• Energy Research
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The main challenge for concrete industry - and in general for construction materials - is to serve the two major needs of human society, the protection of the environment, on one hand, and the requirements of buildings and infrastructures by the world?s growing population, on the other. In the past concrete industry has satisfied these needs well. However, for a variety of reasons, the situation has changed dramatically in the last years. First of all, the concrete industry is the largest consumer of natural resources. Secondly, Portland cement, the binder of modern concrete mixtures, is not as environmentally friendly. The world's cement production, in fact, contributes to the earth's atmosphere about 7% of the total CO2 emissions, CO2 being one of the primary greenhouse gas (GHG) responsible for global warming and climate change. As a consequence, concrete industry in the future has to face two antithetically needs. In other words, how the concrete industry can feed the growing population needs being - at the same time - sustainable? The answer to this question is represented by the ?3R-Green Strategy? widely discussed in the first chapter of this PhD thesis: Reduction in consumption of gross energy for construction materials production, Reduction in polluting emissions and Reduction in consuming not renewable natural resources. In particular, this thesis is focused on the alternative binders to Portland cement such as alkali-activated slag cements and calcium sulphoaluminate cement-based binders in order to manufacture sustainable mixtures for special applications such as repair mortars, lightweight reinforced plasters and concretes for slabs on ground. The experimental results show the feasibility of manufacturing both EN 1504-3 R3 class mortars and Portland-free concretes for jointless slabs on ground with calcium sulphoaluminate cement, supplementary cementitious materials (fly ash, ground granulated blast furnace slag) and hydrated lime instead of Portland cement. Moreover, alkali-activated mortars and concretes seem to be a reasonable alternative to natural hydraulic lime-based and/or traditional Portland cement-based mixtures for rehabilitation or restoration of ancient masonry buildings and existing concretes structures. Finally, a new sustainability index was developed taking into account the environmental impact, the performances and the durability of mixtures. In particular, in the environmental impact section, the natural raw materials consumption, the greenhouse gas emissions and the energy consumption have been considered. Furthermore, depending on the applications and the environments, design parameters and properties related to durability have been assigned to each mixture. less

This review presents “a state of the art” report on sustainability in construction materials. The authors propose different solutions to make the concrete industry more environmentally friendly in order to reduce greenhouse gases emissions and consumption of non-renewable resources. Part 1—the present paper—focuses on the use of binders alternative to Portland cement, including sulfoaluminate cements, alkali-activated materials, and geopolymers. Part 2 will be dedicated to traditional Portland-free binders and waste management and recycling in mortar and concrete production.

AbstractAn Eco-Design methodology based on two abridged Life Cycle Assessment tools (eVerdEE [1] developed by ENEA [2] and the French Standard NF 01-005) plus TRIZ [3] Eco-guidelines is presented. This method is one of the outputs of the European project REMake [4] (started September 2009 ended December 2012), which had the goal of developing and testing new approaches for eco-innovation, recycling and material consumption for manufacturing small and medium sized enterprises (SMEs). The number of SMEs involved in the project has been around 250, in six countries.The proposed method consists of a preliminary scanning of a given product or process in order to disclose all the material involved and the energy flows, and to assess their environmental impact by means of a simplified Life Cycle Assessment (LCA) approach and the related indexes. The “hot spots” of the product or process are then identified by adding a brand new index called “IFR (Ideal Final Result) index”, conceived from the TRIZ “Ideal System” concept [5], to classical LCA criteria.Once the hot points are identified, a set of over 300 TRIZ based eco-design guidelines [6,7] are selectively introduced to develop design variants to the given system with the aim of providing a lower global environmental impact. An in-depth explanation about ECO guideline implementation is given, together with a case study concerning a manufacturer of machine tools.

Abstract This work presents the measured performance data related to the very-first Energy+ building in Dubai certified by the Passive House Institute. The building is a two-floor office structure, with 550 m2 total surface, designed under the guide and the scientific supervision of a Bergamo University research group, jointly to the Mohammed Bin Rashid Space Centre (MBRSC). The goal of the project was to assure a high level of internal comfort all over the year by using only solar energy. The building architecture has been designed to minimize the cooling load and the energy demand. The energy system is based on a 40 kWp PV field coupled with a 48 kWh electric storage and a high-efficiency chiller (reversible heat pump). Transient simulations by Trnsys code have been carried out to optimize both the thermal envelope and the energy plants so to make the building energy-autonomous 24/7. The numerical predictions of the energy performance (including cooling load, PV production and power consumption for chiller, lighting and appliances) are compared to the real data measured by a sophisticated monitoring system, including sensors located in the roof, in the external walls and in the energy systems. The field measurements confirm that the model predictions were accurate both in terms of peak and annual values. The small variations between prediction and real data show that both thermal envelope and PV field perform better than expected. This building is a pioneering pilot-project: the goal was to show that new sustainable construction standards using only solar energy are possible in the United Arab Emirates (UAE) and that this is a viable solution to reduce the carbon footprint in all the Gulf region. The strategic importance of an accurate modeling activity leading to an optimal design has been proved. The monitored data under real operating conditions have confirmed that the expected targets in terms of energy savings and carbon footprint reduction have been successfully achieved.

AbstractSoil sealing processes that involved European cities in the twentieth century have reduced the quantity and quality of permeable soils (open land for agricultural and leisure resources). These processes have also weakened the ability of urban areas to manage natural events, of all evidence regarding the water cycle. This intense phase was supported by a cycle of growth that showed signs of an irreversible crisis only in the last decade, starting a new and unprecedented season. However, soil sealing development constitutes the most intense form of land degradation and affects all ecosystem services (Tobias et al. in Land Degrad 29:2015–2024, 2018). This is particularly true for spaces and territories along main rivers where the presence of sealed areas and concrete channels (riverbed and riverbanks) represents a problem regarding hydrogeological, ecological, and landscaping aspects. To safeguard urban systems, by restoring “landscape river” (and its surroundings), increasing green areas and more efficient management of the rainwater, it is fundamental to enhance the “removing sealing layers” (EU 2012) according to a holistic approach. This paper explores the de-sealing concept and highlights some international and Italian cases, in particular the River Contracts experience promoted in the Lombardy Region, including actions proposed by public policies and urban planning tools. All these experiences have proposed de-sealing processes of river environments and urban systems ensuring a new integration between urban areas and “water landscapes”. To underline some characteristics this exploration allowed: to highlight different de-sealing approaches, between direct or indirect conditioning; to recognize river elements and “environments” in which these initiatives are activated; to recognize in these initiatives a multi-scale attitude both the expected effects and the type of involved institutional subject involved; to identify the main subjects, with specific roles and responsibilities, in this type of process; to recognize limits and critical issues. River restoration, combined with de-sealing actions inside the urban structures, shall be performed by answering to several needs: increasing the green open space quantity and ecosystem services recovery; contributing to biodiversity by restoring ecosystems and ecological processes; balancing the soil-sealing negative externalities; improving the flood-risk mitigation and management in urban areas. In particular, the voluntary instrument of the River Contract includes a territorial area that is adequate for the treatment of the phenomenon but is struggling to be codified in the local planning instruments with cogency. The assumption of different spaces and the recognition of the same in the spatial devices of urban planning instruments could define more clearly the need to face the water-city relationship effectively, for the benefit of urban security and the quality of the inhabitants’ living environment.

Abstract Approximately 40% of the European energy consumption and a large proportion of environmental impacts are related to the building sector. However, the selection of adequate and correct designs can provide considerable energy savings and reduce environmental impacts. To achieve this objective, a simultaneous energy and environmental assessment of a building's life cycle is necessary. To date, the resolution of this complex problem is entrusted to numerous software and calculation algorithms that are often complex to use. They involve long diagnosis phases and are characterised by the lack of a common language. Despite the efforts by the scientific community in the building sector, there is no simple and reliable tool that simultaneously solves the energy and environmental balance of buildings. In this work, the authors address this challenge by proposing the application of an Artificial Neural Network. Due to the high reliability of learning algorithms in the resolution of complex and non-linear problems, it was possible to simultaneously solve two different but strongly dependent aspects after a deep training phase. In previous researches, the authors applied several topologies of neural networks, which were trained on a large and representative database and developed for the Italian building stock. The database, characterised by several building models simulated in different climatic conditions, collects 29 inputs (13 energy data and 16 environmental data) and provides 7 outputs, 1 for heating energy demand and 6 of the most used indicators in life cycle assessment of buildings. A statistical analysis of the results confirmed that the proposed method is appropriate to achieve the goal of the study. The best artificial neural network for each output presented low Root Mean Square Error, Mean Absolute Error lower than 5%, and determination coefficient close to 1. The excellent results confirmed that this methodology can be extended in any context and to any condition (other countries and building stocks). Furthermore, the implementation of this solution algorithm in a software program can enable the development of a suitable decision support tool, which is simple, reliable, and easy to use even for a non-expert user. The possibility to use an instrument to predict a building's performance in its design and planning phase, represent an important result to support decision-making processes toward more sustainable choices.

The main goal of this paper is to assess the life cycle environmental impacts of a multifunctional smart window luminescent solar concentrator (SW–LSC) prototype through the application of the Life Cycle Assessment methodology. To the authors’ knowledge, this is one of the first studies on the topic. The analysis followed a cradle to gate approach, considering the assembly and maintenance phase as well as the end of life, examined separately through a recycling/landfill scenario. A comparison of the impacts of LSC modules with those of some building-integrated photovoltaic technologies was carried out. Results showed that the global warming potential (100 years) for SW–LSC was 5.91 × 103 kg CO2eq and the manufacturing phase had the greatest impact (about 96%). The recycling/landfill scenario results showed the possibility to reduce impacts by an average of 45%. A dominance analysis of SW–LSC components showed that the aluminum frame was the main hotspot (about 60% contribution), followed by the light-shelf (about 19%). Batteries and motors for the shading system were the biggest contributors in the abiotic depletion potential category (36% and 30%, respectively). An alternative scenario, which involved the use of 75% recycled aluminum for the window frame, highlighted the possibility to reduce environmental impacts from 3% to 46%. Finally, the comparison results showed that the LSC modules’ impacts were on average 870% lower than that of various PV technologies when compared on the basis of m2; on the contrary, LSC modules had the highest impacts in all categories (from 200% to 1900%) when compared with other PV technologies on the basis of 1 kWh of energy generated. The results could be used for the definition of eco-design strategies for the examined device, in order to support the scaling-up process and to put “greener” systems onto the market.