of more impacting pipe materials such as DI. This methodology allows the improvement of the network and the design of more eco-efficient DWTDN. [Copyright &y& Elsevier]

Abstract: A life cycle assessment to evaluate the environmental impact of urban sewage sludge use as alternative fuel or raw material in clinker production was carried out. In order to quantify in detail the overall environmental impact of both scenarios, the sewage sludge treatment process and the transport to cement facilities for both alternatives were considered. The substitution ratio of fuel (petcoke) and raw material (limestone) was fixed between 5 and 15% according to the cement production plant limitations. Both scenarios show CO2 savings when compared to the clinker production without substitution. The mid-point and end-point analysis were favourable to the fuel substitution with savings ranging from 3 to 7% compared to the raw material substitution and also to base case without substitution. The influence of the amount of sewage sludge used for both scenarios indicates that fuel substitution reduced the CO2 emissions when the amount of substitution is increased, while other mid-point and end-point categories were proportionally favourable to the fuel substitution scenario. Additionally, the influence of the substituted material characteristics showed that low heating value (fuel substitution) and CaO addition in lime stabilized sludge (raw material substitution) are critical parameters in terms of environmental impact in clinker production. The fuel substitution represents a significant environmental improvement compared to the raw material substitution scenario and clinker production without substitution. [Copyright &y& Elsevier]

Abstract: A cement manufacturing company located in Catalonia (Spain) has upgraded its cement production plant. The new cement production line (L6) has replaced the former lines (L3, L4 and L5) which have been operating for 30 years. The new line production L6 has been designed and constructed taking into account the best available techniques (BAT) for the cement industry. The significant improvements achieved with the new plant are related to the energy efficiency of the new kiln system which represents less amount of fossil fuel and to less emission to the atmosphere per kg of clinker produced. Life-cycle assessment (LCA) methodology has been used for the quantification and evaluation of the environmental impacts of the new production line (L6) considering the designed goals proposed and those achieved at first trimester of 2011 compared to the former production lines. To reduce uncertainty this manuscript presents a cradle-to-gate life-cycle assessment of both scenarios. Analysis using SimaPro 7.2 software shows that new production line (L6) provides a significant reduction of the environmental impact for global warming (5%), acidification (15%), eutrophication (17%) and cumulative exergy demand (13%). The damage assessment also confirmed that new production line (L6) reported a significant reduction impact for the human health (11%), ecosystem quality (11%) and resources (14%) damage compared to the former lines. [Copyright &y& Elsevier]