Sustainability of Modular Lightweight Steel Building from Design to Construction

The increasing concerns over population growth, depletion of natural resources and global warming as well as catastrophic natural events is leading the international scientific community to envisage sustainability as a crucial goal. The built environment plays a key role on the triple bottom line of the sustainable development -- Planet, People, Profit -- because of several environmental, social and economic impacts produced by the construction sector. The acknowledged need to promote a sustainable building market is an international high-priority issue as underlined by the 2030 Agenda for Sustainable Development. Indeed one of its strategic objectives highlights to make cities and human settlement inclusive, safe, resilient and sustainable. In line with the 2020 Europe Strategy and the European 2050 Roadmap, energy efficiency and CO2 savings towards a low-carbon economy are regarded as ambitious objectives to be achieved for both new and existing buildings. Thus, controlling and reducing the environmental impacts of new constructions is fundamental. In line with this, the “Energy efficient LIghtweight Sustainable SAfe steel construction” (ELISSA) research project financed under the European FP7 aimed to develop a modular Cold-formed steel system that is energy efficient and robust. This paper presents the life cycle analysis of the building developed as case demonstrator. It analyses the environmental impacts during both the construction and the deconstruction phase. This works provides a benchmark of the current possibilities offered by lightweight steel structures in the framework of sustainable constructions

Life Cycle Assessment in construction industry: applications to structural materials and components.

Material, energy, water use and occupation land related to construction industry activities represent a major contribution to the total environmental impact caused by society. In fact, it is estimated that the building sector is responsible for the 30–40% of the society’s total energy demand and approximately 44% of the total material use. Consequently, the building sector has to be prioritized to be able to reach a sustainable society within a reasonable period of time. The present work is included in the context of the assessment of sustainability of construction sector and is aimed at analyzing and quantifying the environmental impact of its related activities at different levels of analysis of the building industry. In detail, the environmental performance is performed by means of a Life Cycle-oriented approach. Two main approaches of Life Cycle Assessment (LCA) for construction applications have been considered: i) LCA for Building Materials and Component Combinations (BMCC), i.e. focusing on building materials, and ii) LCA of the Whole Process of the Construction (WPC), i.e. considering entire building system or sub assemblages. The approach i) has been applied to evaluate the environmental footprint of recycled and natural concretes. The main purpose has been the computation of the environmental impact of the conventional and innovative building materials in order to quantify the potential environmental benefits (e.g. in terms of CO2 emissions, raw material usage, waste recycling etc) of new (innovative) solutions. LCA has been also implemented to evaluate the environmental profile of different retrofit solutions on existing buildings, using approach ii). This work has investigated possible design alternatives for retrofit/renovation operations when structural/functional requirements have to be fulfilled. In detail, the environmental impact of different design options for a typical structural retrofit operation conducted on masonry and reinforced concrete buildings have been assessed. The scope of this thesis is to illustrate several comprehensive LCA-based approaches that could be effectively used to drive the design of new and existing buildings. The final objective of this contribution is to show how a rigorous environmental analysis can influence decision-making in the definition of the most sustainable design alternatives. The designers can monitor the environmental impact of different design strategies in order to identify the most suitable option

Sustainability of modular lightweight steel building from design to deconstruction

The increasing concerns over population growth, depletion of natural resources and global warming as well as catastrophic natural events is leading the international scientific community to envisage sustainability as a crucial goal. The built environment plays a key role on the triple bottom line of the sustainable development - Planet, People, Profit - because of several environmental, social and economic impacts produced by the construction sector. The acknowledged need to promote a sustainable building market is an international high-priority issue as underlined by the 2030 Agenda for Sustainable Development. Indeed one of its strategic objectives highlights to make cities and human settlement inclusive, safe, resilient and sustainable. In line with the 2020 Europe Strategy and the European 2050 Roadmap, energy efficiency and CO 2 savings towards a low-carbon economy are regarded as ambitious objectives to be achieved for both new and existing buildings. Thus, controlling and reducing the environmental impacts of new constructions is fundamental. In line with this, the “Energy efficient LIghtweight Sustainable SAfe steel construction” (ELISSA) research project financed under the European FP7 aimed to develop a modular Cold - formed steel system that is energy efficient and robust. This paper presents the life cycle analysis of the building developed as case demonstrator. It analyses the environmental impacts during both the construction and the deconstruction phase. This works provides a benchmark of the current possibilities offered by lightweight steel structures in the framework of sustainable constructions

LCA-based study on structural retrofit options for masonry buildings

Purpose: Over the last decade, the rehabilitation/renovation of existing buildings has increasingly attracted the attention of scientific community. Many studies focus intensely on the mechanical and energy performance of retrofitted/renovated existing structures, while few works address the environmental impact of such operations. In the present study, the environmental impact of typical retrofit operations, referred to masonry structures, is assessed. In particular, four different structural options are investigated: local replacement of damaged masonry, mortar injection, steel chain installation, and grid-reinforced mortar application. Each different option is analyzed with reference to proper normalized quantities. Thus, the results of this analysis can be used to compute the environmental impact of real large-scale retrofit operations, once the amount/extension of them is defined in the design stage. The final purpose is to give to designers the opportunity to monitor the environmental impact of different retrofit strategies and, once structural requirements are satisfied, identify for each real case the most suitable retrofit option. Methods: The environmental impact of the structural retrofit options is assessed by means of a life-cycle assessment (LCA) approach. A cradle to grave system boundary is considered for each retrofit process. The results of the environmental analysis are presented according to the data format of the Environmental Product Declaration (EPD) standard. Indeed, the environmental outcomes are expressed through six impact categories: global warming, ozone depletion, eutrophication, acidification, photochemical oxidation, and nonrenewable energy. Results and discussion: For each retrofit option, the interpretation analysis is conducted in order to define which element, material, or process mainly influenced the LCA results. In addition, the results revealed that the recycling of waste materials provides environmental benefits in all the categories of the LCA outcomes. It is also pointed out that a comparison between the four investigated options would be meaningful only once the exact amount of each operation is defined for a specific retrofit case. Conclusions: This paper provides a systematic approach and environmental data to drive the selection and identification of structural retrofit options for existing buildings, in terms of sustainability performance. The final aim of this work is also to provide researchers and practitioners, with a better understanding of the sustainability aspects of retrofit operations. In fact, the environmental impacts of the retrofit options here investigated can be used for future research/practical activities, to monitor and control the environmental impact of structural retrofit operations of existing masonry buildings

Life cycle environmental impact of different replacement options for a typical old flat roof

Purpose: Numerous strategies have been implemented to reduce the global environmental burden of construction activities in order to achieve sustainable development goals. However, with regard to renovating and retrofitting existing buildings, life cycle assessment (LCA)-based studies mostly focus on the improvement of a building’s energy performance rather than on the structural aspects of the retrofit itself. The present study assesses the life cycle environmental impacts of different replacement options for a typical old flat roof belonging to a masonry building. Three different structural options are considered: reinforced concrete joists and hollow clay blocks, steel joists and concrete slab, and reinforced concrete joists and polystyrene panels. Methods: The environmental analysis is based on a new approach wherein the structural and functional properties of a new flat roof are set as fixed requirements for the design of the different replacement options. A cradle-to-grave LCA-based study is then conducted for the environmental assessment of the entire retrofit process, including different waste scenarios. SimaPro software and IMPACT2002+ methodology are used for the LCA analysis, enabling quantification of the environmental impacts of the three flat roofing options by means of 4 endpoint and 15 midpoint indicators. Results and discussion: The environmental contribution of each life cycle phase related to the replacement of the old flat roof is assessed. The results demonstrate that within the life cycle of each option, the use phase and the construction phase have the highest environmental impact, ranging from 60 to 70 % and 50 to 80 % of the total burden in the Climate Change/Resources and Human Health/Ecosystem Quality damage categories, respectively. Having initially set structural and functional constraints for the analysis, the results show that any of the different options exhibits an overall lowest environmental performance. Consequently, specific environmental burdens/categories can be identified to optimize the sustainable retrofit design. Conclusions and recommendations: The work demonstrates that a comprehensive LCA-based approach can be used to effectively drive the design of structural and functional retrofit operations on existing buildings. This study also shows how a rigorous environmental analysis, conducted by implementing the proposed approach, can influence decision-making for the most sustainable design alternatives. © 2015, Springer-Verlag Berlin Heidelberg

Environmental impact of the replacement of an existing wooden floor

The life cycle assessment (LCA) methodology can be used as a decision-making tool in the sustainable design and construction of buildings. However, there are not many stud ies investigating the use of LCA to compare alternative retrofit interventions on existing struct ures. The objective of the present st udy is to analyze the environmental impact of different replacement options for a typical old wooden roof in an existing building. Th e flooring options have been designed to achieve the same structural performance in terms of load bearing capacity

Preliminary remarks on the environmental impact of ordinary and geopolymer concrete

Concrete is one of the most commonly used among construction materials. Generally, concrete is produced by using Ordinary Portland Cement (OPC) as binder and it contributes conservatively to 5 - 8% of global anthropogenic CO2 emissions. New low - CO2 binders are therefore needed to satisfy the demand for concrete. The objective of the present study is to perform a detailed environmental impact analysis of standard geopolymer concrete and compare it with OPC concret

Environmental life cycle assessment of lightweight concrete to support recycled materials selection for sustainable design

The constant increase in consumption of aggregates for concrete production represents a major environmental issue in the construction industry. Recycled wastes might be used as raw materials in the manufacturing of artificial LightWeight Aggregates (LWAs) in substitution and/or in combination with aggregates produced using natural sources for several end-uses, thus saving non-renewable resources. In this study, a Life Cycle Assessment (LCA) is performed for different LWAs manufactured with raw materials supplied by nature or waste. Then, the LCA is conducted on different concretes made of the different LWAs