bluuebunny/crossref_metadata_2025_split huggingface dataset:
Modification on Recycled Aggregates and its Influence on Recycled Concrete
Authors: Huang K , Ding T , Xiao J , Singh A 
Published: September 2019

Abstract
Recycled aggregates produced from waste concrete are widely accepted as green building material. However, demolition processes will bring recycled aggregates with a lower apparent density, bulk density whereas a higher porosity, silt content, water absorption, crushing index value when compared with natural aggregates. So the strengthening and modification of recycled aggregates have become a prominent technological issue in the producing process.
This paper introduces current modification methods on the recycled aggregates, which mainly include: (1) physical technology, its basic idea is to remove the waste cement paste adhered to recycled aggregates, such processions as rubbing, heating, particle shaping, and micro-heating; (2) chemical technology, carried out by immersing recycled aggregates in different kinds of chemical grout, which can be mixed with additive Kim powder, silica fume, fly ash, and any other fine mineral powder or slag; (3) carbonation technology, when newly collected crushed aggregates are put into atmosphere with high CO2 concentration, the adhesive cement paste can react with CO2 and produce CaCO3 that will precipitate in the capillary pores or cracks, which will improve properties of recycled aggregates; (4) nano technology, the use of nanomaterials can promote the hydration reaction, react with cement based materials, fill pores and control the process of crystallization. Conclusions are put forward and several problems concerning modification need to be considered for further research and application are proposed and discussed. Compared with natural concrete, RAC is superior to environmental value in the reduction of CO2 emission in Life Cycle Assessment.
Parametric life cycle assessment of a reusable brick veneer
Authors: Vandervaeren C , Galle W , De Temmerman N 
Published: September 2019

Abstract
A possible design strategy to improve the sustainability of building products is facilitating their future reuse. This strategy inspires some manufacturers to design innovative products, such as reusable façade products. Although these products might have a higher environmental impact for production, their reusability could lead to an environmental saving from a life cycle perspective. A possible method to evaluate their environmental performance is life cycle assessment (LCA). Nevertheless, LCA studies of reusable products are still rare. Furthermore, although the general LCA frameworks is fixed by ISO and CEN standards, some methodological choices must still be made by LCA practitioners. This paper first presents a method (as four methodological choices) for a parametric life cycle assessment of reusable building elements. Then, this method is applied to a comparative LCA of reusable and brick-and-mortar veneers. With proposed method, the reusable brick veneer is environmentally advantageous if it is reused at least once and if it is properly recycled at its end-of-life. The parametric method also indicates the relative influence of various parameters such as reuse rate, number of interventions, transport distances and waste treatment. The manufacturers can use this LCA study as a retrospective assessment to validate the relevance of design choices, but also as target-driven product management support to know hot-spots in the product’ life cycle management. This study will hopefully inspire other designers and manufacturers and accelerate the transition towards a sustainable built environment.
Butt-joint bonding of timber as a key technology for point-supported, biaxial load bearing flat slabs made of cross-laminated timber
Authors: Zoellig S , Muster M , Themessl A 
Published: September 2019

Abstract
An efficient butt-joint bonding technology allows to build new types of timber structures. Under the name Timber Structures 3.0 a connection has been developed which connects timber elements with an end-grain to end-grain butt joint bonding. Therefore, it is now possible to build continuous, point supported flat slabs in cross laminated timber (CLT). Multiple CLT slabs are connected rigidly together and are only supported by columns. Some major challenges had to be solved in terms of bending strength of the glued connection and shear resistance of the part of the slab above the column. The research in both topics is successful and more projects were built in the last two years using this technology. Starting point was a real scale structure at ETH Zurich, followed by a working platform for a timber construction company and finally four three storey residential buildings. The research team is continuing to optimize the different elements of this innovative technology and will soon provide engineers with guidelines to design their own biaxial, point supported timber flat slabs.
Environmental Product Declarations (EPDs) as a competitive parameter within sustainable buildings and building materials
Authors: Andersen S C , Larsen H F , Raffnsøe L , Melvang C 
Published: September 2019

Abstract
The demand for technical and verified documentation of buildings and building materials is growing, along with the increasing focus on sustainability in the built environment. However, despite a common wish to build sustainably, it is still found that EPDs and LCAs are not always similarly interpreted, leading to misunderstandings on how they should be used to quantify and verify sustainability along with being a competitive parameter when choosing materials.
To overcome this barrier this project seeks to discover:
1. How can EPDs be used as a competitive parameter within the sustainable built environment?
2. How can product specific EPDs, used as an input to building-level LCAs, help to quantify the concept of ‘circular economy’?
3. How do some countries seem to succeed in introducing EPDs to industry while others only succeed to a lesser extent?
By involving the Danish building-industry’s value-chain through qualitative interviews, workshops and reference groups, as well as by contacting EPD programme operators throughout Europe and USA, a mapping has been performed on the tendencies of how and to what extend EPDs are used to quantify and support material decision-making in buildings. Further, the drivers as to why EPDs are used in some countries is investigated along with suggestions on how to boost the development, use and integration of EPDs with the aim of quantifying and documenting sustainability in the built environment.
Roles of the reference service life (RSL) of buildings and the RSL of building components in the environmental impacts of buildings
Authors: Potrč Obrecht T , Kunič R , Jordan S , Legat A 
Published: September 2019

Abstract
The Life Cycle Assessment of a building is a complex analysis that also involves the use of the predicted Reference Service Life (RSL) of the building components and materials, as well as the predicted RSL of the whole building. The RSL values of individual materials and building components can be obtained from different sources and are not exactly comparable. In the present study, the influence of selected RLS values on an LCA assessment was evaluated. Three different RSL databases were used as the sources of the data to estimate the environmental impacts of selected building components (internal wooden door and external finishing coat). Two scenarios were presented. In the first scenario a building component can be reused in another building, while in the second scenario the reuse of the building component is not possible. The study showed that dependent on the selected RSL database, the results can differ by up to a factor of five. Therefore, it is very important to describe clearly the maintenance scenarios for a building in order to have a reliable comparison of the results of LCA assessments.
Economic valuation of life cycle environmental impacts of construction products - A critical analysis
Authors: Durão V , Silvestre J D , Mateus R , De Brito J 
Published: September 2019

Abstract
The aim of this paper is to identify existing methods for economic valuation or monetisation of life cycle environmental impacts and to assess its applicability in the broad European context. Although environmental awareness is more and more important in several industrial sectors, including the construction sector, easy to understand data are still missing for professionals to assess and manage impacts related to the whole life cycle of a building. Life Cycle Assessment (LCA) is one of the most commonly accepted methodologies to calculate potential life cycle environmental impacts of a product or service. However, the results of such method, even when published in an Environmental Product Declaration, meant for business to business communication, are not always comparable or easily understandable by non-practitioners. Economic valuation or monetisation of LCA results is a weighting step that can make it easier for non-practitioners to use LCA results to support decision-making. From the several monetisation methods analysed, it is discussed the one that is most suitable for use when LCA results already exist. It is concluded that further work is needed to improve such weighting methods or develop a common one that can be representative at a broader geographical level (for instance, Europe-wide).
Partially dynamic life cycle assessment of windows indicates potential thermal over-optimization
Authors: Horup L , Reymann M , Rørbech JT , Ryberg M , Birkved M 
Published: September 2019

Abstract
To reach the environmental goals set by EU, Energy Performance of Buildings Directive (EPBD) and national building regulations will demand reductions in building’s energy consumption. Energy consumption goals for buildings are pursued through high thermal performance building components (HTPBC). Paradoxically, building regulations have no requirements regarding the embodied energy of buildings and components. To meet the requirements set by governments, HTPBCs in most cases require an increasing embodied energy (from insulation), assumed to be paid back during the service-life of HTPBCs. Accounting for decarbonization of the future energy supply, the expected payback might not be feasible in terms of total environmental footprint, since the future energy supplies are expected to be greener than the building’s embodied energy. Using roof windows as a case study, we assess if strict demands for building’s energy consumption, will lead to more sustainable buildings if all temporal variations in terms of global warming impacts across the service-life are taken into account. A comparison of double and tripple glazed windows reveals that the expected net energy savings obtained during the use phase are compromised by relatively higher impacts induced in the production stage. The case study indicates requirements of building’s energy performance might compromise the overall sustainability of building component solutions, as the additional embodied energy required to produce triple glazed windows most likely will not be compensated for by saved operational energy, when taking into account the forecasted decarbonatization of the building energy future supply.
Lifecycle analysis of finishing products enhanced with phase changing materials
Authors: Zhuk Petr 
Published: September 2019

Abstract
Applicability of phase changing materials (PCMs) in buildings by their integration into the structure of finishing materials structure in the form of particles is especially high as a mean of providing heat-insulation during summer. Materials containing particles with phase changing behaviour are successfully applied at objects with large daylight areas, focused on active utilization of sunlight energy, among others. Utilization of PCM components allows saving considerable amount of energy due to possible refusal of air-conditioning while providing heat-insulation during summer.
The paper deals with the lifecycle analysis of gypsum-based finishing products. Main challenges with respect to the lifecycle of products with PCM components are the preservation of their longevity as well as their potential for reuse/recycling. Through the example of PCM-enhanced plaster covering and gypsum plasterboard factors affecting the preservation of the advantageous thermal properties of PCMs over extended periods were studied, along with options of refining materials and products containing different amounts of PCM components.
The results of the research allow comparing similar materials with the use of PCM components and without them as well as analyzing the life cycle related environmental performance of PCM-enhanced finishing materials.
Designing a smart factory for mass retrofit of houses
Authors: Lange K , Kraemer U-B 
Published: September 2019

Abstract
The North Sea Region (NSR) contains 22 million houses built in 1950-1985 that cause 79 Mton CO2 emissions annually. Current deep retrofit home renovations are carried out on a limited-scale production and only in small projects. This results in the problem that nowadays renovation costs are way too high and the pace of renovation is far too low. Large scale renovations of existing homes towards energy-neutral are currently not addressed in the North Sea Region. Still, the retrofit of houses in the North Sea Region is essential to reach the European energy and climate objectives. However, the building sector in Europe is not creating the necessary production facilities. The target of the just started INTERREG project INDU-ZERO is to develop a blueprint for a production facility that can produce wide suitable renovation packages at a high volume and low cost.
Affordance-based Design Method: A Case Study of University Campus
Authors: Gupta D , Uma Maheswari J 
Published: September 2019

Abstract
Development of a built environment encompasses urban design, land use, transportation system, and accommodates patterns of human activity within the physical environment. Holistic development of built environment requires a multidisciplinary design team of urban planners, architects and sustainability advisors from an early design stage. Literature and industry-practices show growth of designer’s techniques and competencies, sustainable development capabilities, and user-centric prospective in the early design. However, there is a lack of systematic method and all-inclusive approach to design a built environment. Thus, proposed research aims to develop a design method which is user-inspired, stakeholder conducive and environmentally conscious from an early design stage. To achieve this aim, an affordance-based design method is proposed and demonstrated through a case study of university campus. Affordance-based design method has been used for design of complex systems by capturing user needs, stakeholder ideas and generating design options. The proposed design method provides decision-making guidelines to designers, design space to incorporate stakeholders, and affordances to achieve sustainability. The proposed design method has potential to shift design and development of built environment from designer-controlled process to systematically organized process.
A case-based study on the use of life cycle assessment and life cycle costing in the building industry
Authors: Collin C , Olesen G G H , Qvist Secher A 
Published: September 2019

Abstract
The environmental impact of human activities has been a concern for engineers and architects for centuries, from limitation of energy and raw materials to predicting future energy and resource demands. This review demonstrates how life cycle assessment (LCA) and life cycle costing (LCC) tools can be used to support design decisions in the building industry throughout the design process. The study is primarily based on DGNB certification projects in Denmark conducted by the engineering consultancy company Ramboll and focuses on how LCA and LCC tools can be used in the early design stages to quantify decision making and how tools are used in the final stages of a certification process to verify the building geometry with regard to life cycle costs and environmental impacts.
New business models to support sustainable development: The case of energy-efficiency measures in buildings
Authors: Honold A , Lützkendorf T 
Published: September 2019

Abstract
The German government has set ambitious climate-protection targets to limit global warming. The aim is to achieve an energy-efficient and almost climate-neutral building stock by 2050. This applies particularly to buildings, responsible for more than 20% of CO2 emissions. The aim is to reduce the primary energy demand of buildings by 80% by the end of 2050. Achieving a nearly climate-neutral building stock requires targeted modernization measures that contribute to increasing energy efficiency. Barriers confronting the implementation of energy-efficient measures include lack of knowledge due to inadequate provision of information, lack of trust, and problems regarding financing possibilities. Therefore, solutions are needed for holistic concepts that make energy-efficient building and modernization more attractive. In addition to traditional business models (BM), measures that accelerate the implementation of energy-efficiency and BM that support the sustainable development of potential customers are sought. Expert knowledge must be shared to close information gaps; savings guarantees must be considered to build trust, and finally, financing possibilities must be available to support implementing sustainable measures. The research focuses on a modification of BM under the aspect of increasing energy efficiency in buildings for customers. This approach considers specific functions, effects, and benefits of BM. The aim of this extension is to create a basis for systematizing existing BM on the one hand, and on the other, to extend the proposed methodology. Finally, the developed guide supports startups designing new BM.
Defining a framework to apply retrofitting optimisation models for long-term and step-by-step renovation approaches
Authors: Maia I , Kranzl L 
Published: September 2019

Abstract
The recast of Energy Performance of Buildings Directive (EPBD) 2018/844/EU introduced in the article 19a the possibility of building renovation passports which provide a long-term and step-by-step deep renovation roadmap for a specific building. Preliminary results showed that optimisation models for deep renovation of existing building almost exclusively optimise single stage retrofitting. Different from the single stage approach, in the step-by-step approach the retrofitting measures are not performed at the same time. In the present study, we aim to understand how the methodological approach of optimisation models for single stage retrofitting can be adapted to a step-by-step renovation concept. For this, first, the existing optimisation models were compared in terms of integration with external tools for energy demand calculation, definition of the renovation measures, objective function, and the question to which extent they consider long-term dynamic aspects of step-wise retrofitting optimisation over several years or even decades. Second, after identifying possible obstacles for adapting existing optimisation approaches towards step-by-step renovation, a framework for a step by step renovation optimisation model was outlined. The framework defines how the single stage retrofitting measures could be broken down in different renovation steps over a period of several years or even decades and which criteria should determine the time-wise prioritisation of the retrofitting measures. With this approach, we prepare the ground for the development of innovative tools, supporting the provision of individual renovation roadmaps. Next steps of the present study are testing and improving the outlined optimisation approach, as well as, extending the results to a building stock scale. By that, we aim to develop a method for analysing possible impacts of step-by-step renovation measures on achieving building stock’s decarbonisation targets.
Mobilizing Low Carbon Transition: Transnational Practice of Energy Efficiency in the Urban Building Sector
Authors: Feng K , Schmidt J A 
Published: September 2019

Abstract
In many countries worldwide, low carbon sustainable transition has been planned and implemented through decoupling the economic growth from GHG emissions. Some nations are leading the scene by developing corresponding low carbon development strategies and policy measures to encourage socio-technical innovations. One of the key areas for low carbon urban development is the energy efficiency in buildings. The tendency of the rapidly growing population and urbanization asks for better narratives and practices improving the built environment. Cities and countries are keen on learning from best practice. Through international joint development projects, the “knowledge resources” - transnational, governmental, NGOs, practitioners, and academic actors - are disseminating the low carbon urban development ideas globally. What drives a successful translation of knowledge emerged from one social, economic, cultural, political, climatic and geographical context into a new one needs better clarification. This study explores the process of global circulation of sustainable innovation from a mobility and transition perspective. A conceptual framework is explored and tested through analysing the Passive House concept transferred from Germany to China. The study shows how the succinct form, co-evolving and re-contextualising attributes are key factors in circulating urban sustainability across context. Acknowledging the notion of adaptation and mutation in the translation process is a first step to address the discrepancies between the knowledge lending and receiving side, and further to foster the transformative learning.
A top-down approach for setting climate targets for buildings: the case of a New Zealand detached house
Authors: Chandrakumar C , McLaren S J , Dowdell D , Jaques R 
Published: September 2019

Abstract
Climate change mitigation requires the construction of low/zero-carbon buildings, and this is a challenge for designers. The use of Life Cycle Assessment (LCA) provides useful information to support eco-efficiency improvements and therefore, to reduce the climate impacts of building designs. However, it does not provide information about whether a proposed design aligns with achieving the global climate target of limiting global warming to below 1.5°C or 2°C. This study, therefore, introduces an LCA-based top-down approach for setting climate targets for the whole life cycle of buildings in terms of greenhouse gas emissions. It involves assigning a share of the 2°C global carbon budget for 2018-2050 to a country, to the construction sector of the country, and finally to a building. The approach includes a stock model that accounts for the projected growth in the number of buildings and associated climate impacts in a country up to 2050. The proposed approach was applied to a detached house in New Zealand, the most common residential building type in the country; it was found that the climate target of a New Zealand detached house over a 90-year lifetime is 71 tCO2eq. This modelling approach has potential to guide designers and other interested stakeholders in development of building designs enabling the building sector to operate within a selected global climate target (such as the 1.5°C or 2°C target).